Lancair Legacy Design Flaw?

[Gregory Hall]

<http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg>

Look at the picture. It's easy to see why the Lancair is dangerous. The
horizontal stabilizers appear to be on the too small side. This would result
in their stalling before the wing. Then the aircraft would pitch up making
the main wing stall. Ill-conceived, IMO.

A good lawyer needs to get on this with respect to BadWaterBill's untimely
demise.

--
Gregory Hall

[Vaughn Simon]

"Gregory Hall" > wrote in message
...
> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg>

> A good lawyer needs to get on this with respect to BadWaterBill's untimely
> demise.

With all due respect, that is a terrible idea. I think we already have too
many lawyers involved in GA's affairs. The Lancair is a homebuilt, experimental
aircraft; "You pays your money and you takes your chances" AKA, caveat emptor .

Vaughn

[Stuart Fields]

"Gregory Hall" > wrote in message
...
> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg>
>
> Look at the picture. It's easy to see why the Lancair is dangerous. The
> horizontal stabilizers appear to be on the too small side. This would
> result in their stalling before the wing. Then the aircraft would pitch up
> making the main wing stall. Ill-conceived, IMO.
>
> A good lawyer needs to get on this with respect to BadWaterBill's untimely
> demise.
>
> --
> Gregory Hall

Are you proposing a Lawyer for horizontal stabilizer design review? My
guess is that if you have been able to do a review of the horizontal stab
from a photo, that BwB would have a good idea of just what he was flying and
as the PIC was responsible for the safe operation of the bird. What a
Lawyer could add to this tragedy without creating a second tragedy is not
clear.

[Gregory Hall]

"Bryan Martin" > wrote in message
...
> That could only happen if the plane was loaded with the CG way aft of
> the limit. Otherwise, the plane would pitch DOWN if the stabilizer
> stalled because the stabilizer normally produces a down force to keep
> the nose up.
>


If it worked that way it would be a built-in safety factor helping to
forestall a stall of the main wing. But suppose the motor died and the
aircraft was then a glider. One must glide nose down. The horizontal
stabilizer forcing the nose down would then cause the pilot to pull back on
the stick to counteract the forces for aft. If the stabilizer stalled in
this attitude the nose is supposed to pitch down but would it? The tail
might just continue to drop provided the main wing still gets traction??? CG
is dependent upon both lifting both control surfaces as well as weight
distribution.
--
Gregory Hall

>
> In article >,
> "Gregory Hall" > wrote:
>
>> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg>
>>
>> Look at the picture. It's easy to see why the Lancair is dangerous. The
>> horizontal stabilizers appear to be on the too small side. This would
>> result
>> in their stalling before the wing. Then the aircraft would pitch up
>> making
>> the main wing stall. Ill-conceived, IMO.
>>
>> A good lawyer needs to get on this with respect to BadWaterBill's
>> untimely
>> demise.
>>
>> --
>> Gregory Hall
>
> --
> Bryan Martin
> N61BM, CH 601 XL, Ram Subaru, Stratus redrive.

[Alan Baker]

In article >,
"Gregory Hall" > wrote:

> "Bryan Martin" > wrote in message
> ...
> > That could only happen if the plane was loaded with the CG way aft of
> > the limit. Otherwise, the plane would pitch DOWN if the stabilizer
> > stalled because the stabilizer normally produces a down force to keep
> > the nose up.
> >
>
>
> If it worked that way it would be a built-in safety factor helping to
> forestall a stall of the main wing. But suppose the motor died and the
> aircraft was then a glider. One must glide nose down. The horizontal
> stabilizer forcing the nose down would then cause the pilot to pull back on
> the stick to counteract the forces for aft. If the stabilizer stalled in
> this attitude the nose is supposed to pitch down but would it? The tail
> might just continue to drop provided the main wing still gets traction??? CG
> is dependent upon both lifting both control surfaces as well as weight
> distribution.

Sorry. But centre of *mass* (to use the correct term) is not in any way
dependent on the lift from anything.

The centre of mass is a parameter than is completely fixed by the
distribution of the mass of the aircraft's components. Whether any
surface is providing lift will not change it.

So as long as the main wing is located aft of the centre of mass, the
aircraft will pitch *down* when lift from the tail plane is lost.

Period.

> --
> Gregory Hall
>
> >
> > In article >,
> > "Gregory Hall" > wrote:
> >
> >> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg
> >> >
> >>
> >> Look at the picture. It's easy to see why the Lancair is dangerous. The
> >> horizontal stabilizers appear to be on the too small side. This would
> >> result
> >> in their stalling before the wing. Then the aircraft would pitch up
> >> making
> >> the main wing stall. Ill-conceived, IMO.
> >>
> >> A good lawyer needs to get on this with respect to BadWaterBill's
> >> untimely
> >> demise.
> >>
> >> --
> >> Gregory Hall
> >
> > --
> > Bryan Martin
> > N61BM, CH 601 XL, Ram Subaru, Stratus redrive.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Rip[_3_]]

> If it worked that way it would be a built-in safety factor helping to
> forestall a stall of the main wing. But suppose the motor died and the
> aircraft was then a glider. One must glide nose down. The horizontal
> stabilizer forcing the nose down would then cause the pilot to pull back on
> the stick to counteract the forces for aft. If the stabilizer stalled in
> this attitude the nose is supposed to pitch down but would it? The tail
> might just continue to drop provided the main wing still gets traction??? CG
> is dependent upon both lifting both control surfaces as well as weight
> distribution.
> --
> Gregory Hall
>

You seem to have the forces on the horizontal stabilizer backwards. The
force on the horizontal is down, (NOT up as with the main wing) which is
why an aircraft is stable in pitch unless improper loading places the CG
too far aft.

Of course, non of this applies to canard designs, which the Lancair is not.

Rip

[cavelamb himself[_4_]]

Gregory Hall wrote:
> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg>
>
> Look at the picture. It's easy to see why the Lancair is dangerous. The
> horizontal stabilizers appear to be on the too small side. This would result
> in their stalling before the wing. Then the aircraft would pitch up making
> the main wing stall. Ill-conceived, IMO.
>
> A good lawyer needs to get on this with respect to BadWaterBill's untimely
> demise.
>
> --
> Gregory Hall
>
>

Bill would cuss you out for saying that.

And?

What is the area ratio of stab/wing?

Did you notice that the wing is tiny too?



--

Richard

(remove the X to email)

[Peter Dohm]

"cavelamb himself" > wrote in message
m...
> Gregory Hall wrote:
>> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg>
>>
>> Look at the picture. It's easy to see why the Lancair is dangerous. The
>> horizontal stabilizers appear to be on the too small side. This would
>> result in their stalling before the wing. Then the aircraft would pitch
>> up making the main wing stall. Ill-conceived, IMO.
>>
>> A good lawyer needs to get on this with respect to BadWaterBill's
>> untimely demise.
>>
>> --
>> Gregory Hall
>
> Bill would cuss you out for saying that.
>
> And?
>
> What is the area ratio of stab/wing?
>
> Did you notice that the wing is tiny too?
>
>
>
> --
>
> Richard
>
> (remove the X to email)

He seems to have missed a great deal, in just a few words.

Peter

[Gezellig]

On Tue, 28 Oct 2008 15:41:35 -0400, Gregory Hall wrote:

> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg>
>
> Look at the picture. It's easy to see why the Lancair is dangerous. The
> horizontal stabilizers appear to be on the too small side. This would result
> in their stalling before the wing. Then the aircraft would pitch up making
> the main wing stall. Ill-conceived, IMO.

Greg, no design theorist here but just because the hor stab "appears to
small" isn't much of an argument. The front wing of a canard compared to
the main wings is very small but the combo works in a pusher config. it
wouldn't appear to but it does.

Not knowing the camber and other details including the airflow to the
stabs makes the stalling prior argument unsubstantiated invho.

[Gezellig]

On Tue, 28 Oct 2008 17:12:50 -0400, Gregory Hall wrote:

> CG
> is dependent upon both lifting both control surfaces as well as weight
> distribution.

Thankfully that isn't the case otherwise you would have horrendous times
with energy management, for instance, with an ever evolving mass.

[Tech Support]

>> Look at the picture. It's easy to see why the Lancair is dangerous. The
>> horizontal stabilizers appear to be on the too small side. This would result
>> in their stalling before the wing. Then the aircraft would pitch up making
>> the main wing stall. Ill-conceived, IMO.

************************************************** *************

Any one ever look at the little tail on the ME-109?

A bitch to land but was told that was caused by the main gear
configuration.

Big John

[JohnO]

On Oct 29, 11:46*am, Alan Baker > wrote:
> In article >,
> *"Gregory Hall" > wrote:
>
>
>
> > "Bryan Martin" > wrote in message
> ...
> > > That could only happen if the plane was loaded with the CG way aft of
> > > the limit. Otherwise, the plane would pitch DOWN if the stabilizer
> > > stalled because the stabilizer normally produces a down force to keep
> > > the nose up.
>
> > If it worked that way it would be a built-in safety factor helping to
> > forestall a stall of the main wing. But suppose the motor died and the
> > aircraft was then a glider. One must glide nose down. The horizontal
> > stabilizer forcing the nose down would then cause the pilot to pull back on
> > the stick to counteract the forces for aft. If the stabilizer stalled in
> > this attitude the nose is supposed to pitch down but would it? The tail
> > might just continue to drop provided the main wing still gets traction??? CG
> > is dependent upon both lifting both control surfaces as well as weight
> > distribution.
>
> Sorry. But centre of *mass* (to use the correct term) is not in any way
> dependent on the lift from anything.
>
> The centre of mass is a parameter than is completely fixed by the
> distribution of the mass of the aircraft's components. Whether any
> surface is providing lift will not change it.
>
> So as long as the main wing is located aft of the centre of mass, the
> aircraft will pitch *down* when lift from the tail plane is lost.
>
> Period.
>
>
>
> > --
> > Gregory Hall
>
> > > In article >,
> > > "Gregory Hall" > wrote:
>
> > >> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy200...
>
> > >> Look at the picture. It's easy to see why the Lancair is dangerous. The
> > >> horizontal stabilizers appear to be on the too small side. This would
> > >> result
> > >> in their stalling before the wing. Then the aircraft would pitch up
> > >> making
> > >> the main wing stall. Ill-conceived, IMO.
>
> > >> A good lawyer needs to get on this with respect to BadWaterBill's
> > >> untimely
> > >> demise.
>
> > >> --
> > >> Gregory Hall
>
> > > --
> > > Bryan Martin
> > > N61BM, CH 601 XL, Ram Subaru, Stratus redrive.
>
> --
> Alan Baker
> Vancouver, British Columbia
> <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

It's kinda simple. Assuming the main wheels are under the wing and the
a/c still rests on those and the nose wheel then wings are aft of the
cg and the horizontal stabilisers are there for down force to keep the
nose up. Not sure what Gregory is banging on about here.

[Alan Baker]

In article
>,
JohnO > wrote:

> On Oct 29, 11:46*am, Alan Baker > wrote:
> > In article >,
> > *"Gregory Hall" > wrote:
> >
> >
> >
> > > "Bryan Martin" > wrote in message
> > ...
> > > > That could only happen if the plane was loaded with the CG way aft of
> > > > the limit. Otherwise, the plane would pitch DOWN if the stabilizer
> > > > stalled because the stabilizer normally produces a down force to keep
> > > > the nose up.
> >
> > > If it worked that way it would be a built-in safety factor helping to
> > > forestall a stall of the main wing. But suppose the motor died and the
> > > aircraft was then a glider. One must glide nose down. The horizontal
> > > stabilizer forcing the nose down would then cause the pilot to pull back
> > > on
> > > the stick to counteract the forces for aft. If the stabilizer stalled in
> > > this attitude the nose is supposed to pitch down but would it? The tail
> > > might just continue to drop provided the main wing still gets traction???
> > > CG
> > > is dependent upon both lifting both control surfaces as well as weight
> > > distribution.
> >
> > Sorry. But centre of *mass* (to use the correct term) is not in any way
> > dependent on the lift from anything.
> >
> > The centre of mass is a parameter than is completely fixed by the
> > distribution of the mass of the aircraft's components. Whether any
> > surface is providing lift will not change it.
> >
> > So as long as the main wing is located aft of the centre of mass, the
> > aircraft will pitch *down* when lift from the tail plane is lost.
> >
> > Period.
<snip>

> It's kinda simple. Assuming the main wheels are under the wing and the
> a/c still rests on those and the nose wheel then wings are aft of the
> cg and the horizontal stabilisers are there for down force to keep the
> nose up. Not sure what Gregory is banging on about here.

Well, it's not quite *that* simple. There's no rule that the wheels need
to be directly under the centre of lift of the wing, but yeah...
....basically that's it.

I have no idea how anyone can get the wrong headed idea that the centre
of mass of a rigid body can move around.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Dennis Johnson]

"Gregory Hall" > wrote in message
...
> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg>
>
> Look at the picture. It's easy to see why the Lancair is dangerous. The
> horizontal stabilizers appear to be on the too small side. This would
> result in their stalling before the wing. Then the aircraft would pitch up
> making the main wing stall. Ill-conceived, IMO.

I find your strange posting to be quite offensive in its serious charges
which are totally unfounded. As others have already pointed out, you are
fundamentally incorrect about the purpose of the horizontal stabilizer. The
horizontal tail holds the nose up, not down. Your assertion about the
Legacy's stall recovery just makes no sense at all.

By the way, the Lancair Legacy is the most fun civilian airplane I've flown
and is the main reason I returned to general aviation after a decades-long
absence. I'm sure there is a Legacy near you and I'll bet its pilot would
be happy to take you for a ride. You can see for yourself what a great
airplane it is.

Dennis

[Ron Wanttaja]

On Tue, 28 Oct 2008 15:41:35 -0400, "Gregory Hall" > wrote:

> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg>
>
> Look at the picture. It's easy to see why the Lancair is dangerous. The
> horizontal stabilizers appear to be on the too small side. This would result
> in their stalling before the wing. Then the aircraft would pitch up making
> the main wing stall. Ill-conceived, IMO.
>
> A good lawyer needs to get on this with respect to BadWaterBill's untimely
> demise.

Unfortunately, there are several factors at work that would reduce the chance of
success in a lawsuit against Lancair.

First, of course, there's nothing to say the size of the horizontal tail had any
bearing on this accident.

Second, Bill had been flying this aircraft for several years with nothing but
praise for the way it handled.

Third, Lancair wasn't the manufacturer of this airplane. All they did was
supply parts.

Finally, the situation is strongly muddied by the fact that aircraft was built
by a hired gun. The FAA doesn't list the certification category for Bill's
airplane (not uncommon...John Ammeter's RV-6 was the same way). But the builder
of his plane built two other Lancair Legacies completed at the same time as
Bill's and registered them as Amateur-Built (N36XX and N272AG).

*If* N151HT was also carried an Amateur-Built registration, I think Lancair
would have a strong case that the airplane was built under fraudulent
circumstances. I think it would be hard to show that Bill was unaware of it...

http://tinyurl.com/5atovq

....and I suspect most judges wouldn't be sympathetic.

Ron Wanttaja

[Ron Wanttaja]

Ron Wanttaja wrote:

> But the builder of his plane built two other Lancair Legacies completed
> at the same time as Bill's...

I'd meant to post "at *about* the same time." Bill's was completed in
early 2006, Legacy N36XX is also listed as a 2006 model, and Legacy
N272AG as a 2007. N36XX has a co-manufacturer listed and has a
significantly lower serial number; I'd speculate that this might have
been a previously-started project. Legacy N272AG and Legacy N151HT have
serial numbers just five numbers apart (L2K-267 and L2K-272).

Ron Wanttaja

[Gregory Hall]

"Dennis Johnson" > wrote in message
. ..
>
> "Gregory Hall" > wrote in message
> ...
>> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg>
>>
>> Look at the picture. It's easy to see why the Lancair is dangerous. The
>> horizontal stabilizers appear to be on the too small side. This would
>> result in their stalling before the wing. Then the aircraft would pitch
>> up making the main wing stall. Ill-conceived, IMO.
>
> I find your strange posting to be quite offensive in its serious charges
> which are totally unfounded. As others have already pointed out, you are
> fundamentally incorrect about the purpose of the horizontal stabilizer.
> The horizontal tail holds the nose up, not down. Your assertion about the
> Legacy's stall recovery just makes no sense at all.


I think it makes good sense. Look at the size of that engine up front. Looks
like a P-51 Mustang for pity sake. When you're being pulled along by that
big prop and heavy, powerful engine it pulls the nose of the aircraft down.
The horizontal stabilizers have to counteract this force by putting an
upward force on the nose by pushing the tail down. If and when the engine
suddenly dies the aircraft will pitch up suddenly and since the size of the
stabilizers are so puny they might easily stall and be unable to counteract
the upward pitch at the nose resulting in a tail down death spiral.

> By the way, the Lancair Legacy is the most fun civilian airplane I've
> flown and is the main reason I returned to general aviation after a
> decades-long absence. I'm sure there is a Legacy near you and I'll bet
> its pilot would be happy to take you for a ride. You can see for yourself
> what a great airplane it is.

It looks too much like an irresponsible, hot rod, stunt plane to me. Is it
any wonder so many companies offering homebuilt aircraft have gone out of
business?

http://www.homebuilt.org/aircraft/nolonger.html

This is the safest homebuilt IMO.(VariEze ). The canard makes it foolproof.

http://video.google.com.au/videoplay?docid=-7074107135477166441&hl=en

--
Gregory Hall

[Vaughn Simon]

"Gregory Hall" > wrote in message
...

>
> It looks too much like an irresponsible, hot rod, stunt plane to me.

Well, you sucked me in at first, so on a troll scale of zero-to-10 you rate
at least a five. How are things in France?

Vaughn

[Steve Hix]

In article >,
"Gregory Hall" > wrote:

> "Dennis Johnson" > wrote in message
> . ..
> >
> > I find your strange posting to be quite offensive in its serious charges
> > which are totally unfounded. As others have already pointed out, you are
> > fundamentally incorrect about the purpose of the horizontal stabilizer.
> > The horizontal tail holds the nose up, not down. Your assertion about the
> > Legacy's stall recovery just makes no sense at all.
>
> I think it makes good sense.

It makes absolutely backwards sense.

You need to do a bit more handwaving. Really.

Better, go find a local park and play on the teeter-totter for a while.

I'm serious.

> Look at the size of that engine up front. Looks
> like a P-51 Mustang for pity sake.

For fairly vague, and small, values of "P-51".

> When you're being pulled along by that
> big prop and heavy, powerful engine it pulls the nose of the aircraft down.

Even when the engine is not running, it's pulling the nose down. It's
called "weight", and it's constant.

> The horizontal stabilizers have to counteract this force by putting an
> upward force on the nose by pushing the tail down.

Good so far.

> If and when the engine suddenly dies the aircraft will pitch up suddenly

Nope. It will pitch *down* as the aircraft decelerates.

Think about it; the airflow over the stabilizer/stabilator/tail feathers
provides the down force at one end of the lever to compensate for the
downforce (engine/prop) at the other end of the lever.

Slow down and the down force at the tail end decreases, so that the down
force provided by the engine/prop is no longer exactly counterbalanced.

The aircraft will begin to accelerate downward as it pitches down (*not*
up). Given time and altitude, it will eventually stabilize in a descent,
at whatever speed it was trimmed for at the time the engine quit.

> and since the size of the
> stabilizers are so puny they might easily stall and be unable to counteract
> the upward pitch at the nose resulting in a tail down death spiral.

How in the world do you get this upward pitch? The engine is heavy, not
lighter than air, you know.

> > By the way, the Lancair Legacy is the most fun civilian airplane I've
> > flown and is the main reason I returned to general aviation after a
> > decades-long absence. I'm sure there is a Legacy near you and I'll bet
> > its pilot would be happy to take you for a ride. You can see for yourself
> > what a great airplane it is.
>
> It looks too much like an irresponsible, hot rod, stunt plane to me.

Looks like an aircraft designed for moderately high cruise speeds.

> Is it any wonder so many companies offering homebuilt aircraft have gone out of
> business?
>
> http://www.homebuilt.org/aircraft/nolonger.html

They mostly failed due to not enough customers, or by being inadequately
capitalized, and for other business reasons.

Or are you arguing that aircraft similar to the old Aeronca 7AC, Chief
or Sedan are gone now because they were all "irresponsible, hot rod,
stunt planes"?

[ Say, you're not related to the fellow who was trying to drum up
support for closing down airpark housing developments for being too
dangerous, are you? ]

> This is the safest homebuilt IMO.(VariEze ). The canard makes it foolproof.
>
> http://video.google.com.au/videoplay?docid=-7074107135477166441&hl=en

Tell it to some users of that type of aircraft who found more excitement
than they'd bargained for if they flew into light rain...

Or, say, John Denver, who was killed flying one a couple years back.

