Lancair Legacy Design Flaw?

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!

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

"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

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.

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

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 -

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

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

If I may save Jim the trouble....


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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.