Prop angle of attack vs age

[sid]

On older planes, does the angle of attack change ? Does the prop angle
relax like a motorboat prop does after 1 or 2 decades of constant
use ? (fixed pitch of course)

There are some older warriors on the field (20 - 25) years, and it
seems that there props don't have the bite that the new warrior (10
years old) does.

Thanks

[Bertie the Bunyip[_24_]]

sid > wrote in news:702f8b8d-b77e-452c-904c-
:

> On older planes, does the angle of attack change ? Does the prop angle
> relax like a motorboat prop does after 1 or 2 decades of constant
> use ? (fixed pitch of course)
>
> There are some older warriors on the field (20 - 25) years, and it
> seems that there props don't have the bite that the new warrior (10
> years old) does.
>

No, but years of wear and dressing the prop because of nicks and what not
doesn't do them any good at all.


Bertie
>

[Stealth Pilot[_2_]]

On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip >
wrote:

>sid > wrote in news:702f8b8d-b77e-452c-904c-
:
>
>> On older planes, does the angle of attack change ? Does the prop angle
>> relax like a motorboat prop does after 1 or 2 decades of constant
>> use ? (fixed pitch of course)
>>
>> There are some older warriors on the field (20 - 25) years, and it
>> seems that there props don't have the bite that the new warrior (10
>> years old) does.
>>
>
>No, but years of wear and dressing the prop because of nicks and what not
>doesn't do them any good at all.
>
>
>Bertie
>>

I have a fibreglass covered wooden prop which makes it reasonably
resilient in light rain. I paint it.
when the aforesaid light rain has eroded the paint near the leading
edge I lose 5 knots in cruise speed.

also If I alter the shape with a poor paint coat I lose cruise speed.

the other factor with some commercial aircraft is that there are often
3 props approved for them. a climb, a utility and a cruise prop.
on little cessnas they are each 2 inches of pitch apart.
memories of cruise with a cruise prop would make cruise on a climb
prop seem quite anaemic.

.....and what bertie wrote.

Stealth Pilot

[[email protected]]

On Jul 11, 7:09*am, Stealth Pilot >
wrote:
> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip >
> wrote:
>
>
>
> >sid > wrote in news:702f8b8d-b77e-452c-904c-
> :
>
> >> On older planes, does the angle of attack change ? Does the prop angle
> >> relax like a motorboat prop does after 1 or 2 decades of constant
> >> use ? (fixed pitch of course)
>
> >> There are some older warriors on the field (20 - 25) years, and it
> >> seems that there props don't have the bite that the new warrior (10
> >> years old) does.
>
> >No, but years of wear and dressing the prop because of nicks and what not
> >doesn't do them any good at all.
>
> >Bertie
>
> I have a fibreglass covered wooden prop which makes it reasonably
> resilient in light rain. I paint it.
> when the aforesaid light rain has eroded the paint *near the leading
> edge I lose 5 knots in cruise speed.
>
> also If I alter the shape with a poor paint coat I lose cruise speed.
>
> the other factor with some commercial aircraft is that there are often
> 3 props approved for them. a climb, a utility and a cruise prop.
> on little cessnas they are each 2 inches of pitch apart.
> memories of cruise with a cruise prop would make cruise on a climb
> prop seem quite anaemic.
>
> ....and what bertie wrote.
>
> Stealth Pilot

I can understand why a poor -- as in not smooth -- paint job would
alter the prop's efficiency, but never would have guessed having a
fractional mm of paint ablated from the leading edge of the prop would
affect it that much. Tongue in cheek question -- did the natural color
of the prop clash with that color and scare the air, or something?

On a serious note, have you any thoughts as to why such a minor change
in shape would have such a remarkable change in efficiency? A 5 knot
change in airspeed is like reducing the manifold an inch or so, isn't
it? That's huge! It also suggests there may be very minor changes in
prop that could improve performance too.

l

[Maxwell[_2_]]

> wrote in message
...

I can understand why a poor -- as in not smooth -- paint job would
alter the prop's efficiency, but never would have guessed having a
fractional mm of paint ablated from the leading edge of the prop would
affect it that much. Tongue in cheek question -- did the natural color
of the prop clash with that color and scare the air, or something?

On a serious note, have you any thoughts as to why such a minor change
in shape would have such a remarkable change in efficiency? A 5 knot
change in airspeed is like reducing the manifold an inch or so, isn't
it? That's huge! It also suggests there may be very minor changes in
prop that could improve performance too.

---------------------------------------------------

You are absolutely right, and his is just exaggerating again as usual.