The canard didn't save him, did it?

As for your movie, do you have any idea what the aircraft's sink rate
might be while it isn't stalling there?

[Alan Baker]

In article >,
"Gregory Hall" > wrote:

> "Dennis Johnson" > wrote in message
> . ..
> >
> > "Gregory Hall" > wrote in message
> > ...
> >> <http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg
> >> >
> >>
> >> Look at the picture. It's easy to see why the Lancair is dangerous. The
> >> horizontal stabilizers appear to be on the too small side. This would
> >> result in their stalling before the wing. Then the aircraft would pitch
> >> up making the main wing stall. Ill-conceived, IMO.
> >
> > I find your strange posting to be quite offensive in its serious charges
> > which are totally unfounded. As others have already pointed out, you are
> > fundamentally incorrect about the purpose of the horizontal stabilizer.
> > The horizontal tail holds the nose up, not down. Your assertion about the
> > Legacy's stall recovery just makes no sense at all.
>
>
> I think it makes good sense. Look at the size of that engine up front. Looks
> like a P-51 Mustang for pity sake. When you're being pulled along by that
> big prop and heavy, powerful engine it pulls the nose of the aircraft down.
> The horizontal stabilizers have to counteract this force by putting an
> upward force on the nose by pushing the tail down. If and when the engine
> suddenly dies the aircraft will pitch up suddenly and since the size of the
> stabilizers are so puny they might easily stall and be unable to counteract
> the upward pitch at the nose resulting in a tail down death spiral.

More nonsense. The loss of thrust won't result in a sudden pitch-up. The
engines mass and the force of gravity acting on that mass don't
disappear when it stops producing power.

>
> > By the way, the Lancair Legacy is the most fun civilian airplane I've
> > flown and is the main reason I returned to general aviation after a
> > decades-long absence. I'm sure there is a Legacy near you and I'll bet
> > its pilot would be happy to take you for a ride. You can see for yourself
> > what a great airplane it is.
>
> It looks too much like an irresponsible, hot rod, stunt plane to me. Is it
> any wonder so many companies offering homebuilt aircraft have gone out of
> business?
>
> http://www.homebuilt.org/aircraft/nolonger.html
>
> This is the safest homebuilt IMO.(VariEze ). The canard makes it foolproof.
>
> http://video.google.com.au/videoplay?docid=-7074107135477166441&hl=en

Anyone who thinks an aircraft can be made "foolproof" is a fool who
shouldn't be flying.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[cavelamb himself[_4_]]

Alan Baker wrote:

> Anyone who thinks an aircraft can be made "foolproof" is a fool who
> shouldn't be flying.
>

You won this round, Alan!

--

Richard

(remove the X to email)

[Gregory Hall]

"Vaughn Simon" > wrote in message
...
>
> "Gregory Hall" > wrote in message
> ...
>
>>
>> It looks too much like an irresponsible, hot rod, stunt plane to me.
>
> Well, you sucked me in at first, so on a troll scale of zero-to-10 you
> rate at least a five. How are things in France?
>
> Vaughn


France? I don't live in France. I built and used to fly a Rotec Rally 2B
many years ago. It was a tail dragger with a high wing and the motor was
mounted atop the wind with a pusher prop.

When I got it trimmed out correctly at cruise speeds I could lean forward in
the seat to nose it down and lean back in the seat to nose it up. Even as
well-balanced as it was at about half throttle, when the engine quit it
would pitch up immediately and drastically because the high engine placement
and pusher prop had enough leverage so that the proper trim at the tail
counteracted the nose down force of the engine and prop. If you didn't
immediately push the stick way forward when the engine quit it was a matter
of seconds before it would nose up fast and stall and then you would have no
control at all from the stick until it fell for a while and the nose dropped
(thank god for that) so you could gain speed provided you had enough
altitude to get control of it again. But it didn't glide too well being a
single surface wing with wire bracing. Perhaps 2:1 glide ratio. But it was
easy to land with no power but you had to come in hot and steep and at the
last second pull back on the stick and flare it.

It looks to me like the Legacy would act pretty much the same if the engine
quit.

--
Gregory Hall

[BobR]

On Oct 30, 5:12*pm, "Gregory Hall" > wrote:
> "Vaughn Simon" > wrote in message
>
> ...
>
>
>
> > "Gregory Hall" > wrote in message
> ...
>
> >> It looks too much like an irresponsible, hot rod, stunt plane to me.
>
> > * Well, you sucked me in at first, so on a troll scale of zero-to-10 you
> > rate at least a five. *How are things in France?
>
> > Vaughn
>
> France? *I don't live in France. I built and used to fly a Rotec Rally 2B
> many years ago. It was a tail dragger with a high wing and the motor was
> mounted atop the wind with a pusher prop.
>
> When I got it trimmed out correctly at cruise speeds I could lean forward in
> the seat to nose it down and lean back in the seat to nose it up. Even as
> well-balanced as it was at about half throttle, when the engine quit it
> would pitch up immediately and drastically because the high engine placement
> and pusher prop had enough leverage so that the proper trim at the tail
> counteracted the nose down force of the engine and prop. If you didn't
> immediately push the stick way forward when the engine quit it was a matter
> of seconds before it would nose up fast and stall and then you would have no
> control at all from the stick until it fell for a while and the nose dropped
> (thank god for that) so you could gain speed provided you had enough
> altitude to get control of it again. But it didn't glide too well being a
> single surface wing with wire bracing. Perhaps 2:1 glide ratio. But it was
> easy to land with no power but you had to come in hot and steep and at the
> last second pull back on the stick and flare it.
>
> It looks to me like the Legacy would act pretty much the same if the engine
> quit.
>
> --
> Gregory Hall

Oh for gawd sake, you are talking about two totally different designs
and the aerodynamics of the two are totally different. The Lancair is
NOT a pusher and the engine is mounted forward of the CG instead of on
top of it. When the engine quits it will not pitch upward. The plane
you flew had the engine well above the center of gravity with a pusher
prop and as a result produced a force that pushed the nose of the
aircraft down. The two planes would not act pretty much the same at
all. The weight of the engine on the Legacy is forward of the CG and
as a result always pulling the nose of the plane down. The counter to
the nose down is the horizontal stabilizer and the elevator. Look at
the angle of incedence on the Horizontal Stabilizer and you will find
a slight downward angle, not an upward angle as is common on the
wing. This counteracts the force from the weight of the engine. An
engine out condition will not have a significant effect on pitch until
the airspeed changes and that will result in a nose down, not nose up
pull.

[Gezellig]

On Thu, 30 Oct 2008 16:36:16 -0400, Gregory Hall wrote:

> This is the safest homebuilt IMO.(VariEze ). The canard makes it foolproof.
>
> http://video.google.com.au/videoplay?docid=-7074107135477166441&hl=en

No, I have flown a Velocity and a Cozy and they are far from foolproof,
stall the canard and find out.

[Steve Hix]

In article
>,
Alan Baker > wrote:

>
> Anyone who thinks an aircraft can be made "foolproof" is a fool who
> shouldn't be flying.

Like Mignet and his Pou-du-Ciel (Flying Flea).

Everything going swimmingly, unless you manage to somehow get it
inverted.

At which point it becomes so stable that it would stooge about until it
ran out of fuel, no way to bring it upright again.

[Steve Hix]

In article >,
"Gregory Hall" > wrote:

> France? I don't live in France. I built and used to fly a Rotec Rally 2B
> many years ago. It was a tail dragger with a high wing and the motor was
> mounted atop the win[g] with a pusher prop.
>
> When I got it trimmed out correctly at cruise speeds I could lean forward in
> the seat to nose it down and lean back in the seat to nose it up.

Sort of like a Taylorcraft or Cessna 140 or similar small aircraft.

> Even as
> well-balanced as it was at about half throttle, when the engine quit it
> would pitch up immediately and drastically because the high engine placement

.... Placed the thrust line enough above the center of drag that adding
power caused a downward pitch moment, and reducing power resulted in a
upward pitch.

> and pusher prop had enough leverage so that the proper trim at the tail
> counteracted the nose down force of the engine and prop.

Which is what the horizontal stab/stabilator is for.

> If you didn't
> immediately push the stick way forward when the engine quit it was a matter
> of seconds before it would nose up fast and stall and then you would have no
> control at all from the stick until it fell for a while and the nose dropped
> (thank god for that) so you could gain speed provided you had enough
> altitude to get control of it again. But it didn't glide too well being a
> single surface wing with wire bracing. Perhaps 2:1 glide ratio. But it was
> easy to land with no power but you had to come in hot and steep and at the
> last second pull back on the stick and flare it.
>
> It looks to me like the Legacy would act pretty much the same if the engine
> quit.

Except for the Legacy not incorporating those design elements that
result in the pitch/power response of the Rotec Rally. The Rally needs a
lot of upward pitch dialed in for level cruise (which ought to be
contributing a lot of drag as an added bonus), giving you some nasty
response to losing power.

In particular, both thrust and drag components in the Legacy are much
closer in alignment, resulting in much less pitch change when power
changes.

The two aircraft behave very differently in many aspects, and the Legacy
not much at all as you've asserted.

[Ernest Christley]

Gregory Hall wrote:

> I think it makes good sense. Look at the size of that engine up front. Looks
> like a P-51 Mustang for pity sake. When you're being pulled along by that
> big prop and heavy, powerful engine it pulls the nose of the aircraft down.
> The horizontal stabilizers have to counteract this force by putting an
> upward force on the nose by pushing the tail down. If and when the engine
> suddenly dies the aircraft will pitch up suddenly and since the size of the
> stabilizers are so puny they might easily stall and be unable to counteract
> the upward pitch at the nose resulting in a tail down death spiral.
>

Good try, Greg, but there is so much that you have left out, or just
have plane wrong (yuk! yuk!). I'll just point out one thing that I
haven't seen anyone else mention.

Engine offset.

How an airplane behaves power-on vs. power-off can be be radically
modified with a few shims that will shift the direction the engine is
pulling. Left to right. Up to down. The numbers will be specified
with high accuracy in a set of plans. The Dyke Delta has 2/3 degree
upthrust. When you apply power it pulls the nose up. Drop power and so
does the nose. Makes for a more stable speed. There is no way you
could ever get those details from a picture over the internet.

[Dan[_12_]]

Alan Baker wrote:
<snip>
>
> Anyone who thinks an aircraft can be made "foolproof" is a fool who
> shouldn't be flying.
>

When someone invents something foolproof someone else invents a
better fool.

Dan, U.S. Air Force, retired

[Morgans[_2_]]

"Steve Hix" > wrote
> Like Mignet and his Pou-du-Ciel (Flying Flea).
>
> Everything going swimmingly, unless you manage to somehow get it
> inverted.
>
> At which point it becomes so stable that it would stooge about until it
> ran out of fuel, no way to bring it upright again.

How about half of an outside loop?
--
Jim in NC

[Ron Wanttaja]

Gregory Hall wrote:

> This is the safest homebuilt IMO.(VariEze ). The canard makes it foolproof.

If that were the case, the Velocity would have a better safety record
than the Lancair family. Based on my statistics from 1999 through 2006,
it doesn't... the Velocity has about a 20% higher accident rate. In
fact, the Velocity has a rate almost three TIMES higher that of the RV
fleet. Which isn't doesn't use canards, either.

The difference in fleet size does affect the statistics, of course....

Ron Wanttaja

[Jim Logajan]

Ron Wanttaja > wrote:
> Gregory Hall wrote:
>
>> This is the safest homebuilt IMO.(VariEze ). The canard makes it
>> foolproof.
>
> If that were the case, the Velocity would have a better safety record
> than the Lancair family. Based on my statistics from 1999 through
> 2006, it doesn't... the Velocity has about a 20% higher accident rate.
> In fact, the Velocity has a rate almost three TIMES higher that of
> the RV fleet. Which isn't doesn't use canards, either.
>
> The difference in fleet size does affect the statistics, of course....

Still, it might be reasonably argued that when a Lancair aircraft is
involved in an accident, it has a higher probability of yielding fatalities
than other aircraft. Consider:

I did a simple NTSB search[1] (from 1-1-1962 to present) using "Lancair" in
the Make/Model field and it appears that out of 151 matching accident
records, 70 involved fatalities. Is that 46% value close to typical or is
it, as I suspect, on the high side[2]?

When I entered "Lancair Legacy" in the Make/Model field out of 11 matching
records 7 of them involved fatalities. The 63% value seems even more
unusual. But the accident count is a small number, so may be misleading.

(Yes - I know the entered keywords may not find all relevant records, but
I'm assuming the missed records have similar proportions of fatal to total
accidents as the matching records.)

If the fractions are not typical, could it be because Lancair
incidents/non-fatal "accidents" aren't reported as often as for other
makes? Or is the aircraft dangerously unforgiving such that an accident has
a high likelyhood of leading to fatalities? Or is there another reason for
the differences?

[1] http://www.ntsb.gov/ntsb/query.asp

[2] By comparison, from 1-1-1962 to present and entering "701" in
Make/Model and setting "Amateur Built" to Yes yielded 27 records for the
Zenith CH 701 aircraft. Only one of those records involved fatalities. Only
4% of accidents involved fatalities.

[Dan[_12_]]

Ron Wanttaja wrote:
> Gregory Hall wrote:
>
>> This is the safest homebuilt IMO.(VariEze ). The canard makes it
>> foolproof.
>
> If that were the case, the Velocity would have a better safety record
> than the Lancair family. Based on my statistics from 1999 through 2006,
> it doesn't... the Velocity has about a 20% higher accident rate. In
> fact, the Velocity has a rate almost three TIMES higher that of the RV
> fleet. Which isn't doesn't use canards, either.
>
> The difference in fleet size does affect the statistics, of course....
>
> Ron Wanttaja

I have long wondered if the canard fliers who have accidents are
assuming "canards are safer" and get careless.

Dan, U.S. Air Force, retired

[Ron Wanttaja]

(Apologies to Jim; I'm snipping quite a bit of his excellent posting and
quoting him a bit out of order.)

Jim Logajan wrote:
>
> Still, it might be reasonably argued that when a Lancair aircraft is
> involved in an accident, it has a higher probability of yielding fatalities
> than other aircraft. Consider:

[Snip]

> When I entered "Lancair Legacy" in the Make/Model field out of 11 matching
> records 7 of them involved fatalities. The 63% value seems even more
> unusual. But the accident count is a small number, so may be misleading.

[Snip]

> [2] By comparison, from 1-1-1962 to present and entering "701" in
> Make/Model and setting "Amateur Built" to Yes yielded 27 records for
> the Zenith CH 701 aircraft. Only one of those records involved
> fatalities. Only 4% of accidents involved fatalities.

The problem is separating the "This is due to the aircraft being a
Lancair" issues from the "This is a high-performance aircraft" ones.
The survivability of an accident is dependent on a huge number of
factors, but a big one is the speed involved. Energy is equal to the
mass times the velocity squared.

Obviously a Zenair undershooting and hitting the trees at 35 knots is
going to be MUCH more survivable than a Lancair hitting the same trees
at 80. The fatality rate *might* be the same, if a Zenair hit the trees
at 80, but there's no way to make a fair comparison.

One can certainly argue that the Zenair's ability to slow down makes it
a safer airplane. But then, if one wants performance at the HIGH end,
one usually has to give up somewhat at the low-end range. TANSTAAFL.

A better comparison would be that of planes of similar high-end
performance... Lancairs, Glasairs, and RV-8s, for instance.

I took a quick look at my database (which covers Jan 1999 through Dec.
2006). The results were practically a wash...36% of two-seat Lancair
accidents were fatal, vs. about 40% of Glasairs. RV-8s were right
between at 38%.

Digging a little more, RV-6s were at about 26%, RANS (all models) were
34%, Avid Flyers (all models) were 10%, and Zenairs (all models) were
22%. For anyone keeping score, about 30% of first-flight accidents kill
the pilot.

> (Yes - I know the entered keywords may not find all relevant records, but
> I'm assuming the missed records have similar proportions of fatal to total
> accidents as the matching records.)

Welcome to my world. :-)

> If the fractions are not typical, could it be because Lancair
> incidents/non-fatal "accidents" aren't reported as often as for other
> makes?

I would suspect the opposite. Lancairs are expensive airplanes. Bet
the vast majority of the owners have insurance, and the insurer probably
won't pay off if the accident isn't reported to the FAA. They're also
complex aircraft, which means it's tougher to just pull up with a
trailer and haul off the wreckage before the FAA gets there. Been known
to happen, locally...

Ron Wanttaja

[Steve Hix]

In article >,
"Morgans" > wrote:

> "Steve Hix" > wrote
> > Like Mignet and his Pou-du-Ciel (Flying Flea).
> >
> > Everything going swimmingly, unless you manage to somehow get it
> > inverted.
> >
> > At which point it becomes so stable that it would stooge about until it
> > ran out of fuel, no way to bring it upright again.
>
> How about half of an outside loop?

That was *if* you were lucky, having enough altitude to complete the
half outside loop before hitting the ground.

It was a problem involving interference between the two tandem wings of
the Flea. (The only controls available in the original Fleas were pitch,
controlled by tipping the front wing up or down, and rudder, which
controlled roll through a lot of dihedral inducing yaw-roll couple. They
were not very good at handling any crosswind component on landing, but
most were flown off large open fields, letting the pilot operate
directly into the wind.)

Suppose the pilot pushed the stick forward to gain speed. As the speed
built, up the rear wing, operating at a greater effective angle of
attack (being fed air from the front wing) would gain lift and pitch the
aircraft's nose further down.

The pilot's normal reaction would be to pull back on the stick, which
increased the front wing's angle of attack by lowering the trailing edge
of the wing.

Because the trailing edge of the front wing was close to the leading
edge of the rear wing, the front wing's downwash accelerated the air
over the rear wing increasing its lift and thus increasing pitch-down,
resulting in flight directly into the ground if you had insufficient
altitude.

If you had enough altitude, it would fly a half outside loop, and at
that point become so stable that there was no recovery from the inverted
flight.

Eventually, the design was tweaked to get around the problem, but not
all examples of the Flying Flea were updated.

[Gezellig]

On Thu, 30 Oct 2008 19:38:03 -0700, Ron Wanttaja wrote:

> Gregory Hall wrote:
>
>> This is the safest homebuilt IMO.(VariEze ). The canard makes it foolproof.
>
> If that were the case, the Velocity would have a better safety record
> than the Lancair family. Based on my statistics from 1999 through 2006,
> it doesn't... the Velocity has about a 20% higher accident rate. In
> fact, the Velocity has a rate almost three TIMES higher that of the RV
> fleet. Which isn't doesn't use canards, either.
>
> The difference in fleet size does affect the statistics, of course....
>
> Ron Wanttaja

Ron, do you judge from this that the Velocity (or the pusher/canards in
general) have basic design issues (such as the Lancair's low speed
regime history)?

[Gregory Hall]

"Steve Hix" > wrote in message
...
> In article >,
> "Gregory Hall" > wrote:
>
>> France? I don't live in France. I built and used to fly a Rotec Rally 2B
>> many years ago. It was a tail dragger with a high wing and the motor was
>> mounted atop the win[g] with a pusher prop.
>>
>> When I got it trimmed out correctly at cruise speeds I could lean forward
>> in
>> the seat to nose it down and lean back in the seat to nose it up.
>
> Sort of like a Taylorcraft or Cessna 140 or similar small aircraft.
>
>> Even as
>> well-balanced as it was at about half throttle, when the engine quit it
>> would pitch up immediately and drastically because the high engine
>> placement
>
> ... Placed the thrust line enough above the center of drag that adding
> power caused a downward pitch moment, and reducing power resulted in a
> upward pitch.
>
>> and pusher prop had enough leverage so that the proper trim at the tail
>> counteracted the nose down force of the engine and prop.
>
> Which is what the horizontal stab/stabilator is for.
>
>> If you didn't
>> immediately push the stick way forward when the engine quit it was a
>> matter
>> of seconds before it would nose up fast and stall and then you would have
>> no
>> control at all from the stick until it fell for a while and the nose
>> dropped
>> (thank god for that) so you could gain speed provided you had enough
>> altitude to get control of it again. But it didn't glide too well being a
>> single surface wing with wire bracing. Perhaps 2:1 glide ratio. But it
>> was
>> easy to land with no power but you had to come in hot and steep and at
>> the
>> last second pull back on the stick and flare it.
>>
>> It looks to me like the Legacy would act pretty much the same if the
>> engine
>> quit.
>
> Except for the Legacy not incorporating those design elements that
> result in the pitch/power response of the Rotec Rally. The Rally needs a
> lot of upward pitch dialed in for level cruise (which ought to be
> contributing a lot of drag as an added bonus), giving you some nasty
> response to losing power.
>
> In particular, both thrust and drag components in the Legacy are much
> closer in alignment, resulting in much less pitch change when power
> changes.
>
> The two aircraft behave very differently in many aspects, and the Legacy
> not much at all as you've asserted.


Thanks guys. I think I understand the differences now. The part about the
forces being in better alignment makes sense to me and pusher vs. puller.
I'll have to retract my ill-conceived statements about the Legacy. By bad!

--
Gregory Hall

[jan olieslagers[_2_]]

Dan schreef:

> When someone invents something foolproof someone else invents a better
> fool.

Think I'll use that for my e-mail signature for a while. Thank you!

[Alan Baker]

In article >,
cavelamb himself > wrote:

> Alan Baker wrote:
>
> > Anyone who thinks an aircraft can be made "foolproof" is a fool who
> > shouldn't be flying.
> >
>
> You won this round, Alan!

Thanks, I guess. But I prefer to win against an opponent who's a little
tougher than that...

:-)

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Alan Baker]

In article >,
"Gregory Hall" > wrote:

> "Vaughn Simon" > wrote in message
> ...
> >
> > "Gregory Hall" > wrote in message
> > ...
> >
> >>
> >> It looks too much like an irresponsible, hot rod, stunt plane to me.
> >
> > Well, you sucked me in at first, so on a troll scale of zero-to-10 you
> > rate at least a five. How are things in France?
> >
> > Vaughn
>
>
> France? I don't live in France. I built and used to fly a Rotec Rally 2B
> many years ago. It was a tail dragger with a high wing and the motor was
> mounted atop the wind with a pusher prop.
>
> When I got it trimmed out correctly at cruise speeds I could lean forward in
> the seat to nose it down and lean back in the seat to nose it up. Even as
> well-balanced as it was at about half throttle, when the engine quit it
> would pitch up immediately and drastically because the high engine placement
> and pusher prop had enough leverage so that the proper trim at the tail
> counteracted the nose down force of the engine and prop. If you didn't
> immediately push the stick way forward when the engine quit it was a matter
> of seconds before it would nose up fast and stall and then you would have no
> control at all from the stick until it fell for a while and the nose dropped
> (thank god for that) so you could gain speed provided you had enough
> altitude to get control of it again. But it didn't glide too well being a
> single surface wing with wire bracing. Perhaps 2:1 glide ratio. But it was
> easy to land with no power but you had to come in hot and steep and at the
> last second pull back on the stick and flare it.
>
> It looks to me like the Legacy would act pretty much the same if the engine
> quit.

Greg,

What was happening to you was not caused by the *weight* of the engine,
but the change from higher than CoM thrust creating a pitch down torque,
to higher than CoM drag creating a pitch up torque.

Congratulations: you've just rediscovered one disadvantage of having a
thrust line that doesn't go through the centre of mass.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Alan Baker]

In article
>,
BobR > wrote:

> On Oct 30, 5:12*pm, "Gregory Hall" > wrote:
> > "Vaughn Simon" > wrote in message
> >
> > ...
> >
> >
> >
> > > "Gregory Hall" > wrote in message
> > ...
> >
> > >> It looks too much like an irresponsible, hot rod, stunt plane to me.
> >
> > > * Well, you sucked me in at first, so on a troll scale of zero-to-10 you
> > > rate at least a five. *How are things in France?
> >
> > > Vaughn
> >
> > France? *I don't live in France. I built and used to fly a Rotec Rally 2B
> > many years ago. It was a tail dragger with a high wing and the motor was
> > mounted atop the wind with a pusher prop.
> >
> > When I got it trimmed out correctly at cruise speeds I could lean forward in
> > the seat to nose it down and lean back in the seat to nose it up. Even as
> > well-balanced as it was at about half throttle, when the engine quit it
> > would pitch up immediately and drastically because the high engine placement
> > and pusher prop had enough leverage so that the proper trim at the tail
> > counteracted the nose down force of the engine and prop. If you didn't
> > immediately push the stick way forward when the engine quit it was a matter
> > of seconds before it would nose up fast and stall and then you would have no
> > control at all from the stick until it fell for a while and the nose dropped
> > (thank god for that) so you could gain speed provided you had enough
> > altitude to get control of it again. But it didn't glide too well being a
> > single surface wing with wire bracing. Perhaps 2:1 glide ratio. But it was
> > easy to land with no power but you had to come in hot and steep and at the
> > last second pull back on the stick and flare it.
> >
> > It looks to me like the Legacy would act pretty much the same if the engine
> > quit.
> >
> > --
> > Gregory Hall
>
> Oh for gawd sake, you are talking about two totally different designs
> and the aerodynamics of the two are totally different. The Lancair is
> NOT a pusher and the engine is mounted forward of the CG instead of on
> top of it. When the engine quits it will not pitch upward. The plane
> you flew had the engine well above the center of gravity with a pusher
> prop and as a result produced a force that pushed the nose of the
> aircraft down. The two planes would not act pretty much the same at
> all. The weight of the engine on the Legacy is forward of the CG and
> as a result always pulling the nose of the plane down. The counter to
> the nose down is the horizontal stabilizer and the elevator. Look at
> the angle of incedence on the Horizontal Stabilizer and you will find
> a slight downward angle, not an upward angle as is common on the
> wing. This counteracts the force from the weight of the engine. An
> engine out condition will not have a significant effect on pitch until
> the airspeed changes and that will result in a nose down, not nose up
> pull.

The one thing not quite right is that there is no important difference
between tractor vs. pusher configurations with respect to directional
stability.

Like some of the early rocket designers (e.g. Goddard), you are falling
into the fallacy that somehow pulling is more stable than pushing. This
is not so.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[BobR]

On Oct 31, 2:09*pm, Alan Baker > wrote:
> In article
> >,
>
>
>
>
>
> *BobR > wrote:
> > On Oct 30, 5:12*pm, "Gregory Hall" > wrote:
> > > "Vaughn Simon" > wrote in message
>
> > ...
>
> > > > "Gregory Hall" > wrote in message
> > > ...
>
> > > >> It looks too much like an irresponsible, hot rod, stunt plane to me.
>
> > > > * Well, you sucked me in at first, so on a troll scale of zero-to-10 you
> > > > rate at least a five. *How are things in France?
>
> > > > Vaughn
>
> > > France? *I don't live in France. I built and used to fly a Rotec Rally 2B
> > > many years ago. It was a tail dragger with a high wing and the motor was
> > > mounted atop the wind with a pusher prop.
>
> > > When I got it trimmed out correctly at cruise speeds I could lean forward in
> > > the seat to nose it down and lean back in the seat to nose it up. Even as
> > > well-balanced as it was at about half throttle, when the engine quit it
> > > would pitch up immediately and drastically because the high engine placement
> > > and pusher prop had enough leverage so that the proper trim at the tail
> > > counteracted the nose down force of the engine and prop. If you didn't
> > > immediately push the stick way forward when the engine quit it was a matter
> > > of seconds before it would nose up fast and stall and then you would have no
> > > control at all from the stick until it fell for a while and the nose dropped
> > > (thank god for that) so you could gain speed provided you had enough
> > > altitude to get control of it again. But it didn't glide too well being a
> > > single surface wing with wire bracing. Perhaps 2:1 glide ratio. But it was
> > > easy to land with no power but you had to come in hot and steep and at the
> > > last second pull back on the stick and flare it.
>
> > > It looks to me like the Legacy would act pretty much the same if the engine
> > > quit.
>
> > > --
> > > Gregory Hall
>
> > Oh for gawd sake, you are talking about two totally different designs
> > and the aerodynamics of the two are totally different. *The Lancair is
> > NOT a pusher and the engine is mounted forward of the CG instead of on
> > top of it. *When the engine quits it will not pitch upward. *The plane
> > you flew had the engine well above the center of gravity with a pusher
> > prop and as a result produced a force that pushed the nose of the
> > aircraft down. *The two planes would not act pretty much the same at
> > all. *The weight of the engine on the Legacy is forward of the CG and
> > as a result always pulling the nose of the plane down. *The counter to
> > the nose down is the horizontal stabilizer and the elevator. *Look at
> > the angle of incedence on the Horizontal Stabilizer and you will find
> > a slight downward angle, not an upward angle as is common on the
> > wing. *This counteracts the force from the weight of the engine. *An
> > engine out condition will not have a significant effect on pitch until
> > the airspeed changes and that will result in a nose down, not nose up
> > pull.
>
> The one thing not quite right is that there is no important difference
> between tractor vs. pusher configurations with respect to directional
> stability.
>

Not sure what you are replying to but I never said anything about
directional stability. The discussion was regarding pitch forces.

> Like some of the early rocket designers (e.g. Goddard), you are falling
> into the fallacy that somehow pulling is more stable than pushing. This
> is not so.
>
> --
> Alan Baker
> Vancouver, British Columbia
> <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted text -
>
> - Show quoted text -

[Alan Baker]

In article
>,
BobR > wrote:

> On Oct 31, 2:09*pm, Alan Baker > wrote:
> > In article
> > >,
> >
> >
> >
> >
> >
> > *BobR > wrote:
> > > On Oct 30, 5:12*pm, "Gregory Hall" > wrote:
> > > > "Vaughn Simon" > wrote in message
> >
> > > ...
> >
> > > > > "Gregory Hall" > wrote in message
> > > > ...
> >
> > > > >> It looks too much like an irresponsible, hot rod, stunt plane to me.
> >
> > > > > * Well, you sucked me in at first, so on a troll scale of zero-to-10
> > > > > you
> > > > > rate at least a five. *How are things in France?
> >
> > > > > Vaughn
> >
> > > > France? *I don't live in France. I built and used to fly a Rotec Rally
> > > > 2B
> > > > many years ago. It was a tail dragger with a high wing and the motor
> > > > was
> > > > mounted atop the wind with a pusher prop.
> >
> > > > When I got it trimmed out correctly at cruise speeds I could lean
> > > > forward in
> > > > the seat to nose it down and lean back in the seat to nose it up. Even
> > > > as
> > > > well-balanced as it was at about half throttle, when the engine quit it
> > > > would pitch up immediately and drastically because the high engine
> > > > placement
> > > > and pusher prop had enough leverage so that the proper trim at the tail
> > > > counteracted the nose down force of the engine and prop. If you didn't
> > > > immediately push the stick way forward when the engine quit it was a
> > > > matter
> > > > of seconds before it would nose up fast and stall and then you would
> > > > have no
> > > > control at all from the stick until it fell for a while and the nose
> > > > dropped
> > > > (thank god for that) so you could gain speed provided you had enough
> > > > altitude to get control of it again. But it didn't glide too well being
> > > > a
> > > > single surface wing with wire bracing. Perhaps 2:1 glide ratio. But it
> > > > was
> > > > easy to land with no power but you had to come in hot and steep and at
> > > > the
> > > > last second pull back on the stick and flare it.
> >
> > > > It looks to me like the Legacy would act pretty much the same if the
> > > > engine
> > > > quit.
> >
> > > > --
> > > > Gregory Hall
> >
> > > Oh for gawd sake, you are talking about two totally different designs
> > > and the aerodynamics of the two are totally different. *The Lancair is
> > > NOT a pusher and the engine is mounted forward of the CG instead of on
> > > top of it. *When the engine quits it will not pitch upward. *The plane
> > > you flew had the engine well above the center of gravity with a pusher
> > > prop and as a result produced a force that pushed the nose of the
> > > aircraft down. *The two planes would not act pretty much the same at
> > > all. *The weight of the engine on the Legacy is forward of the CG and
> > > as a result always pulling the nose of the plane down. *The counter to
> > > the nose down is the horizontal stabilizer and the elevator. *Look at
> > > the angle of incedence on the Horizontal Stabilizer and you will find
> > > a slight downward angle, not an upward angle as is common on the
> > > wing. *This counteracts the force from the weight of the engine. *An
> > > engine out condition will not have a significant effect on pitch until
> > > the airspeed changes and that will result in a nose down, not nose up
> > > pull.
> >
> > The one thing not quite right is that there is no important difference
> > between tractor vs. pusher configurations with respect to directional
> > stability.
> >
>
> Not sure what you are replying to but I never said anything about
> directional stability. The discussion was regarding pitch forces.

Which is essentially the same thing.

Pusher or puller doesn't affect pitch forces. What affects pitch forces
is the length of the moment arm between the centre of mass and the
thrust line.

>
> > Like some of the early rocket designers (e.g. Goddard), you are falling
> > into the fallacy that somehow pulling is more stable than pushing. This
> > is not so.
> >
> > --
> > Alan Baker
> > Vancouver, British Columbia
> > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted
> > text -
> >
> > - Show quoted text -

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[cavelamb himself[_4_]]

Alan Baker wrote:

>
> The one thing not quite right is that there is no important difference
> between tractor vs. pusher configurations with respect to directional
> stability.
>
> Like some of the early rocket designers (e.g. Goddard), you are falling
> into the fallacy that somehow pulling is more stable than pushing. This
> is not so.
>

Actually, there is some difference in stability between tractor and pusher.

It's because of the volumn necesary to envlose the engine.
And the propeller disk.

Area (volumn) ahead of the CG should be considered destabalizing.

Conversly, (expecially propellers) aft of the CG contribute to better
stability.


--

Richard

(remove the X to email)

[Alan Baker]

In article >,
cavelamb himself > wrote:

> Alan Baker wrote:
>
> >
> > The one thing not quite right is that there is no important difference
> > between tractor vs. pusher configurations with respect to directional
> > stability.
> >
> > Like some of the early rocket designers (e.g. Goddard), you are falling
> > into the fallacy that somehow pulling is more stable than pushing. This
> > is not so.
> >
>
> Actually, there is some difference in stability between tractor and pusher.
>
> It's because of the volumn necesary to envlose the engine.
> And the propeller disk.
>
> Area (volumn) ahead of the CG should be considered destabalizing.
>
> Conversly, (expecially propellers) aft of the CG contribute to better
> stability.

That's a separate issue from tractor vs. pusher. True, the layout can
influence the volume question, but one is not a function of the other.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Jim Logajan]

Ron Wanttaja > wrote:
> I took a quick look at my database (which covers Jan 1999 through Dec.
> 2006). The results were practically a wash...36% of two-seat Lancair
> accidents were fatal, vs. about 40% of Glasairs. RV-8s were right
> between at 38%.
>
> Digging a little more, RV-6s were at about 26%, RANS (all models) were
> 34%, Avid Flyers (all models) were 10%, and Zenairs (all models) were
> 22%. For anyone keeping score, about 30% of first-flight accidents
> kill the pilot.

Thanks for digging through the numbers!

[Steve Hix]

In article
>,
Alan Baker > wrote:

> Pusher or puller doesn't affect pitch forces. What affects pitch forces
> is the length of the moment arm between the centre of mass and the
> thrust line.

Or center of drag vs thrust line?

[Alan Baker]

In article >,
Steve Hix > wrote:

> In article
> >,
> Alan Baker > wrote:
>
> > Pusher or puller doesn't affect pitch forces. What affects pitch forces
> > is the length of the moment arm between the centre of mass and the
> > thrust line.
>
> Or center of drag vs thrust line?

The problem with that is "centre of drag" changes.

Better to take all the separate moments for the various components about
the centre of mass.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[[email protected]]

On Fri, 31 Oct 2008 12:09:27 -0700, Alan Baker >
wrote:


>The one thing not quite right is that there is no important difference
>between tractor vs. pusher configurations with respect to directional
>stability.
>
>Like some of the early rocket designers (e.g. Goddard), you are falling
>into the fallacy that somehow pulling is more stable than pushing. This
>is not so.
Pusher or tractor makes virtually no difference, but the vast
majority of pilon mounted engines ARE pushers - and the pilon mounted
engine does have that nasty quirk.

[Flyingmonk[_1_]]

Very interesting post, keep it up guys.

Monk

[Ron Wanttaja]

Gezellig wrote:
> On Thu, 30 Oct 2008 19:38:03 -0700, Ron Wanttaja wrote:
>>> This is the safest homebuilt IMO.(VariEze ). The canard makes it foolproof.
>> If that were the case, the Velocity would have a better safety record
>> than the Lancair family. Based on my statistics from 1999 through 2006,
>> it doesn't... the Velocity has about a 20% higher accident rate. In
>> fact, the Velocity has a rate almost three TIMES higher that of the RV
>> fleet. Which isn't doesn't use canards, either.
>
> Ron, do you judge from this that the Velocity (or the pusher/canards in
> general) have basic design issues (such as the Lancair's low speed
> regime history)?

It's funny you should ask, because that was one of the questions I was
hoping to answer when I got into homebuilt accident analysis about five
years ago.

Still haven't answered it.

There are so many factors involved that I could spend years of full-time
work trying to dig them out. The fleet size of the Velocity is still
relatively low, for example, and as well all know, one or two extra
accidents can cause a disproportionate change.

I dug a bit deeper into my database, and extracted the accident-cause
data for about 20 homebuilt types. As I mentioned on my last post, the
Velocity has an accident rate generally higher than most. Yet, the
Velocity had nearly the LOWEST "stick and rudder error" rate. About 43%
of RV-6 accidents involved the pilot's handling of the aircraft, vs.
only 29% of the Velocities.

HOWEVER (geeze, there's ALWAYS a "however" when you analyze accident
statistics), the pilots in the Velocity accidents had about 25% more
flight hours than those involved in RV accidents, and *four times* the
hours than the average homebuilder involved in an accident.

Lower rates because they're easier to fly...or because more-experienced
pilots are flying them?

My analysis method is a bit different from the NTSB's, too. I look for
the first major event of the accident string, which means that if the
engine quits, I attribute the accident to the engine quitting. The NTSB
works a bit differently. If the investigator thinks the pilot should
have been able to safely land the aircraft despite the engine failure,
the cause of the accident is listed as pilot error.

So my "pilot failure" category does NOT take into account the difficulty
of handling the aircraft in an emergency situation. While my stats may
show the pilot error rate for the Velocity to be lower, the NTSB's may not.

Ron Wanttaja

[Ron Wanttaja]

Ron Wanttaja wrote:

> The problem is separating the "This is due to the aircraft being a
> Lancair" issues from the "This is a high-performance aircraft" ones. The
> survivability of an accident is dependent on a huge number of factors,
> but a big one is the speed involved. Energy is equal to the mass times
> the velocity squared.
>
> Obviously a Zenair undershooting and hitting the trees at 35 knots is
> going to be MUCH more survivable than a Lancair hitting the same trees
> at 80. The fatality rate *might* be the same, if a Zenair hit the trees
> at 80, but there's no way to make a fair comparison.

I had a rather sad realization after re-reading this. Bill took off
downwind on Runway 04. The closest reporting site (20 miles away) was
reporting wind at 190 degrees, 10-20 knots, and the first responders
said the winds were about the same at Parowan.

Bill's Lancair thus hit the ground 20 to 40 knots faster than if he'd
taken off into the wind. That's a LOT more energy.

It may not have ultimately made any difference...a descending left turn
after a takeoff in the other direction would have put him right in the
center of the town. But you have to wonder.

Ron Wanttaja

[Alan Baker]

In article >,
wrote:

> On Fri, 31 Oct 2008 12:09:27 -0700, Alan Baker >
> wrote:
>
>
> >The one thing not quite right is that there is no important difference
> >between tractor vs. pusher configurations with respect to directional
> >stability.
> >
> >Like some of the early rocket designers (e.g. Goddard), you are falling
> >into the fallacy that somehow pulling is more stable than pushing. This
> >is not so.
> Pusher or tractor makes virtually no difference, but the vast
> majority of pilon mounted engines ARE pushers - and the pilon mounted
> engine does have that nasty quirk.

Yup, but that's because the pylon (note spelling) places the thrust line
far above the centre of mass, creating a long moment arm.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Steve Hix]

In article
>,
Alan Baker > wrote:

> In article >,
> Steve Hix > wrote:
>
> > In article
> > >,
> > Alan Baker > wrote:
> >
> > > Pusher or puller doesn't affect pitch forces. What affects pitch forces
> > > is the length of the moment arm between the centre of mass and the
> > > thrust line.
> >
> > Or center of drag vs thrust line?
>
> The problem with that is "centre of drag" changes.

And, as it does, so would pitch resultants.

> Better to take all the separate moments for the various components about
> the centre of mass.

Which will change as airspeed/AOA/etc. change, right?

Come to think on it, the total moments of drag don't care about any
masses, just the shape(s) of the aircraft exterior.