Just keep an eye on his posts, you will come to expect it in time.

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in news:ZhKdk.20173$%q.11589
@newsfe24.lga:

>
> > wrote in message
> ...
>
> I can understand why a poor -- as in not smooth -- paint job would
> alter the prop's efficiency, but never would have guessed having a
> fractional mm of paint ablated from the leading edge of the prop would
> affect it that much. Tongue in cheek question -- did the natural color
> of the prop clash with that color and scare the air, or something?
>
> On a serious note, have you any thoughts as to why such a minor change
> in shape would have such a remarkable change in efficiency? A 5 knot
> change in airspeed is like reducing the manifold an inch or so, isn't
> it? That's huge! It also suggests there may be very minor changes in
> prop that could improve performance too.
>
> ---------------------------------------------------
>
> You are absolutely right, and his is just exaggerating again as usual.

Like you'd know, fjukktard.
>
> Just keep an eye on his posts, you will come to expect it in time.



Snort!


Bertie

[sid]

On Jul 11, 12:14*pm, Bertie the Bunyip > wrote:
> "Maxwell" <luv2^fly99@cox.^net> wrote in news:ZhKdk.20173$%q.11589
> @newsfe24.lga:
>
>
>
>
>
>
>
> > > wrote in message
> ....
>
> > I can understand why a poor -- as in not smooth -- paint job would
> > alter the prop's efficiency, but never would have guessed having a
> > fractional mm of paint ablated from the leading edge of the prop would
> > affect it that much. Tongue in cheek question -- did the natural color
> > of the prop clash with that color and scare the air, or something?
>
> > On a serious note, have you any thoughts as to why such a minor change
> > in shape would have such a remarkable change in efficiency? A 5 knot
> > change in airspeed is like reducing the manifold an inch or so, isn't
> > it? That's huge! It also suggests there may be very minor changes in
> > prop that could improve performance too.
>
> > ---------------------------------------------------
>
> > You are absolutely right, and his is just exaggerating again as usual.
>
> Like you'd know, fjukktard.
>
>
>
> > Just keep an eye on his posts, you will come to expect it in time.
>
> Snort!
>
> Bertie- Hide quoted text -
>
> - Show quoted text -

Not knowing much about props, what do you mean by "... they are each
2 inches of pitch apart." ?
I thought props were measured in dia. and angle ?

Thanks

[Maxwell[_2_]]

"sid" > wrote in message
...

Not knowing much about props, what do you mean by "... they are each
2 inches of pitch apart." ?
I thought props were measured in dia. and angle ?

Thanks

--------------------------------------------------------------------

A propellers angle or pitch is expressed in inches. Theoretically, a 24"
pitch prop has an angle that would travel 24" forward with each revolution,
at zero angle of attack. The smaller the number, the flatter the prop.

If that seems confusing, consider a right trangle. If the circumference of
the propeller arc at any given station is the base, the pitch is the height,
and the resulting angle is the pitch angle for that station. That's why
props have less angle at the tip, than at the root. Theoretically, it keeps
the entire lenght of the blade working at the same angle of attack.

Thus climb props are flatter or less pitch, and cruise props have more.

[sid]

On Jul 11, 3:13*pm, "Maxwell" <luv2^fly99@cox.^net> wrote:
> "sid" > wrote in message
>
> ...
>
> Not knowing much about props, what do you mean by *"... they are each
> 2 inches of pitch apart." ?
> I thought props were measured in dia. and angle ?
>
> Thanks
>
> --------------------------------------------------------------------
>
> A propellers angle or pitch is expressed in inches. Theoretically, a 24"
> pitch prop has an angle that would travel 24" forward with each revolution,
> at zero angle of attack. The smaller the number, the flatter the prop.
>
> If that seems confusing, consider a right trangle. If the circumference of
> the propeller arc at any given station is the base, the pitch is the height,
> and the resulting angle is the pitch angle for that station. That's why
> props have less angle at the tip, than at the root. Theoretically, it keeps
> the entire lenght of the blade working at the same angle of attack.
>
> Thus climb props are flatter or less pitch, and cruise props have more.

That’s a good explanation.

Looking in my Warrior II Information manual, the prop is listed as a:
Sensenich 74DM6-0-60 or 74DM6-0-58.
Is the "inches of pitch" encoded in that number ?

[Bob Noel]

In article >,
sid > wrote:

> Looking in my Warrior II Information manual, the prop is listed as a:
> Sensenich 74DM6-0-60 or 74DM6-0-58.
> Is the "inches of pitch" encoded in that number ?