[BobR]

On Oct 31, 2:59*pm, Alan Baker > wrote:
> In article
> >,
>
>
>
>
>
> *BobR > wrote:
> > On Oct 31, 2:09*pm, Alan Baker > wrote:
> > > In article
> > > >,
>
> > > *BobR > wrote:
> > > > On Oct 30, 5:12*pm, "Gregory Hall" > wrote:
> > > > > "Vaughn Simon" > wrote in message
>
> > > > ...
>
> > > > > > "Gregory Hall" > wrote in message
> > > > > ...
>
> > > > > >> It looks too much like an irresponsible, hot rod, stunt plane to me.
>
> > > > > > * Well, you sucked me in at first, so on a troll scale of zero-to-10
> > > > > > you
> > > > > > rate at least a five. *How are things in France?
>
> > > > > > Vaughn
>
> > > > > France? *I don't live in France. I built and used to fly a Rotec Rally
> > > > > 2B
> > > > > many years ago. It was a tail dragger with a high wing and the motor
> > > > > was
> > > > > mounted atop the wind with a pusher prop.
>
> > > > > When I got it trimmed out correctly at cruise speeds I could lean
> > > > > forward in
> > > > > the seat to nose it down and lean back in the seat to nose it up. Even
> > > > > as
> > > > > well-balanced as it was at about half throttle, when the engine quit it
> > > > > would pitch up immediately and drastically because the high engine
> > > > > placement
> > > > > and pusher prop had enough leverage so that the proper trim at the tail
> > > > > counteracted the nose down force of the engine and prop. If you didn't
> > > > > immediately push the stick way forward when the engine quit it was a
> > > > > matter
> > > > > of seconds before it would nose up fast and stall and then you would
> > > > > have no
> > > > > control at all from the stick until it fell for a while and the nose
> > > > > dropped
> > > > > (thank god for that) so you could gain speed provided you had enough
> > > > > altitude to get control of it again. But it didn't glide too well being
> > > > > a
> > > > > single surface wing with wire bracing. Perhaps 2:1 glide ratio. But it
> > > > > was
> > > > > easy to land with no power but you had to come in hot and steep and at
> > > > > the
> > > > > last second pull back on the stick and flare it.
>
> > > > > It looks to me like the Legacy would act pretty much the same if the
> > > > > engine
> > > > > quit.
>
> > > > > --
> > > > > Gregory Hall
>
> > > > Oh for gawd sake, you are talking about two totally different designs
> > > > and the aerodynamics of the two are totally different. *The Lancair is
> > > > NOT a pusher and the engine is mounted forward of the CG instead of on
> > > > top of it. *When the engine quits it will not pitch upward. *The plane
> > > > you flew had the engine well above the center of gravity with a pusher
> > > > prop and as a result produced a force that pushed the nose of the
> > > > aircraft down. *The two planes would not act pretty much the same at
> > > > all. *The weight of the engine on the Legacy is forward of the CG and
> > > > as a result always pulling the nose of the plane down. *The counter to
> > > > the nose down is the horizontal stabilizer and the elevator. *Look at
> > > > the angle of incedence on the Horizontal Stabilizer and you will find
> > > > a slight downward angle, not an upward angle as is common on the
> > > > wing. *This counteracts the force from the weight of the engine. *An
> > > > engine out condition will not have a significant effect on pitch until
> > > > the airspeed changes and that will result in a nose down, not nose up
> > > > pull.
>
> > > The one thing not quite right is that there is no important difference
> > > between tractor vs. pusher configurations with respect to directional
> > > stability.
>
> > Not sure what you are replying to but I never said anything about
> > directional stability. *The discussion was regarding pitch forces.
>
> Which is essentially the same thing.
>
> Pusher or puller doesn't affect pitch forces. What affects pitch forces
> is the length of the moment arm between the centre of mass and the
> thrust line.
>
>
>
> > > Like some of the early rocket designers (e.g. Goddard), you are falling
> > > into the fallacy that somehow pulling is more stable than pushing. This
> > > is not so.
>
> > > --
> > > Alan Baker
> > > Vancouver, British Columbia
> > > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted
> > > text -
>
> > > - Show quoted text -
>
> --
> Alan Baker
> Vancouver, British Columbia
> <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted text -
>
> - Show quoted text -

Again Alan, I never indicated any issue with pusher vs tractor. The
layout of the two planes being discussed is totally different. One
involved a tractor configuration with the thrust line being very near
the vertical center of gravity. The second involved an plane with the
engine mounted on a pylon with a thrust line well above the vertical
center of gravity. This configuration, rather it be a tractor or
pusher will induce nose down forces that must be countered by the
horizontal stabilizer with an upward force. This is contrary to the
standard configuration which requires a downward force to counter the
weight of the engine. The post I was replying to was trying to link
the characteristic of the pylon mounted configuration to the Legacy.

[Alan Baker]

In article >,
Steve Hix > wrote:

> In article
> >,
> Alan Baker > wrote:
>
> > In article >,
> > Steve Hix > wrote:
> >
> > > In article
> > > >,
> > > Alan Baker > wrote:
> > >
> > > > Pusher or puller doesn't affect pitch forces. What affects pitch forces
> > > > is the length of the moment arm between the centre of mass and the
> > > > thrust line.
> > >
> > > Or center of drag vs thrust line?
> >
> > The problem with that is "centre of drag" changes.
>
> And, as it does, so would pitch resultants.
>
> > Better to take all the separate moments for the various components about
> > the centre of mass.
>
> Which will change as airspeed/AOA/etc. change, right?

No. The centre of mass *never* changes (in the context of this
discussion.

>
> Come to think on it, the total moments of drag don't care about any
> masses, just the shape(s) of the aircraft exterior.

You have to take moments about something that isn't going to shift,
Steve. Centre of mass.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Alan Baker]

In article
>,
BobR > wrote:

> On Oct 31, 2:59*pm, Alan Baker > wrote:
> > In article
> > >,
> >
> >
> >
> >
> >
> > *BobR > wrote:
> > > On Oct 31, 2:09*pm, Alan Baker > wrote:
> > > > In article
> > > > >,
> >
> > > > *BobR > wrote:
> > > > > On Oct 30, 5:12*pm, "Gregory Hall" > wrote:
> > > > > > "Vaughn Simon" > wrote in message
> >
> > > > > ...
> >
> > > > > > > "Gregory Hall" > wrote in message
> > > > > > ...
> >
> > > > > > >> It looks too much like an irresponsible, hot rod, stunt plane to
> > > > > > >> me.
> >
> > > > > > > * Well, you sucked me in at first, so on a troll scale of
> > > > > > > zero-to-10
> > > > > > > you
> > > > > > > rate at least a five. *How are things in France?
> >
> > > > > > > Vaughn
> >
> > > > > > France? *I don't live in France. I built and used to fly a Rotec
> > > > > > Rally
> > > > > > 2B
> > > > > > many years ago. It was a tail dragger with a high wing and the
> > > > > > motor
> > > > > > was
> > > > > > mounted atop the wind with a pusher prop.
> >
> > > > > > When I got it trimmed out correctly at cruise speeds I could lean
> > > > > > forward in
> > > > > > the seat to nose it down and lean back in the seat to nose it up.
> > > > > > Even
> > > > > > as
> > > > > > well-balanced as it was at about half throttle, when the engine
> > > > > > quit it
> > > > > > would pitch up immediately and drastically because the high engine
> > > > > > placement
> > > > > > and pusher prop had enough leverage so that the proper trim at the
> > > > > > tail
> > > > > > counteracted the nose down force of the engine and prop. If you
> > > > > > didn't
> > > > > > immediately push the stick way forward when the engine quit it was
> > > > > > a
> > > > > > matter
> > > > > > of seconds before it would nose up fast and stall and then you
> > > > > > would
> > > > > > have no
> > > > > > control at all from the stick until it fell for a while and the
> > > > > > nose
> > > > > > dropped
> > > > > > (thank god for that) so you could gain speed provided you had
> > > > > > enough
> > > > > > altitude to get control of it again. But it didn't glide too well
> > > > > > being
> > > > > > a
> > > > > > single surface wing with wire bracing. Perhaps 2:1 glide ratio. But
> > > > > > it
> > > > > > was
> > > > > > easy to land with no power but you had to come in hot and steep and
> > > > > > at
> > > > > > the
> > > > > > last second pull back on the stick and flare it.
> >
> > > > > > It looks to me like the Legacy would act pretty much the same if
> > > > > > the
> > > > > > engine
> > > > > > quit.
> >
> > > > > > --
> > > > > > Gregory Hall
> >
> > > > > Oh for gawd sake, you are talking about two totally different designs
> > > > > and the aerodynamics of the two are totally different. *The Lancair
> > > > > is
> > > > > NOT a pusher and the engine is mounted forward of the CG instead of
> > > > > on
> > > > > top of it. *When the engine quits it will not pitch upward. *The
> > > > > plane
> > > > > you flew had the engine well above the center of gravity with a
> > > > > pusher
> > > > > prop and as a result produced a force that pushed the nose of the
> > > > > aircraft down. *The two planes would not act pretty much the same at
> > > > > all. *The weight of the engine on the Legacy is forward of the CG and
> > > > > as a result always pulling the nose of the plane down. *The counter
> > > > > to
> > > > > the nose down is the horizontal stabilizer and the elevator. *Look at
> > > > > the angle of incedence on the Horizontal Stabilizer and you will find
> > > > > a slight downward angle, not an upward angle as is common on the
> > > > > wing. *This counteracts the force from the weight of the engine. *An
> > > > > engine out condition will not have a significant effect on pitch
> > > > > until
> > > > > the airspeed changes and that will result in a nose down, not nose up
> > > > > pull.
> >
> > > > The one thing not quite right is that there is no important difference
> > > > between tractor vs. pusher configurations with respect to directional
> > > > stability.
> >
> > > Not sure what you are replying to but I never said anything about
> > > directional stability. *The discussion was regarding pitch forces.
> >
> > Which is essentially the same thing.
> >
> > Pusher or puller doesn't affect pitch forces. What affects pitch forces
> > is the length of the moment arm between the centre of mass and the
> > thrust line.
> >
> >
> >
> > > > Like some of the early rocket designers (e.g. Goddard), you are falling
> > > > into the fallacy that somehow pulling is more stable than pushing. This
> > > > is not so.
> >
> > > > --
> > > > Alan Baker
> > > > Vancouver, British Columbia
> > > > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted
> > > > text -
> >
> > > > - Show quoted text -
> >
> > --
> > Alan Baker
> > Vancouver, British Columbia
> > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted
> > text -
> >
> > - Show quoted text -
>
> Again Alan, I never indicated any issue with pusher vs tractor. The
> layout of the two planes being discussed is totally different. One
> involved a tractor configuration with the thrust line being very near
> the vertical center of gravity. The second involved an plane with the
> engine mounted on a pylon with a thrust line well above the vertical
> center of gravity. This configuration, rather it be a tractor or
> pusher will induce nose down forces that must be countered by the
> horizontal stabilizer with an upward force. This is contrary to the
> standard configuration which requires a downward force to counter the
> weight of the engine. The post I was replying to was trying to link
> the characteristic of the pylon mounted configuration to the Legacy.

Sorry, man, but you made specific reference to the plane being a pusher
as if it was a relevant factor:

"The Lancair is NOT a pusher and the engine is mounted forward of the CG
instead of on top of it. *When the engine quits it will not pitch
upward. *The plane you flew had the engine well above the center of
gravity with a pusher prop and as a result produced a force that pushed
the nose of the aircraft down."

When you include extraneous details, you make the essence of the
situation harder to glean.

And you're doing it again. You're conflating thrust line induced pitch
changes with weight of engine. One is changing, one is constant.

The only part that you had to talk about was the fact that the thrust
line was significantly above the centre of mass. The weight of the
engine doesn't matter (in an aircraft that has it's centre of gravity
appropriately located), nor does pusher vs. puller.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Steve Hix]

In article
>,
Alan Baker > wrote:

> In article >,
> Steve Hix > wrote:
>
> > In article
> > >,
> > Alan Baker > wrote:
> >
> > > In article >,
> > > Steve Hix > wrote:
> > >
> > > > In article
> > > > >,
> > > > Alan Baker > wrote:
> > > >
> > > > > Pusher or puller doesn't affect pitch forces. What affects pitch
> > > > > forces
> > > > > is the length of the moment arm between the centre of mass and the
> > > > > thrust line.
> > > >
> > > > Or center of drag vs thrust line?
> > >
> > > The problem with that is "centre of drag" changes.
> >
> > And, as it does, so would pitch resultants.
> >
> > > Better to take all the separate moments for the various components about
> > > the centre of mass.
> >
> > Which will change as airspeed/AOA/etc. change, right?
>
> No. The centre of mass *never* changes (in the context of this
> discussion.
>
No, mass (other than fuel onboard) doesn't. But drag components can
change with changes in speed, AOA, flap positions, landing gear, cooling
flaps, etc.
>
> > Come to think on it, the total moments of drag don't care about any
> > masses, just the shape(s) of the aircraft exterior.
>
> You have to take moments about something that isn't going to shift,
> Steve. Centre of mass.

I know that that doesn't change (ignoring fuel burn), but things like
flaps' contribution to drag moments changes with changes in
configuration.

Else we'd never see pitch changes as we raise or lower the flaps, or
changes in speed as landing gear are retracted or extended.

[Alan Baker]

In article >,
Steve Hix > wrote:

> In article
> >,
> Alan Baker > wrote:
>
> > In article >,
> > Steve Hix > wrote:
> >
> > > In article
> > > >,
> > > Alan Baker > wrote:
> > >
> > > > In article >,
> > > > Steve Hix > wrote:
> > > >
> > > > > In article
> > > > > >,
> > > > > Alan Baker > wrote:
> > > > >
> > > > > > Pusher or puller doesn't affect pitch forces. What affects pitch
> > > > > > forces
> > > > > > is the length of the moment arm between the centre of mass and the
> > > > > > thrust line.
> > > > >
> > > > > Or center of drag vs thrust line?
> > > >
> > > > The problem with that is "centre of drag" changes.
> > >
> > > And, as it does, so would pitch resultants.
> > >
> > > > Better to take all the separate moments for the various components
> > > > about
> > > > the centre of mass.
> > >
> > > Which will change as airspeed/AOA/etc. change, right?
> >
> > No. The centre of mass *never* changes (in the context of this
> > discussion.
> >
> No, mass (other than fuel onboard) doesn't. But drag components can
> change with changes in speed, AOA, flap positions, landing gear, cooling
> flaps, etc.

Right. So take moments about the thing that doesn't change.

> >
> > > Come to think on it, the total moments of drag don't care about any
> > > masses, just the shape(s) of the aircraft exterior.
> >
> > You have to take moments about something that isn't going to shift,
> > Steve. Centre of mass.
>
> I know that that doesn't change (ignoring fuel burn), but things like
> flaps' contribution to drag moments changes with changes in
> configuration.
>
> Else we'd never see pitch changes as we raise or lower the flaps, or
> changes in speed as landing gear are retracted or extended.

Right. But trying to take moments about a centre of drag that is
changing because of the very thing causing you to take the moments in
the first place is a recipe for madness.

Just take them about the centre of mass!

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Steve Hix]

In article
>,
Alan Baker > wrote:

> In article >,
> Steve Hix > wrote:
>
> > In article
> > >,
> > Alan Baker > wrote:
> >
> > > In article >,
> > > Steve Hix > wrote:
> > >
> > > > In article
> > > > >,
> > > > Alan Baker > wrote:
> > > >
> > > > > In article >,
> > > > > Steve Hix > wrote:
> > > > >
> > > > > > In article
> > > > > > >,
> > > > > > Alan Baker > wrote:
> > > > > >
> > > > > > > Pusher or puller doesn't affect pitch forces. What affects pitch
> > > > > > > forces
> > > > > > > is the length of the moment arm between the centre of mass and
> > > > > > > the
> > > > > > > thrust line.
> > > > > >
> > > > > > Or center of drag vs thrust line?
> > > > >
> > > > > The problem with that is "centre of drag" changes.
> > > >
> > > > And, as it does, so would pitch resultants.
> > > >
> > > > > Better to take all the separate moments for the various components
> > > > > about
> > > > > the centre of mass.
> > > >
> > > > Which will change as airspeed/AOA/etc. change, right?
> > >
> > > No. The centre of mass *never* changes (in the context of this
> > > discussion.
> > >
> > No, mass (other than fuel onboard) doesn't. But drag components can
> > change with changes in speed, AOA, flap positions, landing gear, cooling
> > flaps, etc.
>
> Right. So take moments about the thing that doesn't change.

Looks to me that we're in something resembling violent agreement.

The center of mass doesn't change (ignoring fuel burn).

The drag components measured from that center certainly do, however.

[Morgans[_2_]]

"Alan Baker" > wrote

> Right. But trying to take moments about a centre of drag that is
> changing because of the very thing causing you to take the moments in
> the first place is a recipe for madness.
>
> Just take them about the centre of mass!

It matters not what you take the moments from, as long as it is from a
stationary reference on the plane.
--
Jim in NC

[Gezellig]

>> Ron, do you judge from this that the Velocity (or the pusher/canards in
>> general) have basic design issues (such as the Lancair's low speed
>> regime history)?

On Fri, 31 Oct 2008 17:58:28 -0700, Ron Wanttaja wrote:

> It's funny you should ask, because that was one of the questions I was
> hoping to answer when I got into homebuilt accident analysis about five
> years ago.
>
> Still haven't answered it.
>
> There are so many factors involved that I could spend years of full-time
> work trying to dig them out. The fleet size of the Velocity is still
> relatively low, for example, and as well all know, one or two extra
> accidents can cause a disproportionate change.
>
> I dug a bit deeper into my database, and extracted the accident-cause
> data for about 20 homebuilt types. As I mentioned on my last post, the
> Velocity has an accident rate generally higher than most. Yet, the
> Velocity had nearly the LOWEST "stick and rudder error" rate. About 43%
> of RV-6 accidents involved the pilot's handling of the aircraft, vs.
> only 29% of the Velocities.
>
> HOWEVER (geeze, there's ALWAYS a "however" when you analyze accident
> statistics), the pilots in the Velocity accidents had about 25% more
> flight hours than those involved in RV accidents, and *four times* the
> hours than the average homebuilder involved in an accident.
>
> Lower rates because they're easier to fly...or because more-experienced
> pilots are flying them?
>
> My analysis method is a bit different from the NTSB's, too. I look for
> the first major event of the accident string, which means that if the
> engine quits, I attribute the accident to the engine quitting. The NTSB
> works a bit differently. If the investigator thinks the pilot should
> have been able to safely land the aircraft despite the engine failure,
> the cause of the accident is listed as pilot error.
>
> So my "pilot failure" category does NOT take into account the difficulty
> of handling the aircraft in an emergency situation. While my stats may
> show the pilot error rate for the Velocity to be lower, the NTSB's may not.
>
> Ron Wanttaja

Great work and thanks!

[Alan Baker]

In article >,
"Morgans" > wrote:

> "Alan Baker" > wrote
>
> > Right. But trying to take moments about a centre of drag that is
> > changing because of the very thing causing you to take the moments in
> > the first place is a recipe for madness.
> >
> > Just take them about the centre of mass!
>
> It matters not what you take the moments from, as long as it is from a
> stationary reference on the plane.

That much at least is true.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Peter Dohm]

"Ron Wanttaja" > wrote in message
...
> Gezellig wrote:
>> On Thu, 30 Oct 2008 19:38:03 -0700, Ron Wanttaja wrote:
>>>> This is the safest homebuilt IMO.(VariEze ). The canard makes it
>>>> foolproof.
>>> If that were the case, the Velocity would have a better safety record
>>> than the Lancair family. Based on my statistics from 1999 through 2006,
>>> it doesn't... the Velocity has about a 20% higher accident rate. In
>>> fact, the Velocity has a rate almost three TIMES higher that of the RV
>>> fleet. Which isn't doesn't use canards, either.
>>
>> Ron, do you judge from this that the Velocity (or the pusher/canards in
>> general) have basic design issues (such as the Lancair's low speed
>> regime history)?
>
> It's funny you should ask, because that was one of the questions I was
> hoping to answer when I got into homebuilt accident analysis about five
> years ago.
>
> Still haven't answered it.
>
> There are so many factors involved that I could spend years of full-time
> work trying to dig them out. The fleet size of the Velocity is still
> relatively low, for example, and as well all know, one or two extra
> accidents can cause a disproportionate change.
>
> I dug a bit deeper into my database, and extracted the accident-cause data
> for about 20 homebuilt types. As I mentioned on my last post, the
> Velocity has an accident rate generally higher than most. Yet, the
> Velocity had nearly the LOWEST "stick and rudder error" rate. About 43%
> of RV-6 accidents involved the pilot's handling of the aircraft, vs. only
> 29% of the Velocities.
>
> HOWEVER (geeze, there's ALWAYS a "however" when you analyze accident
> statistics), the pilots in the Velocity accidents had about 25% more
> flight hours than those involved in RV accidents, and *four times* the
> hours than the average homebuilder involved in an accident.
>
> Lower rates because they're easier to fly...or because more-experienced
> pilots are flying them?
>
> My analysis method is a bit different from the NTSB's, too. I look for
> the first major event of the accident string, which means that if the
> engine quits, I attribute the accident to the engine quitting. The NTSB
> works a bit differently. If the investigator thinks the pilot should have
> been able to safely land the aircraft despite the engine failure, the
> cause of the accident is listed as pilot error.
>
> So my "pilot failure" category does NOT take into account the difficulty
> of handling the aircraft in an emergency situation. While my stats may
> show the pilot error rate for the Velocity to be lower, the NTSB's may
> not.
>
> Ron Wanttaja
>
>
Thanks for a lot of great work.

It seems to me to be very valuable to have statistics from both methods; in
order to make a more informed decision about building and testing an
experimental, and about flying any aircraft.

Peter

[BobR]

On Nov 1, 12:09*am, Alan Baker > wrote:
> In article
> >,
>
>
>
>
>
> *BobR > wrote:
> > On Oct 31, 2:59*pm, Alan Baker > wrote:
> > > In article
> > > >,
>
> > > *BobR > wrote:
> > > > On Oct 31, 2:09*pm, Alan Baker > wrote:
> > > > > In article
> > > > > >,
>
> > > > > *BobR > wrote:
> > > > > > On Oct 30, 5:12*pm, "Gregory Hall" > wrote:
> > > > > > > "Vaughn Simon" > wrote in message
>
> > > > > > ....
>
> > > > > > > > "Gregory Hall" > wrote in message
> > > > > > > ...
>
> > > > > > > >> It looks too much like an irresponsible, hot rod, stunt plane to
> > > > > > > >> me.
>
> > > > > > > > * Well, you sucked me in at first, so on a troll scale of
> > > > > > > > zero-to-10
> > > > > > > > you
> > > > > > > > rate at least a five. *How are things in France?
>
> > > > > > > > Vaughn
>
> > > > > > > France? *I don't live in France. I built and used to fly a Rotec
> > > > > > > Rally
> > > > > > > 2B
> > > > > > > many years ago. It was a tail dragger with a high wing and the
> > > > > > > motor
> > > > > > > was
> > > > > > > mounted atop the wind with a pusher prop.
>
> > > > > > > When I got it trimmed out correctly at cruise speeds I could lean
> > > > > > > forward in
> > > > > > > the seat to nose it down and lean back in the seat to nose it up.
> > > > > > > Even
> > > > > > > as
> > > > > > > well-balanced as it was at about half throttle, when the engine
> > > > > > > quit it
> > > > > > > would pitch up immediately and drastically because the high engine
> > > > > > > placement
> > > > > > > and pusher prop had enough leverage so that the proper trim at the
> > > > > > > tail
> > > > > > > counteracted the nose down force of the engine and prop. If you
> > > > > > > didn't
> > > > > > > immediately push the stick way forward when the engine quit it was
> > > > > > > a
> > > > > > > matter
> > > > > > > of seconds before it would nose up fast and stall and then you
> > > > > > > would
> > > > > > > have no
> > > > > > > control at all from the stick until it fell for a while and the
> > > > > > > nose
> > > > > > > dropped
> > > > > > > (thank god for that) so you could gain speed provided you had
> > > > > > > enough
> > > > > > > altitude to get control of it again. But it didn't glide too well
> > > > > > > being
> > > > > > > a
> > > > > > > single surface wing with wire bracing. Perhaps 2:1 glide ratio. But
> > > > > > > it
> > > > > > > was
> > > > > > > easy to land with no power but you had to come in hot and steep and
> > > > > > > at
> > > > > > > the
> > > > > > > last second pull back on the stick and flare it.
>
> > > > > > > It looks to me like the Legacy would act pretty much the same if
> > > > > > > the
> > > > > > > engine
> > > > > > > quit.
>
> > > > > > > --
> > > > > > > Gregory Hall
>
> > > > > > Oh for gawd sake, you are talking about two totally different designs
> > > > > > and the aerodynamics of the two are totally different. *The Lancair
> > > > > > is
> > > > > > NOT a pusher and the engine is mounted forward of the CG instead of
> > > > > > on
> > > > > > top of it. *When the engine quits it will not pitch upward. *The
> > > > > > plane
> > > > > > you flew had the engine well above the center of gravity with a
> > > > > > pusher
> > > > > > prop and as a result produced a force that pushed the nose of the
> > > > > > aircraft down. *The two planes would not act pretty much the same at
> > > > > > all. *The weight of the engine on the Legacy is forward of the CG and
> > > > > > as a result always pulling the nose of the plane down. *The counter
> > > > > > to
> > > > > > the nose down is the horizontal stabilizer and the elevator. *Look at
> > > > > > the angle of incedence on the Horizontal Stabilizer and you will find
> > > > > > a slight downward angle, not an upward angle as is common on the
> > > > > > wing. *This counteracts the force from the weight of the engine. *An
> > > > > > engine out condition will not have a significant effect on pitch
> > > > > > until
> > > > > > the airspeed changes and that will result in a nose down, not nose up
> > > > > > pull.
>
> > > > > The one thing not quite right is that there is no important difference
> > > > > between tractor vs. pusher configurations with respect to directional
> > > > > stability.
>
> > > > Not sure what you are replying to but I never said anything about
> > > > directional stability. *The discussion was regarding pitch forces..
>
> > > Which is essentially the same thing.
>
> > > Pusher or puller doesn't affect pitch forces. What affects pitch forces
> > > is the length of the moment arm between the centre of mass and the
> > > thrust line.
>
> > > > > Like some of the early rocket designers (e.g. Goddard), you are falling
> > > > > into the fallacy that somehow pulling is more stable than pushing.. This
> > > > > is not so.
>
> > > > > --
> > > > > Alan Baker
> > > > > Vancouver, British Columbia
> > > > > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted
> > > > > text -
>
> > > > > - Show quoted text -
>
> > > --
> > > Alan Baker
> > > Vancouver, British Columbia
> > > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted
> > > text -
>
> > > - Show quoted text -
>
> > Again Alan, I never indicated any issue with pusher vs tractor. *The
> > layout of the two planes being discussed is totally different. *One
> > involved a tractor configuration with the thrust line being very near
> > the vertical center of gravity. *The second involved an plane with the
> > engine mounted on a pylon with a thrust line well above the vertical
> > center of gravity. *This configuration, rather it be a tractor or
> > pusher will induce nose down forces that must be countered by the
> > horizontal stabilizer with an upward force. *This is contrary to the
> > standard configuration which requires a downward force to counter the
> > weight of the engine. *The post I was replying to was trying to link
> > the characteristic of the pylon mounted configuration to the Legacy.
>
> Sorry, man, but you made specific reference to the plane being a pusher
> as if it was a relevant factor:
>
> "The Lancair is NOT a pusher and the engine is mounted forward of the CG
> instead of on top of it. *When the engine quits it will not pitch
> upward. *The plane you flew had the engine well above the center of
> gravity with a pusher prop and as a result produced a force that pushed
> the nose of the aircraft down."
>
> When you include extraneous details, you make the essence of the
> situation harder to glean.
>
> And you're doing it again. You're conflating thrust line induced pitch
> changes with weight of engine. One is changing, one is constant.
>
> The only part that you had to talk about was the fact that the thrust
> line was significantly above the centre of mass. The weight of the
> engine doesn't matter (in an aircraft that has it's centre of gravity
> appropriately located), nor does pusher vs. puller.
>
> --
> Alan Baker
> Vancouver, British Columbia
> <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted text -
>
> - Show quoted text -

Well excuse the holy hell out of me for not phrasing things the way
you want it. My references were based on the specifics of the two
planes involved in the discussion and if you can't gleem that fact
from it, too ****ing bad.

[Alan Baker]

In article
>,
BobR > wrote:

> On Nov 1, 12:09*am, Alan Baker > wrote:
> > In article
> > >,
> >
> >
> >
> >
> >
> > *BobR > wrote:
> > > On Oct 31, 2:59*pm, Alan Baker > wrote:
> > > > In article
> > > > >,
> >
> > > > *BobR > wrote:
> > > > > On Oct 31, 2:09*pm, Alan Baker > wrote:
> > > > > > In article
> > > > > > >,
> >
> > > > > > *BobR > wrote:
> > > > > > > On Oct 30, 5:12*pm, "Gregory Hall" > wrote:
> > > > > > > > "Vaughn Simon" > wrote in
> > > > > > > > message
> >
> > > > > > > ...
> >
> > > > > > > > > "Gregory Hall" > wrote in message
> > > > > > > > ...
> >
> > > > > > > > >> It looks too much like an irresponsible, hot rod, stunt
> > > > > > > > >> plane to
> > > > > > > > >> me.
> >
> > > > > > > > > * Well, you sucked me in at first, so on a troll scale of
> > > > > > > > > zero-to-10
> > > > > > > > > you
> > > > > > > > > rate at least a five. *How are things in France?
> >
> > > > > > > > > Vaughn
> >
> > > > > > > > France? *I don't live in France. I built and used to fly a
> > > > > > > > Rotec
> > > > > > > > Rally
> > > > > > > > 2B
> > > > > > > > many years ago. It was a tail dragger with a high wing and the
> > > > > > > > motor
> > > > > > > > was
> > > > > > > > mounted atop the wind with a pusher prop.
> >
> > > > > > > > When I got it trimmed out correctly at cruise speeds I could
> > > > > > > > lean
> > > > > > > > forward in
> > > > > > > > the seat to nose it down and lean back in the seat to nose it
> > > > > > > > up.
> > > > > > > > Even
> > > > > > > > as
> > > > > > > > well-balanced as it was at about half throttle, when the engine
> > > > > > > > quit it
> > > > > > > > would pitch up immediately and drastically because the high
> > > > > > > > engine
> > > > > > > > placement
> > > > > > > > and pusher prop had enough leverage so that the proper trim at
> > > > > > > > the
> > > > > > > > tail
> > > > > > > > counteracted the nose down force of the engine and prop. If you
> > > > > > > > didn't
> > > > > > > > immediately push the stick way forward when the engine quit it
> > > > > > > > was
> > > > > > > > a
> > > > > > > > matter
> > > > > > > > of seconds before it would nose up fast and stall and then you
> > > > > > > > would
> > > > > > > > have no
> > > > > > > > control at all from the stick until it fell for a while and the
> > > > > > > > nose
> > > > > > > > dropped
> > > > > > > > (thank god for that) so you could gain speed provided you had
> > > > > > > > enough
> > > > > > > > altitude to get control of it again. But it didn't glide too
> > > > > > > > well
> > > > > > > > being
> > > > > > > > a
> > > > > > > > single surface wing with wire bracing. Perhaps 2:1 glide ratio.
> > > > > > > > But
> > > > > > > > it
> > > > > > > > was
> > > > > > > > easy to land with no power but you had to come in hot and steep
> > > > > > > > and
> > > > > > > > at
> > > > > > > > the
> > > > > > > > last second pull back on the stick and flare it.
> >
> > > > > > > > It looks to me like the Legacy would act pretty much the same
> > > > > > > > if
> > > > > > > > the
> > > > > > > > engine
> > > > > > > > quit.
> >
> > > > > > > > --
> > > > > > > > Gregory Hall
> >
> > > > > > > Oh for gawd sake, you are talking about two totally different
> > > > > > > designs
> > > > > > > and the aerodynamics of the two are totally different. *The
> > > > > > > Lancair
> > > > > > > is
> > > > > > > NOT a pusher and the engine is mounted forward of the CG instead
> > > > > > > of
> > > > > > > on
> > > > > > > top of it. *When the engine quits it will not pitch upward. *The
> > > > > > > plane
> > > > > > > you flew had the engine well above the center of gravity with a
> > > > > > > pusher
> > > > > > > prop and as a result produced a force that pushed the nose of the
> > > > > > > aircraft down. *The two planes would not act pretty much the same
> > > > > > > at
> > > > > > > all. *The weight of the engine on the Legacy is forward of the CG
> > > > > > > and
> > > > > > > as a result always pulling the nose of the plane down. *The
> > > > > > > counter
> > > > > > > to
> > > > > > > the nose down is the horizontal stabilizer and the elevator.
> > > > > > > *Look at
> > > > > > > the angle of incedence on the Horizontal Stabilizer and you will
> > > > > > > find
> > > > > > > a slight downward angle, not an upward angle as is common on the
> > > > > > > wing. *This counteracts the force from the weight of the engine.
> > > > > > > *An
> > > > > > > engine out condition will not have a significant effect on pitch
> > > > > > > until
> > > > > > > the airspeed changes and that will result in a nose down, not
> > > > > > > nose up
> > > > > > > pull.
> >
> > > > > > The one thing not quite right is that there is no important
> > > > > > difference
> > > > > > between tractor vs. pusher configurations with respect to
> > > > > > directional
> > > > > > stability.
> >
> > > > > Not sure what you are replying to but I never said anything about
> > > > > directional stability. *The discussion was regarding pitch forces.
> >
> > > > Which is essentially the same thing.
> >
> > > > Pusher or puller doesn't affect pitch forces. What affects pitch forces
> > > > is the length of the moment arm between the centre of mass and the
> > > > thrust line.
> >
> > > > > > Like some of the early rocket designers (e.g. Goddard), you are
> > > > > > falling
> > > > > > into the fallacy that somehow pulling is more stable than pushing.
> > > > > > This
> > > > > > is not so.
> >
> > > > > > --
> > > > > > Alan Baker
> > > > > > Vancouver, British Columbia
> > > > > > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide
> > > > > > quoted
> > > > > > text -
> >
> > > > > > - Show quoted text -
> >
> > > > --
> > > > Alan Baker
> > > > Vancouver, British Columbia
> > > > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted
> > > > text -
> >
> > > > - Show quoted text -
> >
> > > Again Alan, I never indicated any issue with pusher vs tractor. *The
> > > layout of the two planes being discussed is totally different. *One
> > > involved a tractor configuration with the thrust line being very near
> > > the vertical center of gravity. *The second involved an plane with the
> > > engine mounted on a pylon with a thrust line well above the vertical
> > > center of gravity. *This configuration, rather it be a tractor or
> > > pusher will induce nose down forces that must be countered by the
> > > horizontal stabilizer with an upward force. *This is contrary to the
> > > standard configuration which requires a downward force to counter the
> > > weight of the engine. *The post I was replying to was trying to link
> > > the characteristic of the pylon mounted configuration to the Legacy.
> >
> > Sorry, man, but you made specific reference to the plane being a pusher
> > as if it was a relevant factor:
> >
> > "The Lancair is NOT a pusher and the engine is mounted forward of the CG
> > instead of on top of it. *When the engine quits it will not pitch
> > upward. *The plane you flew had the engine well above the center of
> > gravity with a pusher prop and as a result produced a force that pushed
> > the nose of the aircraft down."
> >
> > When you include extraneous details, you make the essence of the
> > situation harder to glean.
> >
> > And you're doing it again. You're conflating thrust line induced pitch
> > changes with weight of engine. One is changing, one is constant.
> >
> > The only part that you had to talk about was the fact that the thrust
> > line was significantly above the centre of mass. The weight of the
> > engine doesn't matter (in an aircraft that has it's centre of gravity
> > appropriately located), nor does pusher vs. puller.
> >
> > --
> > Alan Baker
> > Vancouver, British Columbia
> > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted
> > text -
> >
> > - Show quoted text -
>
> Well excuse the holy hell out of me for not phrasing things the way
> you want it. My references were based on the specifics of the two
> planes involved in the discussion and if you can't gleem that fact
> from it, too ****ing bad.

Trying to retcon your comments and say that such and such wasn't what
you meant would work better if you...

....ACTUALLY SHOWED YOU UNDERSTOOD WHAT YOU'RE TALKING ABOUT...

....in your next post.

You, OTOH, showed you still didn't get it and now you're getting ****y.

And the word your tiny little mind was scratching for was "glean".

Always happy to help the ignorant.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[BobR]

On Nov 1, 9:40*pm, Alan Baker > wrote:
> In article
> >,
>
>
>
>
>
> *BobR > wrote:
> > On Nov 1, 12:09*am, Alan Baker > wrote:
> > > In article
> > > >,
>
> > > *BobR > wrote:
> > > > On Oct 31, 2:59*pm, Alan Baker > wrote:
> > > > > In article
> > > > > >,
>
> > > > > *BobR > wrote:
> > > > > > On Oct 31, 2:09*pm, Alan Baker > wrote:
> > > > > > > In article
> > > > > > > >,
>
> > > > > > > *BobR > wrote:
> > > > > > > > On Oct 30, 5:12*pm, "Gregory Hall" > wrote:
> > > > > > > > > "Vaughn Simon" > wrote in
> > > > > > > > > message
>
> > > > > > > > ...
>
> > > > > > > > > > "Gregory Hall" > wrote in message
> > > > > > > > > ...
>
> > > > > > > > > >> It looks too much like an irresponsible, hot rod, stunt
> > > > > > > > > >> plane to
> > > > > > > > > >> me.
>
> > > > > > > > > > * Well, you sucked me in at first, so on a troll scale of
> > > > > > > > > > zero-to-10
> > > > > > > > > > you
> > > > > > > > > > rate at least a five. *How are things in France?
>
> > > > > > > > > > Vaughn
>
> > > > > > > > > France? *I don't live in France. I built and used to fly a
> > > > > > > > > Rotec
> > > > > > > > > Rally
> > > > > > > > > 2B
> > > > > > > > > many years ago. It was a tail dragger with a high wing and the
> > > > > > > > > motor
> > > > > > > > > was
> > > > > > > > > mounted atop the wind with a pusher prop.
>
> > > > > > > > > When I got it trimmed out correctly at cruise speeds I could
> > > > > > > > > lean
> > > > > > > > > forward in
> > > > > > > > > the seat to nose it down and lean back in the seat to nose it
> > > > > > > > > up.
> > > > > > > > > Even
> > > > > > > > > as
> > > > > > > > > well-balanced as it was at about half throttle, when the engine
> > > > > > > > > quit it
> > > > > > > > > would pitch up immediately and drastically because the high
> > > > > > > > > engine
> > > > > > > > > placement
> > > > > > > > > and pusher prop had enough leverage so that the proper trim at
> > > > > > > > > the
> > > > > > > > > tail
> > > > > > > > > counteracted the nose down force of the engine and prop. If you
> > > > > > > > > didn't
> > > > > > > > > immediately push the stick way forward when the engine quit it
> > > > > > > > > was
> > > > > > > > > a
> > > > > > > > > matter
> > > > > > > > > of seconds before it would nose up fast and stall and then you
> > > > > > > > > would
> > > > > > > > > have no
> > > > > > > > > control at all from the stick until it fell for a while and the
> > > > > > > > > nose
> > > > > > > > > dropped
> > > > > > > > > (thank god for that) so you could gain speed provided you had
> > > > > > > > > enough
> > > > > > > > > altitude to get control of it again. But it didn't glide too
> > > > > > > > > well
> > > > > > > > > being
> > > > > > > > > a
> > > > > > > > > single surface wing with wire bracing. Perhaps 2:1 glide ratio.
> > > > > > > > > But
> > > > > > > > > it
> > > > > > > > > was
> > > > > > > > > easy to land with no power but you had to come in hot and steep
> > > > > > > > > and
> > > > > > > > > at
> > > > > > > > > the
> > > > > > > > > last second pull back on the stick and flare it.
>
> > > > > > > > > It looks to me like the Legacy would act pretty much the same
> > > > > > > > > if
> > > > > > > > > the
> > > > > > > > > engine
> > > > > > > > > quit.
>
> > > > > > > > > --
> > > > > > > > > Gregory Hall
>
> > > > > > > > Oh for gawd sake, you are talking about two totally different
> > > > > > > > designs
> > > > > > > > and the aerodynamics of the two are totally different. *The
> > > > > > > > Lancair
> > > > > > > > is
> > > > > > > > NOT a pusher and the engine is mounted forward of the CG instead
> > > > > > > > of
> > > > > > > > on
> > > > > > > > top of it. *When the engine quits it will not pitch upward. *The
> > > > > > > > plane
> > > > > > > > you flew had the engine well above the center of gravity with a
> > > > > > > > pusher
> > > > > > > > prop and as a result produced a force that pushed the nose of the
> > > > > > > > aircraft down. *The two planes would not act pretty much the same
> > > > > > > > at
> > > > > > > > all. *The weight of the engine on the Legacy is forward of the CG
> > > > > > > > and
> > > > > > > > as a result always pulling the nose of the plane down. *The
> > > > > > > > counter
> > > > > > > > to
> > > > > > > > the nose down is the horizontal stabilizer and the elevator..
> > > > > > > > *Look at
> > > > > > > > the angle of incedence on the Horizontal Stabilizer and you will
> > > > > > > > find
> > > > > > > > a slight downward angle, not an upward angle as is common on the
> > > > > > > > wing. *This counteracts the force from the weight of the engine.
> > > > > > > > *An
> > > > > > > > engine out condition will not have a significant effect on pitch
> > > > > > > > until
> > > > > > > > the airspeed changes and that will result in a nose down, not
> > > > > > > > nose up
> > > > > > > > pull.
>
> > > > > > > The one thing not quite right is that there is no important
> > > > > > > difference
> > > > > > > between tractor vs. pusher configurations with respect to
> > > > > > > directional
> > > > > > > stability.
>
> > > > > > Not sure what you are replying to but I never said anything about
> > > > > > directional stability. *The discussion was regarding pitch forces.
>
> > > > > Which is essentially the same thing.
>
> > > > > Pusher or puller doesn't affect pitch forces. What affects pitch forces
> > > > > is the length of the moment arm between the centre of mass and the
> > > > > thrust line.
>
> > > > > > > Like some of the early rocket designers (e.g. Goddard), you are
> > > > > > > falling
> > > > > > > into the fallacy that somehow pulling is more stable than pushing.
> > > > > > > This
> > > > > > > is not so.
>
> > > > > > > --
> > > > > > > Alan Baker
> > > > > > > Vancouver, British Columbia
> > > > > > > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide
> > > > > > > quoted
> > > > > > > text -
>
> > > > > > > - Show quoted text -
>
> > > > > --
> > > > > Alan Baker
> > > > > Vancouver, British Columbia
> > > > > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted
> > > > > text -
>
> > > > > - Show quoted text -
>
> > > > Again Alan, I never indicated any issue with pusher vs tractor. *The
> > > > layout of the two planes being discussed is totally different. *One
> > > > involved a tractor configuration with the thrust line being very near
> > > > the vertical center of gravity. *The second involved an plane with the
> > > > engine mounted on a pylon with a thrust line well above the vertical
> > > > center of gravity. *This configuration, rather it be a tractor or
> > > > pusher will induce nose down forces that must be countered by the
> > > > horizontal stabilizer with an upward force. *This is contrary to the
> > > > standard configuration which requires a downward force to counter the
> > > > weight of the engine. *The post I was replying to was trying to link
> > > > the characteristic of the pylon mounted configuration to the Legacy..
>
> > > Sorry, man, but you made specific reference to the plane being a pusher
> > > as if it was a relevant factor:
>
> > > "The Lancair is NOT a pusher and the engine is mounted forward of the CG
> > > instead of on top of it. *When the engine quits it will not pitch
> > > upward. *The plane you flew had the engine well above the center of
> > > gravity with a pusher prop and as a result produced a force that pushed
> > > the nose of the aircraft down."
>
> > > When you include extraneous details, you make the essence of the
> > > situation harder to glean.
>
> > > And you're doing it again. You're conflating thrust line induced pitch
> > > changes with weight of engine. One is changing, one is constant.
>
> > > The only part that you had to talk about was the fact that the thrust
> > > line was significantly above the centre of mass. The weight of the
> > > engine doesn't matter (in an aircraft that has it's centre of gravity
> > > appropriately located), nor does pusher vs. puller.
>
> > > --
> > > Alan Baker
> > > Vancouver, British Columbia
> > > <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted
> > > text -
>
> > > - Show quoted text -
>
> > Well excuse the holy hell out of me for not phrasing things the way
> > you want it. *My references were based on the specifics of the two
> > planes involved in the discussion and if you can't gleem that fact
> > from it, too ****ing bad.
>
> Trying to retcon your comments and say that such and such wasn't what
> you meant would work better if you...
>

I said what I ment but I can't help that you read into it something
else.

> ...ACTUALLY SHOWED YOU UNDERSTOOD WHAT YOU'RE TALKING ABOUT...
>

I knew exactly what I was talking about but again, you read something
into it beyond what I said. That part is your problem not mine.

> ...in your next post.
>
> You, OTOH, showed you still didn't get it and now you're getting ****y.
>

I am getting very tired of your arrogant attitude that ONLY YOU
understand.

> And the word your tiny little mind was scratching for was "glean".
>

Sorry but my typing isn't always the greatest and once again, your
arrogance shows in thinking you are the only smart one in the group.

> Always happy to help the ignorant.
>

Gee, so nice of you to come down from that tower you put yourself into
and mingle with us common folk.


> --
> Alan Baker
> Vancouver, British Columbia
> <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted text -
>
> - Show quoted text -

[Alan Baker]

In article
>,
BobR > wrote:

<snip>

> > > > > > > > > > >> It looks too much like an irresponsible, hot rod, stunt
> > > > > > > > > > >> plane to
> > > > > > > > > > >> me.
> >
> > > > > > > > > > > * Well, you sucked me in at first, so on a troll scale of
> > > > > > > > > > > zero-to-10
> > > > > > > > > > > you
> > > > > > > > > > > rate at least a five. *How are things in France?
> >
> > > > > > > > > > > Vaughn
> >
> > > > > > > > > > France? *I don't live in France. I built and used to fly a
> > > > > > > > > > Rotec
> > > > > > > > > > Rally
> > > > > > > > > > 2B
> > > > > > > > > > many years ago. It was a tail dragger with a high wing and
> > > > > > > > > > the
> > > > > > > > > > motor
> > > > > > > > > > was
> > > > > > > > > > mounted atop the wind with a pusher prop.
> >
> > > > > > > > > > When I got it trimmed out correctly at cruise speeds I
> > > > > > > > > > could
> > > > > > > > > > lean
> > > > > > > > > > forward in
> > > > > > > > > > the seat to nose it down and lean back in the seat to nose
> > > > > > > > > > it
> > > > > > > > > > up.
> > > > > > > > > > Even
> > > > > > > > > > as
> > > > > > > > > > well-balanced as it was at about half throttle, when the
> > > > > > > > > > engine
> > > > > > > > > > quit it
> > > > > > > > > > would pitch up immediately and drastically because the high
> > > > > > > > > > engine
> > > > > > > > > > placement
> > > > > > > > > > and pusher prop had enough leverage so that the proper trim
> > > > > > > > > > at
> > > > > > > > > > the
> > > > > > > > > > tail
> > > > > > > > > > counteracted the nose down force of the engine and prop. If
> > > > > > > > > > you
> > > > > > > > > > didn't
> > > > > > > > > > immediately push the stick way forward when the engine quit
> > > > > > > > > > it
> > > > > > > > > > was
> > > > > > > > > > a
> > > > > > > > > > matter
> > > > > > > > > > of seconds before it would nose up fast and stall and then
> > > > > > > > > > you
> > > > > > > > > > would
> > > > > > > > > > have no
> > > > > > > > > > control at all from the stick until it fell for a while and
> > > > > > > > > > the
> > > > > > > > > > nose
> > > > > > > > > > dropped
> > > > > > > > > > (thank god for that) so you could gain speed provided you
> > > > > > > > > > had
> > > > > > > > > > enough
> > > > > > > > > > altitude to get control of it again. But it didn't glide
> > > > > > > > > > too
> > > > > > > > > > well
> > > > > > > > > > being
> > > > > > > > > > a
> > > > > > > > > > single surface wing with wire bracing. Perhaps 2:1 glide
> > > > > > > > > > ratio.
> > > > > > > > > > But
> > > > > > > > > > it
> > > > > > > > > > was
> > > > > > > > > > easy to land with no power but you had to come in hot and
> > > > > > > > > > steep
> > > > > > > > > > and
> > > > > > > > > > at
> > > > > > > > > > the
> > > > > > > > > > last second pull back on the stick and flare it.
> >
> > > > > > > > > > It looks to me like the Legacy would act pretty much the
> > > > > > > > > > same
> > > > > > > > > > if
> > > > > > > > > > the
> > > > > > > > > > engine
> > > > > > > > > > quit.
> >
> > > > > > > > > > --
> > > > > > > > > > Gregory Hall
> >
> > > > > > > > > Oh for gawd sake, you are talking about two totally different
> > > > > > > > > designs
> > > > > > > > > and the aerodynamics of the two are totally different. *The
> > > > > > > > > Lancair
> > > > > > > > > is
> > > > > > > > > NOT a pusher and the engine is mounted forward of the CG
> > > > > > > > > instead
> > > > > > > > > of
> > > > > > > > > on
> > > > > > > > > top of it. *When the engine quits it will not pitch upward.
> > > > > > > > > *The
> > > > > > > > > plane
> > > > > > > > > you flew had the engine well above the center of gravity with
> > > > > > > > > a
> > > > > > > > > pusher
> > > > > > > > > prop and as a result produced a force that pushed the nose of
> > > > > > > > > the
> > > > > > > > > aircraft down. *The two planes would not act pretty much the
> > > > > > > > > same
> > > > > > > > > at
> > > > > > > > > all. *The weight of the engine on the Legacy is forward of
> > > > > > > > > the CG
> > > > > > > > > and
> > > > > > > > > as a result always pulling the nose of the plane down. *The
> > > > > > > > > counter
> > > > > > > > > to
> > > > > > > > > the nose down is the horizontal stabilizer and the elevator.
> > > > > > > > > *Look at
> > > > > > > > > the angle of incedence on the Horizontal Stabilizer and you
> > > > > > > > > will
> > > > > > > > > find
> > > > > > > > > a slight downward angle, not an upward angle as is common on
> > > > > > > > > the
> > > > > > > > > wing. *This counteracts the force from the weight of the
> > > > > > > > > engine.
> > > > > > > > > *An
> > > > > > > > > engine out condition will not have a significant effect on
> > > > > > > > > pitch
> > > > > > > > > until
> > > > > > > > > the airspeed changes and that will result in a nose down, not
> > > > > > > > > nose up
> > > > > > > > > pull.
> >
> > > > > > > > The one thing not quite right is that there is no important
> > > > > > > > difference
> > > > > > > > between tractor vs. pusher configurations with respect to
> > > > > > > > directional
> > > > > > > > stability.
> >
> > > > > > > Not sure what you are replying to but I never said anything about
> > > > > > > directional stability. *The discussion was regarding pitch
> > > > > > > forces.
> >
> > > > > > Which is essentially the same thing.
> >
> > > > > > Pusher or puller doesn't affect pitch forces. What affects pitch
> > > > > > forces
> > > > > > is the length of the moment arm between the centre of mass and the
> > > > > > thrust line.
> >
> > > > > > > > Like some of the early rocket designers (e.g. Goddard), you are
> > > > > > > > falling
> > > > > > > > into the fallacy that somehow pulling is more stable than
> > > > > > > > pushing.
> > > > > > > > This
> > > > > > > > is not so.
> >
> > > > > > - Show quoted text -
> >
> > > > > Again Alan, I never indicated any issue with pusher vs tractor. *The
> > > > > layout of the two planes being discussed is totally different. *One
> > > > > involved a tractor configuration with the thrust line being very near
> > > > > the vertical center of gravity. *The second involved an plane with
> > > > > the
> > > > > engine mounted on a pylon with a thrust line well above the vertical
> > > > > center of gravity. *This configuration, rather it be a tractor or
> > > > > pusher will induce nose down forces that must be countered by the
> > > > > horizontal stabilizer with an upward force. *This is contrary to the
> > > > > standard configuration which requires a downward force to counter the
> > > > > weight of the engine. *The post I was replying to was trying to link
> > > > > the characteristic of the pylon mounted configuration to the Legacy.
> >
> > > > Sorry, man, but you made specific reference to the plane being a pusher
> > > > as if it was a relevant factor:
> >
> > > > "The Lancair is NOT a pusher and the engine is mounted forward of the
> > > > CG
> > > > instead of on top of it. *When the engine quits it will not pitch
> > > > upward. *The plane you flew had the engine well above the center of
> > > > gravity with a pusher prop and as a result produced a force that pushed
> > > > the nose of the aircraft down."
> >
> > > > When you include extraneous details, you make the essence of the
> > > > situation harder to glean.
> >
> > > > And you're doing it again. You're conflating thrust line induced pitch
> > > > changes with weight of engine. One is changing, one is constant.
> >
> > > > The only part that you had to talk about was the fact that the thrust
> > > > line was significantly above the centre of mass. The weight of the
> > > > engine doesn't matter (in an aircraft that has it's centre of gravity
> > > > appropriately located), nor does pusher vs. puller.
> >
> > > > - Show quoted text -
> >
> > > Well excuse the holy hell out of me for not phrasing things the way
> > > you want it. *My references were based on the specifics of the two
> > > planes involved in the discussion and if you can't gleem that fact
> > > from it, too ****ing bad.
> >
> > Trying to retcon your comments and say that such and such wasn't what
> > you meant would work better if you...
> >
>
> I said what I ment but I can't help that you read into it something
> else.

And you made the fact that the aircraft was a pusher an issue.

You were wrong. Deal with it.

>
> > ...ACTUALLY SHOWED YOU UNDERSTOOD WHAT YOU'RE TALKING ABOUT...
> >
>
> I knew exactly what I was talking about but again, you read something
> into it beyond what I said. That part is your problem not mine.

Nope. Because the weight of an engine has precisely the same influence
on the aircraft at all times, operating or not.

>
> > ...in your next post.
> >
> > You, OTOH, showed you still didn't get it and now you're getting ****y.
> >
>
> I am getting very tired of your arrogant attitude that ONLY YOU
> understand.

Not "only me", just -- quite obviously -- not you.

>
> > And the word your tiny little mind was scratching for was "glean".
> >
>
> Sorry but my typing isn't always the greatest and once again, your
> arrogance shows in thinking you are the only smart one in the group.

Sorry, (and note the correct use of the comma, BTW) but the error wasn't
a typo, and you can't retcon it into one.


>
> > Always happy to help the ignorant.
> >
>
> Gee, so nice of you to come down from that tower you put yourself into
> and mingle with us common folk.

Hey...

You're more common than most.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Alan Baker]

In article >,
Bryan Martin > wrote:

> In article
> >,
> BobR > wrote:
>
> > I said what I ment but I can't help that you read into it something
> > else.
>
> I for one understood exactly what you meant, but then, I also read the
> post that you were replying to. Apparently, Alan didn't bother to do
> that. On the other hand, he is from a foreign country, maybe there's
> some language barrier issues involved. :)

I understood what he meant, and it included the idea that the pusher vs
tractor element played a role.

"The Lancair is NOT a pusher..."

He's the one who included a completely irrelevant fact as his very first
discriminator.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[cavelamb himself[_4_]]

If I may save Jim the trouble....


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[BobR]

On Nov 2, 5:56*pm, Alan Baker > wrote:
> In article
> >,
>
> *BobR > wrote:
>
> <snip>
>
>
>
>
>
> > > > > > > > > > > >> It looks too much like an irresponsible, hot rod, stunt
> > > > > > > > > > > >> plane to
> > > > > > > > > > > >> me.
>
> > > > > > > > > > > > * Well, you sucked me in at first, so on a troll scale of
> > > > > > > > > > > > zero-to-10
> > > > > > > > > > > > you
> > > > > > > > > > > > rate at least a five. *How are things in France?
>
> > > > > > > > > > > > Vaughn
>
> > > > > > > > > > > France? *I don't live in France. I built and used to fly a
> > > > > > > > > > > Rotec
> > > > > > > > > > > Rally
> > > > > > > > > > > 2B
> > > > > > > > > > > many years ago. It was a tail dragger with a high wing and
> > > > > > > > > > > the
> > > > > > > > > > > motor
> > > > > > > > > > > was
> > > > > > > > > > > mounted atop the wind with a pusher prop.
>
> > > > > > > > > > > When I got it trimmed out correctly at cruise speeds I
> > > > > > > > > > > could
> > > > > > > > > > > lean
> > > > > > > > > > > forward in
> > > > > > > > > > > the seat to nose it down and lean back in the seat to nose
> > > > > > > > > > > it
> > > > > > > > > > > up.
> > > > > > > > > > > Even
> > > > > > > > > > > as
> > > > > > > > > > > well-balanced as it was at about half throttle, when the
> > > > > > > > > > > engine
> > > > > > > > > > > quit it
> > > > > > > > > > > would pitch up immediately and drastically because the high
> > > > > > > > > > > engine
> > > > > > > > > > > placement
> > > > > > > > > > > and pusher prop had enough leverage so that the proper trim
> > > > > > > > > > > at
> > > > > > > > > > > the
> > > > > > > > > > > tail
> > > > > > > > > > > counteracted the nose down force of the engine and prop. If
> > > > > > > > > > > you
> > > > > > > > > > > didn't
> > > > > > > > > > > immediately push the stick way forward when the engine quit
> > > > > > > > > > > it
> > > > > > > > > > > was
> > > > > > > > > > > a
> > > > > > > > > > > matter
> > > > > > > > > > > of seconds before it would nose up fast and stall and then
> > > > > > > > > > > you
> > > > > > > > > > > would
> > > > > > > > > > > have no
> > > > > > > > > > > control at all from the stick until it fell for a while and
> > > > > > > > > > > the
> > > > > > > > > > > nose
> > > > > > > > > > > dropped
> > > > > > > > > > > (thank god for that) so you could gain speed provided you
> > > > > > > > > > > had
> > > > > > > > > > > enough
> > > > > > > > > > > altitude to get control of it again. But it didn't glide
> > > > > > > > > > > too
> > > > > > > > > > > well
> > > > > > > > > > > being
> > > > > > > > > > > a
> > > > > > > > > > > single surface wing with wire bracing. Perhaps 2:1 glide
> > > > > > > > > > > ratio.
> > > > > > > > > > > But
> > > > > > > > > > > it
> > > > > > > > > > > was
> > > > > > > > > > > easy to land with no power but you had to come in hot and
> > > > > > > > > > > steep
> > > > > > > > > > > and
> > > > > > > > > > > at
> > > > > > > > > > > the
> > > > > > > > > > > last second pull back on the stick and flare it.
>
> > > > > > > > > > > It looks to me like the Legacy would act pretty much the
> > > > > > > > > > > same
> > > > > > > > > > > if
> > > > > > > > > > > the
> > > > > > > > > > > engine
> > > > > > > > > > > quit.
>
> > > > > > > > > > > --
> > > > > > > > > > > Gregory Hall
>
> > > > > > > > > > Oh for gawd sake, you are talking about two totally different
> > > > > > > > > > designs
> > > > > > > > > > and the aerodynamics of the two are totally different. *The
> > > > > > > > > > Lancair
> > > > > > > > > > is
> > > > > > > > > > NOT a pusher and the engine is mounted forward of the CG
> > > > > > > > > > instead
> > > > > > > > > > of
> > > > > > > > > > on
> > > > > > > > > > top of it. *When the engine quits it will not pitch upward.
> > > > > > > > > > *The
> > > > > > > > > > plane
> > > > > > > > > > you flew had the engine well above the center of gravity with
> > > > > > > > > > a
> > > > > > > > > > pusher
> > > > > > > > > > prop and as a result produced a force that pushed the nose of
> > > > > > > > > > the
> > > > > > > > > > aircraft down. *The two planes would not act pretty much the
> > > > > > > > > > same
> > > > > > > > > > at
> > > > > > > > > > all. *The weight of the engine on the Legacy is forward of
> > > > > > > > > > the CG
> > > > > > > > > > and
> > > > > > > > > > as a result always pulling the nose of the plane down. *The
> > > > > > > > > > counter
> > > > > > > > > > to
> > > > > > > > > > the nose down is the horizontal stabilizer and the elevator.
> > > > > > > > > > *Look at
> > > > > > > > > > the angle of incedence on the Horizontal Stabilizer and you
> > > > > > > > > > will
> > > > > > > > > > find
> > > > > > > > > > a slight downward angle, not an upward angle as is common on
> > > > > > > > > > the
> > > > > > > > > > wing. *This counteracts the force from the weight of the
> > > > > > > > > > engine.
> > > > > > > > > > *An
> > > > > > > > > > engine out condition will not have a significant effect on
> > > > > > > > > > pitch
> > > > > > > > > > until
> > > > > > > > > > the airspeed changes and that will result in a nose down, not
> > > > > > > > > > nose up
> > > > > > > > > > pull.
>
> > > > > > > > > The one thing not quite right is that there is no important
> > > > > > > > > difference
> > > > > > > > > between tractor vs. pusher configurations with respect to
> > > > > > > > > directional
> > > > > > > > > stability.
>
> > > > > > > > Not sure what you are replying to but I never said anything about
> > > > > > > > directional stability. *The discussion was regarding pitch
> > > > > > > > forces.
>
> > > > > > > Which is essentially the same thing.
>
> > > > > > > Pusher or puller doesn't affect pitch forces. What affects pitch
> > > > > > > forces
> > > > > > > is the length of the moment arm between the centre of mass and the
> > > > > > > thrust line.
>
> > > > > > > > > Like some of the early rocket designers (e.g. Goddard), you are
> > > > > > > > > falling
> > > > > > > > > into the fallacy that somehow pulling is more stable than
> > > > > > > > > pushing.
> > > > > > > > > This
> > > > > > > > > is not so.
>
> > > > > > > - Show quoted text -
>
> > > > > > Again Alan, I never indicated any issue with pusher vs tractor. *The
> > > > > > layout of the two planes being discussed is totally different. *One
> > > > > > involved a tractor configuration with the thrust line being very near
> > > > > > the vertical center of gravity. *The second involved an plane with
> > > > > > the
> > > > > > engine mounted on a pylon with a thrust line well above the vertical
> > > > > > center of gravity. *This configuration, rather it be a tractor or
> > > > > > pusher will induce nose down forces that must be countered by the
> > > > > > horizontal stabilizer with an upward force. *This is contrary to the
> > > > > > standard configuration which requires a downward force to counter the
> > > > > > weight of the engine. *The post I was replying to was trying to link
> > > > > > the characteristic of the pylon mounted configuration to the Legacy.
>
> > > > > Sorry, man, but you made specific reference to the plane being a pusher
> > > > > as if it was a relevant factor:
>
> > > > > "The Lancair is NOT a pusher and the engine is mounted forward of the
> > > > > CG
> > > > > instead of on top of it. *When the engine quits it will not pitch
> > > > > upward. *The plane you flew had the engine well above the center of
> > > > > gravity with a pusher prop and as a result produced a force that pushed
> > > > > the nose of the aircraft down."
>
> > > > > When you include extraneous details, you make the essence of the
> > > > > situation harder to glean.
>
> > > > > And you're doing it again. You're conflating thrust line induced pitch
> > > > > changes with weight of engine. One is changing, one is constant.
>
> > > > > The only part that you had to talk about was the fact that the thrust
> > > > > line was significantly above the centre of mass. The weight of the
> > > > > engine doesn't matter (in an aircraft that has it's centre of gravity
> > > > > appropriately located), nor does pusher vs. puller.
>
> > > > > - Show quoted text -
>
> > > > Well excuse the holy hell out of me for not phrasing things the way
> > > > you want it. *My references were based on the specifics of the two
> > > > planes involved in the discussion and if you can't gleem that fact
> > > > from it, too ****ing bad.
>
> > > Trying to retcon your comments and say that such and such wasn't what
> > > you meant would work better if you...
>
> > I said what I ment but I can't help that you read into it something
> > else.
>
> And you made the fact that the aircraft was a pusher an issue.
>
> You were wrong. Deal with it.
>

No, I never made the fact that the aircraft was a pusher into an
issue...YOU DID. I simply pointed out different design elements of
the two aircraft. You drew false conclusions from them and now try to
make a issue from them.
>
>
> > > ...ACTUALLY SHOWED YOU UNDERSTOOD WHAT YOU'RE TALKING ABOUT...
>
> > I knew exactly what I was talking about but again, you read something
> > into it beyond what I said. *That part is your problem not mine.
>
> Nope. Because the weight of an engine has precisely the same influence
> on the aircraft at all times, operating or not.
>
>

Gee do tell! Again you make false assumptions and then try and make
some point from it.

>
> > > ...in your next post.
>
> > > You, OTOH, showed you still didn't get it and now you're getting ****y.
>
> > I am getting very tired of your arrogant attitude that ONLY YOU
> > understand.
>
> Not "only me", just -- quite obviously -- not you.
>
>
>
> > > And the word your tiny little mind was scratching for was "glean".
>
> > Sorry but my typing isn't always the greatest and once again, your
> > arrogance shows in thinking you are the only smart one in the group.
>
> Sorry, (and note the correct use of the comma, BTW) but the error wasn't
> a typo, and you can't retcon it into one.
>

Yep, once again your arrogance rises to the occasion.

>
>
> > > Always happy to help the ignorant.
>
> > Gee, so nice of you to come down from that tower you put yourself into
> > and mingle with us common folk.
>
> Hey...
>
> You're more common than most.
>

And you are a lot more arrogant than most. Looking back through your
posts it was clear that you felt the necessity to correct just about
everyone. Guess that puts me in the good company of a lot of other
common folk.

[Alan Baker]

In article
>,
BobR > wrote:

> On Nov 2, 5:56*pm, Alan Baker > wrote:
> > In article
> > >,
> >
> > *BobR > wrote:
> >
> > <snip>
> >
> >
> >
> >
> >
<snip>

> > > > > > > > > > > Oh for gawd sake, you are talking about two totally
> > > > > > > > > > > different
> > > > > > > > > > > designs
> > > > > > > > > > > and the aerodynamics of the two are totally different.
> > > > > > > > > > > *The
> > > > > > > > > > > Lancair
> > > > > > > > > > > is
> > > > > > > > > > > NOT a pusher and the engine is mounted forward of the CG
> > > > > > > > > > > instead
> > > > > > > > > > > of
> > > > > > > > > > > on
> > > > > > > > > > > top of it. *When the engine quits it will not pitch
> > > > > > > > > > > upward.
> > > > > > > > > > > *The
> > > > > > > > > > > plane
> > > > > > > > > > > you flew had the engine well above the center of gravity
> > > > > > > > > > > with
> > > > > > > > > > > a
> > > > > > > > > > > pusher
> > > > > > > > > > > prop and as a result produced a force that pushed the
> > > > > > > > > > > nose of
> > > > > > > > > > > the
> > > > > > > > > > > aircraft down. *The two planes would not act pretty much
> > > > > > > > > > > the
> > > > > > > > > > > same
> > > > > > > > > > > at
> > > > > > > > > > > all. *The weight of the engine on the Legacy is forward
> > > > > > > > > > > of
> > > > > > > > > > > the CG
> > > > > > > > > > > and
> > > > > > > > > > > as a result always pulling the nose of the plane down.
> > > > > > > > > > > *The
> > > > > > > > > > > counter
> > > > > > > > > > > to
> > > > > > > > > > > the nose down is the horizontal stabilizer and the
> > > > > > > > > > > elevator.
> > > > > > > > > > > *Look at
> > > > > > > > > > > the angle of incedence on the Horizontal Stabilizer and
> > > > > > > > > > > you
> > > > > > > > > > > will
> > > > > > > > > > > find
> > > > > > > > > > > a slight downward angle, not an upward angle as is common
> > > > > > > > > > > on
> > > > > > > > > > > the
> > > > > > > > > > > wing. *This counteracts the force from the weight of the
> > > > > > > > > > > engine.
> > > > > > > > > > > *An
> > > > > > > > > > > engine out condition will not have a significant effect
> > > > > > > > > > > on
> > > > > > > > > > > pitch
> > > > > > > > > > > until
> > > > > > > > > > > the airspeed changes and that will result in a nose down,
> > > > > > > > > > > not
> > > > > > > > > > > nose up
> > > > > > > > > > > pull.
> >
> > > > > > > > > > The one thing not quite right is that there is no important
> > > > > > > > > > difference
> > > > > > > > > > between tractor vs. pusher configurations with respect to
> > > > > > > > > > directional
> > > > > > > > > > stability.
> >
> > > > > > > > > Not sure what you are replying to but I never said anything
> > > > > > > > > about
> > > > > > > > > directional stability. *The discussion was regarding pitch
> > > > > > > > > forces.
> >
> > > > > > > > Which is essentially the same thing.
> >
> > > > > > > > Pusher or puller doesn't affect pitch forces. What affects
> > > > > > > > pitch
> > > > > > > > forces
> > > > > > > > is the length of the moment arm between the centre of mass and
> > > > > > > > the
> > > > > > > > thrust line.
> >
> > > > > > > > > > Like some of the early rocket designers (e.g. Goddard), you
> > > > > > > > > > are
> > > > > > > > > > falling
> > > > > > > > > > into the fallacy that somehow pulling is more stable than
> > > > > > > > > > pushing.
> > > > > > > > > > This
> > > > > > > > > > is not so.
> >
> > > > > > > > - Show quoted text -
> >
> > > > > > > Again Alan, I never indicated any issue with pusher vs tractor.
> > > > > > > *The
> > > > > > > layout of the two planes being discussed is totally different.
> > > > > > > *One
> > > > > > > involved a tractor configuration with the thrust line being very
> > > > > > > near
> > > > > > > the vertical center of gravity. *The second involved an plane
> > > > > > > with
> > > > > > > the
> > > > > > > engine mounted on a pylon with a thrust line well above the
> > > > > > > vertical
> > > > > > > center of gravity. *This configuration, rather it be a tractor or
> > > > > > > pusher will induce nose down forces that must be countered by the
> > > > > > > horizontal stabilizer with an upward force. *This is contrary to
> > > > > > > the
> > > > > > > standard configuration which requires a downward force to counter
> > > > > > > the
> > > > > > > weight of the engine. *The post I was replying to was trying to
> > > > > > > link
> > > > > > > the characteristic of the pylon mounted configuration to the
> > > > > > > Legacy.
> >
> > > > > > Sorry, man, but you made specific reference to the plane being a
> > > > > > pusher
> > > > > > as if it was a relevant factor:
> >
> > > > > > "The Lancair is NOT a pusher and the engine is mounted forward of
> > > > > > the
> > > > > > CG
> > > > > > instead of on top of it. *When the engine quits it will not pitch
> > > > > > upward. *The plane you flew had the engine well above the center of
> > > > > > gravity with a pusher prop and as a result produced a force that
> > > > > > pushed
> > > > > > the nose of the aircraft down."
> >
> > > > > > When you include extraneous details, you make the essence of the
> > > > > > situation harder to glean.
> >
> > > > > > And you're doing it again. You're conflating thrust line induced
> > > > > > pitch
> > > > > > changes with weight of engine. One is changing, one is constant.
> >
> > > > > > The only part that you had to talk about was the fact that the
> > > > > > thrust
> > > > > > line was significantly above the centre of mass. The weight of the
> > > > > > engine doesn't matter (in an aircraft that has it's centre of
> > > > > > gravity
> > > > > > appropriately located), nor does pusher vs. puller.
> >
> > > > > > - Show quoted text -
> >
> > > > > Well excuse the holy hell out of me for not phrasing things the way
> > > > > you want it. *My references were based on the specifics of the two
> > > > > planes involved in the discussion and if you can't gleem that fact
> > > > > from it, too ****ing bad.
> >
> > > > Trying to retcon your comments and say that such and such wasn't what
> > > > you meant would work better if you...
> >
> > > I said what I ment but I can't help that you read into it something
> > > else.
> >
> > And you made the fact that the aircraft was a pusher an issue.
> >
> > You were wrong. Deal with it.
> >
>
> No, I never made the fact that the aircraft was a pusher into an
> issue...YOU DID. I simply pointed out different design elements of
> the two aircraft. You drew false conclusions from them and now try to
> make a issue from them.

Sigh....

"The Lancair is NOT a pusher..."

> >
> >
> > > > ...ACTUALLY SHOWED YOU UNDERSTOOD WHAT YOU'RE TALKING ABOUT...
> >
> > > I knew exactly what I was talking about but again, you read something
> > > into it beyond what I said. *That part is your problem not mine.
> >
> > Nope. Because the weight of an engine has precisely the same influence
> > on the aircraft at all times, operating or not.
> >
> >
>
> Gee do tell! Again you make false assumptions and then try and make
> some point from it.

Sigh...

"This is contrary to the standard configuration which requires a
downward force to counter the weight of the engine."

That's you attributing the engine's weight some special status when in
the nose, when if fact, it is the overall position of the centre of
gravity that matters.

>
> >
> > > > ...in your next post.
> >
> > > > You, OTOH, showed you still didn't get it and now you're getting ****y.
> >
> > > I am getting very tired of your arrogant attitude that ONLY YOU
> > > understand.
> >
> > Not "only me", just -- quite obviously -- not you.
> >
> >
> >
> > > > And the word your tiny little mind was scratching for was "glean".
> >
> > > Sorry but my typing isn't always the greatest and once again, your
> > > arrogance shows in thinking you are the only smart one in the group.
> >
> > Sorry, (and note the correct use of the comma, BTW) but the error wasn't
> > a typo, and you can't retcon it into one.
> >
>
> Yep, once again your arrogance rises to the occasion.

My ability to understand that typing "gleem" when the word you're
looking for is "glean" can't be a typo is "arrogance", now?

>
> >
> >
> > > > Always happy to help the ignorant.
> >
> > > Gee, so nice of you to come down from that tower you put yourself into
> > > and mingle with us common folk.
> >
> > Hey...
> >
> > You're more common than most.
> >
>
> And you are a lot more arrogant than most. Looking back through your
> posts it was clear that you felt the necessity to correct just about
> everyone. Guess that puts me in the good company of a lot of other
> common folk.

I correct things that are incorrect. Unlike you: who introduces
extraneous and erroneous points into a discussion, thus clouding the
issue.

The only thing that matter was thrust line. You kept introducing other
factors that were irrelevant.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[BobR]

On Nov 2, 8:22*pm, Alan Baker > wrote:
> In article
> >,
>
> *BobR > wrote:
> > On Nov 2, 5:56*pm, Alan Baker > wrote:
> > > In article
> > > >,
>
> > > *BobR > wrote:
>
> > > <snip>
>
> <snip>
>
>
>
>
>
> > > > > > > > > > > > Oh for gawd sake, you are talking about two totally
> > > > > > > > > > > > different
> > > > > > > > > > > > designs
> > > > > > > > > > > > and the aerodynamics of the two are totally different.

[Jim Logajan]

Alan Baker > wrote:
> The only thing that matter was thrust line.

You've managed to make the same incorrect claim at least twice (that I've
counted) in one thread. Are you sure you aren't overlooking something?

[Alan Baker]

In article
>,
BobR > wrote:

> On Nov 2, 8:22*pm, Alan Baker > wrote:
> > In article
> > >,
> >
> > *BobR > wrote:
> > > On Nov 2, 5:56*pm, Alan Baker > wrote:
> > > > In article
> > > > >,
> >
> > > > *BobR > wrote:
> >
> > > > <snip>
> >
> > <snip>
> >
> >
> >
> >
> >
> > > > > > > > > > > > > Oh for gawd sake, you are talking about two totally
> > > > > > > > > > > > > different
> > > > > > > > > > > > > designs
> > > > > > > > > > > > > and the aerodynamics of the two are totally
> > > > > > > > > > > > > different.
> > > > > > > > > > > > > *The
> > > > > > > > > > > > > Lancair
> > > > > > > > > > > > > is
> > > > > > > > > > > > > NOT a pusher and the engine is mounted forward of the
> > > > > > > > > > > > > CG
> > > > > > > > > > > > > instead
> > > > > > > > > > > > > of
> > > > > > > > > > > > > on
> > > > > > > > > > > > > top of it. *When the engine quits it will not pitch
> > > > > > > > > > > > > upward.
> > > > > > > > > > > > > *The
> > > > > > > > > > > > > plane
> > > > > > > > > > > > > you flew had the engine well above the center of
> > > > > > > > > > > > > gravity
> > > > > > > > > > > > > with
> > > > > > > > > > > > > a
> > > > > > > > > > > > > pusher
> > > > > > > > > > > > > prop and as a result produced a force that pushed the
> > > > > > > > > > > > > nose of
> > > > > > > > > > > > > the
> > > > > > > > > > > > > aircraft down. *The two planes would not act pretty
> > > > > > > > > > > > > much
> > > > > > > > > > > > > the
> > > > > > > > > > > > > same
> > > > > > > > > > > > > at
> > > > > > > > > > > > > all. *The weight of the engine on the Legacy is
> > > > > > > > > > > > > forward
> > > > > > > > > > > > > of
> > > > > > > > > > > > > the CG
> > > > > > > > > > > > > and
> > > > > > > > > > > > > as a result always pulling the nose of the plane
> > > > > > > > > > > > > down.
> > > > > > > > > > > > > *The
> > > > > > > > > > > > > counter
> > > > > > > > > > > > > to
> > > > > > > > > > > > > the nose down is the horizontal stabilizer and the
> > > > > > > > > > > > > elevator.
> > > > > > > > > > > > > *Look at
> > > > > > > > > > > > > the angle of incedence on the Horizontal Stabilizer
> > > > > > > > > > > > > and
> > > > > > > > > > > > > you
> > > > > > > > > > > > > will
> > > > > > > > > > > > > find
> > > > > > > > > > > > > a slight downward angle, not an upward angle as is
> > > > > > > > > > > > > common
> > > > > > > > > > > > > on
> > > > > > > > > > > > > the
> > > > > > > > > > > > > wing. *This counteracts the force from the weight of
> > > > > > > > > > > > > the
> > > > > > > > > > > > > engine.
> > > > > > > > > > > > > *An
> > > > > > > > > > > > > engine out condition will not have a significant
> > > > > > > > > > > > > effect
> > > > > > > > > > > > > on
> > > > > > > > > > > > > pitch
> > > > > > > > > > > > > until
> > > > > > > > > > > > > the airspeed changes and that will result in a nose
> > > > > > > > > > > > > down,
> > > > > > > > > > > > > not
> > > > > > > > > > > > > nose up
> > > > > > > > > > > > > pull.
> >
> > > > > > > > > > > > The one thing not quite right is that there is no
> > > > > > > > > > > > important
> > > > > > > > > > > > difference
> > > > > > > > > > > > between tractor vs. pusher configurations with respect
> > > > > > > > > > > > to
> > > > > > > > > > > > directional
> > > > > > > > > > > > stability.
> >
> > > > > > > > > > > Not sure what you are replying to but I never said
> > > > > > > > > > > anything
> > > > > > > > > > > about
> > > > > > > > > > > directional stability. *The discussion was regarding
> > > > > > > > > > > pitch
> > > > > > > > > > > forces.
> >
> > > > > > > > > > Which is essentially the same thing.
> >
> > > > > > > > > > Pusher or puller doesn't affect pitch forces. What affects
> > > > > > > > > > pitch
> > > > > > > > > > forces
> > > > > > > > > > is the length of the moment arm between the centre of mass
> > > > > > > > > > and
> > > > > > > > > > the
> > > > > > > > > > thrust line.
> >
> > > > > > > > > > > > Like some of the early rocket designers (e.g. Goddard),
> > > > > > > > > > > > you
> > > > > > > > > > > > are
> > > > > > > > > > > > falling
> > > > > > > > > > > > into the fallacy that somehow pulling is more stable
> > > > > > > > > > > > than
> > > > > > > > > > > > pushing.
> > > > > > > > > > > > This
> > > > > > > > > > > > is not so.
> >
> > > > > > > > > > - Show quoted text -
> >
> > > > > > > > > Again Alan, I never indicated any issue with pusher vs
> > > > > > > > > tractor.
> > > > > > > > > *The
> > > > > > > > > layout of the two planes being discussed is totally
> > > > > > > > > different.
> > > > > > > > > *One
> > > > > > > > > involved a tractor configuration with the thrust line being
> > > > > > > > > very
> > > > > > > > > near
> > > > > > > > > the vertical center of gravity. *The second involved an plane
> > > > > > > > > with
> > > > > > > > > the
> > > > > > > > > engine mounted on a pylon with a thrust line well above the
> > > > > > > > > vertical
> > > > > > > > > center of gravity. *This configuration, rather it be a
> > > > > > > > > tractor or
> > > > > > > > > pusher will induce nose down forces that must be countered by
> > > > > > > > > the
> > > > > > > > > horizontal stabilizer with an upward force. *This is contrary
> > > > > > > > > to
> > > > > > > > > the
> > > > > > > > > standard configuration which requires a downward force to
> > > > > > > > > counter
> > > > > > > > > the
> > > > > > > > > weight of the engine. *The post I was replying to was trying
> > > > > > > > > to
> > > > > > > > > link
> > > > > > > > > the characteristic of the pylon mounted configuration to the
> > > > > > > > > Legacy.
> >
> > > > > > > > Sorry, man, but you made specific reference to the plane being
> > > > > > > > a
> > > > > > > > pusher
> > > > > > > > as if it was a relevant factor:
> >
> > > > > > > > "The Lancair is NOT a pusher and the engine is mounted forward
> > > > > > > > of
> > > > > > > > the
> > > > > > > > CG
> > > > > > > > instead of on top of it. *When the engine quits it will not
> > > > > > > > pitch
> > > > > > > > upward. *The plane you flew had the engine well above the
> > > > > > > > center of
> > > > > > > > gravity with a pusher prop and as a result produced a force
> > > > > > > > that
> > > > > > > > pushed
> > > > > > > > the nose of the aircraft down."
> >
> > > > > > > > When you include extraneous details, you make the essence of
> > > > > > > > the
> > > > > > > > situation harder to glean.
> >
> > > > > > > > And you're doing it again. You're conflating thrust line
> > > > > > > > induced
> > > > > > > > pitch
> > > > > > > > changes with weight of engine. One is changing, one is
> > > > > > > > constant.
> >
> > > > > > > > The only part that you had to talk about was the fact that the
> > > > > > > > thrust
> > > > > > > > line was significantly above the centre of mass. The weight of
> > > > > > > > the
> > > > > > > > engine doesn't matter (in an aircraft that has it's centre of
> > > > > > > > gravity
> > > > > > > > appropriately located), nor does pusher vs. puller.
> >
> > > > > > > > - Show quoted text -
> >
> > > > > > > Well excuse the holy hell out of me for not phrasing things the
> > > > > > > way
> > > > > > > you want it. *My references were based on the specifics of the
> > > > > > > two
> > > > > > > planes involved in the discussion and if you can't gleem that
> > > > > > > fact
> > > > > > > from it, too ****ing bad.
> >
> > > > > > Trying to retcon your comments and say that such and such wasn't
> > > > > > what
> > > > > > you meant would work better if you...
> >
> > > > > I said what I ment but I can't help that you read into it something
> > > > > else.
> >
> > > > And you made the fact that the aircraft was a pusher an issue.
> >
> > > > You were wrong. Deal with it.
> >
> > > No, I never made the fact that the aircraft was a pusher into an
> > > issue...YOU DID. *I simply pointed out different design elements of
> > > the two aircraft. *You drew false conclusions from them and now try to
> > > make a issue from them.
> >
> > Sigh....
> >
> > "The Lancair is NOT a pusher..."
> >
>
> AND THAT IS WHERE YOU MIND WENT BLANK AND YOU STOPPED COMPREHENDING
> ANYTHING ELSE.

Nope.

I comprehended the rest fine.

You, OTOH, led of your reply with what you now claim was an
irrelevancy...


>
> >
> > > > > > ...ACTUALLY SHOWED YOU UNDERSTOOD WHAT YOU'RE TALKING ABOUT...
> >
> > > > > I knew exactly what I was talking about but again, you read something
> > > > > into it beyond what I said. *That part is your problem not mine.
> >
> > > > Nope. Because the weight of an engine has precisely the same influence
> > > > on the aircraft at all times, operating or not.
> >
> > > Gee do tell! *Again you make false assumptions and then try and make
> > > some point from it.
> >
> > Sigh...
> >
> > "This is contrary to the standard configuration which requires a
> > downward force to counter the weight of the engine."
> >
> > That's you attributing the engine's weight some special status when in
> > the nose, when if fact, it is the overall position of the centre of
> > gravity that matters.
> >
>
> Yep, the fact that it is FORWARD of the CG doesn't matter at all.
> Damn but you can't seem to understand anything that is not said
> exactly like you want it to be. Take one part out of context and try
> and make an entire argument from it.

Precisely correct. The fact that it is forward of the centre of *mass*
doesn't matter at all, because whatever the location of the engine, its
effect is the same whether its operating or not.

>
> >
> > > > > > ...in your next post.
> >
> > > > > > You, OTOH, showed you still didn't get it and now you're getting
> > > > > > ****y.
> >
> > > > > I am getting very tired of your arrogant attitude that ONLY YOU
> > > > > understand.
> >
> > > > Not "only me", just -- quite obviously -- not you.
> >
> > > > > > And the word your tiny little mind was scratching for was "glean".
> >
> > > > > Sorry but my typing isn't always the greatest and once again, your
> > > > > arrogance shows in thinking you are the only smart one in the group.
> >
> > > > Sorry, (and note the correct use of the comma, BTW) but the error
> > > > wasn't
> > > > a typo, and you can't retcon it into one.
> >
> > > Yep, once again your arrogance rises to the occasion.
> >
> > My ability to understand that typing "gleem" when the word you're
> > looking for is "glean" can't be a typo is "arrogance", now?
> >
>
> So I didn't spell the word correctly...big fking deal. You want to be
> my english teacher now too? The arrogance is that you couldn't help
> yourself and had to make an issue of that too.

But you didn't claim it was a spelling error. You claimed it was a
typo...

>
> >
> > > > > > Always happy to help the ignorant.
> >
> > > > > Gee, so nice of you to come down from that tower you put yourself
> > > > > into
> > > > > and mingle with us common folk.
> >
> > > > Hey...
> >
> > > > You're more common than most.
> >
> > > And you are a lot more arrogant than most. *Looking back through your
> > > posts it was clear that you felt the necessity to correct just about
> > > everyone. *Guess that puts me in the good company of a lot of other
> > > common folk.
> >
> > I correct things that are incorrect. Unlike you: who introduces
> > extraneous and erroneous points into a discussion, thus clouding the
> > issue.
> >
>
> No, you make issues where there were no issues and your arrogance
> doesn't allow any one else room to say anything. You had to pick
> apart my response without even trying to understand the point I was
> trying to get across. You still don't get it and never will. You did
> the same to everyone else who responded as well.

Sorry, but no. You make issues out of hwat (BTW, *that* is what a typo
looks like) are not issues.

>
> > The only thing that matter was thrust line. You kept introducing other
> > factors that were irrelevant.
> >
>
> That was clearly the only thing YOU BELIEVED mattered and clearly I
> didn't say it exactly the way you wanted. TOO BAD! Yes, in this
> particular case, the thrust line was important and I indicated such
> but not in those words. But what I was more interested in was
> pointing out that the two planes had totally different configurations
> and would react differently. You can't and will never accept that
> because you can't get beyond your own intrepretations an insist on
> talking down to everybody.

The thrust line was *all* that was important in this discussion. And
clearly, you still don't understand that.

The only difference in their configuration that matter in the case of
loss of engine power was where the thrust line was in relation to the
centre of mass. The whole pusher/puller and position of the engine's
weight were completely irrelevant.

Simple fact, and I'm sorry you can't get it.

>
> So at this point, I will simply yield to your superior knowledge of
> all things and say that you are always right. From this point on I
> will not try to make any posts unless you proof read them first. I
> will also encourage everyone else to do the same.

Great. The group will be better off for it.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Alan Baker]

In article >,
Jim Logajan > wrote:

> Alan Baker > wrote:
> > The only thing that matter was thrust line.
>
> You've managed to make the same incorrect claim at least twice (that I've
> counted) in one thread. Are you sure you aren't overlooking something?

I'm will to entertain that possibility.

What do you think I'm overlooking?

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Jim Logajan]

Alan Baker > wrote:
> In article >,
> Jim Logajan > wrote:
>
>> Alan Baker > wrote:
>> > The only thing that matter was thrust line.
>>
>> You've managed to make the same incorrect claim at least twice (that
>> I've counted) in one thread. Are you sure you aren't overlooking
>> something?
>
> I'm will to entertain that possibility.
>
> What do you think I'm overlooking?

That the aircraft are moving through a fluid, not a vacuum.

So things like propwash affect a tractor differently than a pusher. In my
own analysis of the two types and their engine on versus engine off
dynamics, the thrust line has not been "the only thing that matter[s]." It
is more complex, and the texts I have handy do not make the situation
appear as simple as you claim.

If thrust line moment arm (relative to the c.g.) were all that mattered,
then the following two bottle rocket firework designs would fly the same
paths, mass, impulse curve, c.g., and thrust moment arm being held the
same:

(A) ----------------+-----+
|=====]>

(B) +-----+----------------
|=====]>

The attachments to the sticks are made so that the moment arms relative to
the c.g. are otherwise identical, but in (B) the thrust is opposite its
usual direction. Now in a vacuum I would expect them to fly the same paths
and would be surprised if they didn't do that. But in a fluid like the
atmosphere? Would you expect them to fly the same or different paths?
Frankly, I would be surprised if they did fly the same - but as I don't
have any fireworks handy at the moment I haven't gone outside to have fun,
er, run experiments to observe their behavior.

[Alan Baker]

In article >,
Jim Logajan > wrote:

> Alan Baker > wrote:
> > In article >,
> > Jim Logajan > wrote:
> >
> >> Alan Baker > wrote:
> >> > The only thing that matter was thrust line.
> >>
> >> You've managed to make the same incorrect claim at least twice (that
> >> I've counted) in one thread. Are you sure you aren't overlooking
> >> something?
> >
> > I'm will to entertain that possibility.
> >
> > What do you think I'm overlooking?
>
> That the aircraft are moving through a fluid, not a vacuum.
>
> So things like propwash affect a tractor differently than a pusher. In my
> own analysis of the two types and their engine on versus engine off
> dynamics, the thrust line has not been "the only thing that matter[s]." It
> is more complex, and the texts I have handy do not make the situation
> appear as simple as you claim.
>
> If thrust line moment arm (relative to the c.g.) were all that mattered,
> then the following two bottle rocket firework designs would fly the same
> paths, mass, impulse curve, c.g., and thrust moment arm being held the
> same:
>
> (A) ----------------+-----+
> |=====]>
>
> (B) +-----+----------------
> |=====]>
>
> The attachments to the sticks are made so that the moment arms relative to
> the c.g. are otherwise identical, but in (B) the thrust is opposite its
> usual direction. Now in a vacuum I would expect them to fly the same paths
> and would be surprised if they didn't do that. But in a fluid like the
> atmosphere? Would you expect them to fly the same or different paths?
> Frankly, I would be surprised if they did fly the same - but as I don't
> have any fireworks handy at the moment I haven't gone outside to have fun,
> er, run experiments to observe their behavior.

Sorry, but you're proceeding from two wrong assumptions.

1. Your A and B examples would both behave the same in flight if their
centres of mass were both the same. It is the aerodynamic centre of
pressure moving ahead of the centre of mass that would cause B to be
unstable and A stable, if we operate from the assumption that the only
parts involved are the rocket and the stick.

2. In specific, both of the aircraft in this case are stable. They are
both stable because the aerodynamic centre of pressure is behind the
centre of mass and because the centre of lift of the main wing is behind
the centre of gravity. Thus, your assumption that a change in the
engines location matters is based on the erroneous assumption that such
a change is being made in isolation.

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

[Jim Logajan]

Alan Baker > wrote:
> Jim Logajan > wrote:
>> Alan Baker > wrote:
>> > Jim Logajan > wrote:
>> >> Alan Baker > wrote:
>> >> > The only thing that matter was thrust line.
>> >>
>> >> You've managed to make the same incorrect claim at least twice
>> >> (that I've counted) in one thread. Are you sure you aren't
>> >> overlooking something?
>> >
>> > I'm will to entertain that possibility.
>> >
>> > What do you think I'm overlooking?
>>
>> That the aircraft are moving through a fluid, not a vacuum.
>>
>> So things like propwash affect a tractor differently than a pusher.
>> In my own analysis of the two types and their engine on versus engine
>> off dynamics, the thrust line has not been "the only thing that
>> matter[s]." It is more complex, and the texts I have handy do not
>> make the situation appear as simple as you claim.
>>
>> If thrust line moment arm (relative to the c.g.) were all that
>> mattered, then the following two bottle rocket firework designs would
>> fly the same paths, mass, impulse curve, c.g., and thrust moment arm
>> being held the same:
>>
>> (A) ----------------+-----+
>> |=====]>
>>
>> (B) +-----+----------------
>> |=====]>
>>
>> The attachments to the sticks are made so that the moment arms
>> relative to the c.g. are otherwise identical, but in (B) the thrust
>> is opposite its usual direction. Now in a vacuum I would expect them
>> to fly the same paths and would be surprised if they didn't do that.
>> But in a fluid like the atmosphere? Would you expect them to fly the
>> same or different paths? Frankly, I would be surprised if they did
>> fly the same - but as I don't have any fireworks handy at the moment
>> I haven't gone outside to have fun, er, run experiments to observe
>> their behavior.
>
> Sorry, but you're proceeding from two wrong assumptions.

There is no dispute on your two points below. I'm glad to see you
understand about dynamic pressure - it was not evident (to me at least)
in your earlier posts. The problem still remains that your claim that the
"only thing that matter[s] was thrust line" is incompatible with the
aerodynamic differences between a tractor and pusher. You either read
past my second sentence "So things like propwash..." and it didn't
register or you did read it but still don't understand what you
"overlooked."

So here is again (in expanded form) what I think you overlooked:

Because tractor propwash generates forces on any aircraft surfaces in its
wake, so far as I know, no amount of thrust line adjustment can ever
eliminate the flight character differences between tractor and pusher
airplanes.

> 1. Your A and B examples would both behave the same in flight if their
> centres of mass were both the same. It is the aerodynamic centre of
> pressure moving ahead of the centre of mass that would cause B to be
> unstable and A stable, if we operate from the assumption that the only
> parts involved are the rocket and the stick.
>
> 2. In specific, both of the aircraft in this case are stable. They are
> both stable because the aerodynamic centre of pressure is behind the
> centre of mass and because the centre of lift of the main wing is
> behind the centre of gravity. Thus, your assumption that a change in
> the engines location matters is based on the erroneous assumption that
> such a change is being made in isolation.

[Highflyer]

"Gregory Hall" > wrote in message
...
>
>> I think it makes good sense. Look at the size of that engine up front.
>> Looks
> like a P-51 Mustang for pity sake. When you're being pulled along by that
> big prop and heavy, powerful engine it pulls the nose of the aircraft
> down. The horizontal stabilizers have to counteract this force by putting
> an upward force on the nose by pushing the tail down. If and when the
> engine suddenly dies the aircraft will pitch up suddenly and since the
> size of the stabilizers are so puny they might easily stall and be unable
> to counteract the upward pitch at the nose resulting in a tail down death
> spiral.
>
>> By the way, the Lancair Legacy is the most fun civilian airplane I've
>> flown and is the main reason I returned to general aviation after a
>> decades-long absence. I'm sure there is a Legacy near you and I'll bet
>> its pilot would be happy to take you for a ride. You can see for
>> yourself what a great airplane it is.
>
> It looks too much like an irresponsible, hot rod, stunt plane to me. Is it
> any wonder so many companies offering homebuilt aircraft have gone out of
> business?
>
> http://www.homebuilt.org/aircraft/nolonger.html
>
> This is the safest homebuilt IMO.(VariEze ). The canard makes it
> foolproof.
>
> http://video.google.com.au/videoplay?docid=-7074107135477166441&hl=en
>
> --
> Gregory Hall
>

Gregory,

You have managed to prove quite indisputably to the entire group that you
really do not know the first thing about
aerodynamics or aircraft design.

You are totally and incontrovertibly wrong.

By the way, the canard does NOT make it foolproof. As a matter of fact I
recall Burt running up and down the runway
in an old beater car with his windtunnel models mounted on it, getting the
data he needed to make the canard arrangement
he used on several designs safe. It is much easier to design a safe
airplane with a conventional tail.

The Lancair Legacy has very light and quick response to the controls. That
makes an airplane FUN to fly. Especially
if you are a good pilot, and BWB was a good pilot. I flew with him in his
RV-6 at Pinckneyville the year he brought it
to the Pinckneyville Flyin.

The problem with an airplane like the Lancair occurs when the **** hits the
fan at low altitude. The airplane responds
quickly and it is fast. A momentary distraction can allow a considerable
unplanned excursion. If something relatively
immoveable intrudes itself into your flight path during that unplanned
excursion bad **** can happen. I believe bad ****
did in this case. Obviously unusual things were going on. Stuff was
drooling out of the airplane.

I am not going to guess what happened. There was an accident. I lost
another friend. I have lost too many friends that
way over the years. Janice is recovering. Slowly. Painfully. Bill did
not. We disagreed about many things over the
years. Some of them were, I am sure, due to failures in communication or
misunderstandings. That happens. I will
miss his sorry ass.

Highflyer
Highflight Aviation Services
Pinckneyville Airport ( PJY )

[Highflyer]

"Steve Hix" > wrote in message
...
> In article
> >,
> Alan Baker > wrote:
>
>> You have to take moments about something that isn't going to shift,
>> Steve. Centre of mass.
>

Steve replied ...

> I know that that doesn't change (ignoring fuel burn), but things like
> flaps' contribution to drag moments changes with changes in
> configuration.
>
> Else we'd never see pitch changes as we raise or lower the flaps, or
> changes in speed as landing gear are retracted or extended.

Semantics can really make things confused. In aerodynamics and aircraft
design we simplify things to make the
math a bit easier. Instead of dealing with forces that move all over the
place and make it difficult to superimpose
mathematically to calculate their resolution and the resultant vectors which
would get relatively intractable, we
pick a point more or less at random and say "The force acts HERE!" Then we
figure out the moments about that
point contributed by our other factors. Then we merely sum up the moments,
using the appropriate arithmetic for
summing up vectors of course, and determine the resultant forces relatively
easily. To make this simplification
work we need to pick arbitrary points that don't move around. Things like
the "center of mass", or the "center of
lateral area", or the "center of gravity", or the "quarter chord line of the
lifting surface" and then we find how the
moments change about that point. We can even play additional simplification
games and normalize the actual moments
into a dimensionless coeficcient. If you look at a plot of the forces on a
wing you will see alongside the lift/drag
polar, another line labeled "moment coefficient." This moment coefficient
tells you how the center of lift moves about
relative to the quarter chord line of the wing. The neat thing about the
NACA 23012 airfoil section is the moment
coefficient is approximately zero throughout the normal angle of attack
range. This means the center of lift doesn't move
around very much on the wing. This is what made possible the monospar wing
on the DC-3! :-)

Highflyer
Highflight Aviation Services
Pinckneyville Airport ( PJY )

[[email protected]]

On Sat, 8 Nov 2008 01:11:51 -0600, "Highflyer" > wrote:

>
>"Gregory Hall" > wrote in message
...
>>
>>> I think it makes good sense. Look at the size of that engine up front.
>>> Looks
>> like a P-51 Mustang for pity sake. When you're being pulled along by that
>> big prop and heavy, powerful engine it pulls the nose of the aircraft
>> down. The horizontal stabilizers have to counteract this force by putting
>> an upward force on the nose by pushing the tail down. If and when the
>> engine suddenly dies the aircraft will pitch up suddenly and since the
>> size of the stabilizers are so puny they might easily stall and be unable
>> to counteract the upward pitch at the nose resulting in a tail down death
>> spiral.
>>
>>> By the way, the Lancair Legacy is the most fun civilian airplane I've
>>> flown and is the main reason I returned to general aviation after a
>>> decades-long absence. I'm sure there is a Legacy near you and I'll bet
>>> its pilot would be happy to take you for a ride. You can see for
>>> yourself what a great airplane it is.
>>
>> It looks too much like an irresponsible, hot rod, stunt plane to me. Is it
>> any wonder so many companies offering homebuilt aircraft have gone out of
>> business?
>>
>> http://www.homebuilt.org/aircraft/nolonger.html
>>
>> This is the safest homebuilt IMO.(VariEze ). The canard makes it
>> foolproof.

Actually it doesn't. Take an old time pilot coming in at 1.3 Vso, go
into the flare holding the nose up. Bad place to do that in the
canard. And if you don't load them right even they can be put into a
deep stall as opposed to the common kind.



Maybe I'm just used to planes with an attitude, but the Deb has a very
abrupt stall with a very strong tendency to roll left at the break.
Get used to it and it's like flying most anything else. Even if it
does take a bit more to stay proficient.
>>
I would choose the Legacy in a minute. Does it need a bigger stab?
I'd have to play with one for a while, but they are all compromise.
Most of the fast, hot planes are not for the low timer or pilot who
only flies once a month.

Me? I love big engines in small planes, but I do like enough vertical
and horizontal stab with rudder and elevator authority to do
spins.<:-))

I don't see the Legacy as any more dangerous or radical than any of
the other high performance planes out there.





>> http://video.google.com.au/videoplay?docid=-7074107135477166441&hl=en
>>
>> --
>> Gregory Hall
>>
>
>Gregory,
>
>You have managed to prove quite indisputably to the entire group that you
>really do not know the first thing about
>aerodynamics or aircraft design.
>
>You are totally and incontrovertibly wrong.
>
>By the way, the canard does NOT make it foolproof. As a matter of fact I
>recall Burt running up and down the runway
>in an old beater car with his windtunnel models mounted on it, getting the
>data he needed to make the canard arrangement
>he used on several designs safe. It is much easier to design a safe
>airplane with a conventional tail.
>
>The Lancair Legacy has very light and quick response to the controls. That
>makes an airplane FUN to fly. Especially
>if you are a good pilot, and BWB was a good pilot. I flew with him in his
>RV-6 at Pinckneyville the year he brought it
>to the Pinckneyville Flyin.
>
>The problem with an airplane like the Lancair occurs when the **** hits the
>fan at low altitude. The airplane responds
>quickly and it is fast. A momentary distraction can allow a considerable
>unplanned excursion. If something relatively
>immoveable intrudes itself into your flight path during that unplanned
>excursion bad **** can happen. I believe bad ****
>did in this case. Obviously unusual things were going on. Stuff was
>drooling out of the airplane.
>
>I am not going to guess what happened. There was an accident. I lost
>another friend. I have lost too many friends that
>way over the years. Janice is recovering. Slowly. Painfully. Bill did
>not. We disagreed about many things over the
>years. Some of them were, I am sure, due to failures in communication or
>misunderstandings. That happens. I will
>miss his sorry ass.
>
>Highflyer
>Highflight Aviation Services
>Pinckneyville Airport ( PJY )
>
Roger (K8RI) ARRL Life Member
N833R (World's oldest Debonair)
www.rogerhalstead.com