Yes. 60 and 58

--
Bob Noel
(goodness, please trim replies!!!)

[Jay Maynard]

On 2008-07-12, sid > wrote:
> Looking in my Warrior II Information manual, the prop is listed as a:
> Sensenich 74DM6-0-60 or 74DM6-0-58.
> Is the "inches of pitch" encoded in that number ?

Yup...the -60 or -58 is the pitch at 3/4 of the blade length. (The 74 is the
diameter in inches.)
--
Jay Maynard, K5ZC http://www.conmicro.com
http://jmaynard.livejournal.com http://www.tronguy.net
Fairmont, MN (FRM) (Yes, that's me!)
AMD Zodiac CH601XLi N55ZC (got it!)

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in
:

>
> "sid" > wrote in message
> news:799b2347-57da-401d-b49a-d012f9053f35
@l42g2000hsc.googlegroups.com.
> ..
>
> Not knowing much about props, what do you mean by "... they are each
> 2 inches of pitch apart." ?
> I thought props were measured in dia. and angle ?
>
> Thanks
>
> --------------------------------------------------------------------
>
> A propellers angle or pitch is expressed in inches. Theoretically, a
> 24" pitch prop has an angle that would travel 24" forward with each
> revolution, at zero angle of attack. The smaller the number, the
> flatter the prop.
>
> If that seems confusing, consider a right trangle. If the
> circumference of the propeller arc at any given station is the base,
> the pitch is the height, and the resulting angle is the pitch angle
> for that station. That's why props have less angle at the tip, than at
> the root. Theoretically, it keeps the entire lenght of the blade
> working at the same angle of attack.
>
> Thus climb props are flatter or less pitch, and cruise props have
> more.
>


nice cuat and paste luser boi.


Bertie
>

[Stealth Pilot[_2_]]

On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote:

>On Jul 11, 7:09*am, Stealth Pilot >
>wrote:
>> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip >
>> wrote:
>>
>>
>>
>> >sid > wrote in news:702f8b8d-b77e-452c-904c-
>> :
>>
>> >> On older planes, does the angle of attack change ? Does the prop angle
>> >> relax like a motorboat prop does after 1 or 2 decades of constant
>> >> use ? (fixed pitch of course)
>>
>> >> There are some older warriors on the field (20 - 25) years, and it
>> >> seems that there props don't have the bite that the new warrior (10
>> >> years old) does.
>>
>> >No, but years of wear and dressing the prop because of nicks and what not
>> >doesn't do them any good at all.
>>
>> >Bertie
>>
>> I have a fibreglass covered wooden prop which makes it reasonably
>> resilient in light rain. I paint it.
>> when the aforesaid light rain has eroded the paint *near the leading
>> edge I lose 5 knots in cruise speed.
>>
>> also If I alter the shape with a poor paint coat I lose cruise speed.
>>
>> the other factor with some commercial aircraft is that there are often
>> 3 props approved for them. a climb, a utility and a cruise prop.
>> on little cessnas they are each 2 inches of pitch apart.
>> memories of cruise with a cruise prop would make cruise on a climb
>> prop seem quite anaemic.
>>
>> ....and what bertie wrote.
>>
>> Stealth Pilot
>
>I can understand why a poor -- as in not smooth -- paint job would
>alter the prop's efficiency, but never would have guessed having a
>fractional mm of paint ablated from the leading edge of the prop would
>affect it that much. Tongue in cheek question -- did the natural color
>of the prop clash with that color and scare the air, or something?
>
>On a serious note, have you any thoughts as to why such a minor change
>in shape would have such a remarkable change in efficiency? A 5 knot
>change in airspeed is like reducing the manifold an inch or so, isn't
>it? That's huge! It also suggests there may be very minor changes in
>prop that could improve performance too.
>
>l

the prop had a fairly average sheath put on it. average workmanship.
I use the paint layers to fair the surface to a smoother shape.
the face I see is painted matte black to make it invisible.
the leading edge is blue, the rest varnish.
chipped paint just creates a turbulator which seems to affect this
blade section. (clark Y, aka naca 44xx series)

I got 5 extra knots in cruise for nothing when I cleaned up the prop
and got the shape right the first time. the damaged leading edge paint
just drops me back to the original slower cruise.

Stealth Pilot

[Stealth Pilot[_2_]]

On Fri, 11 Jul 2008 09:40:54 -0500, "Maxwell" <luv2^fly99@cox.^net>
wrote:

>
> wrote in message
...
>
>I can understand why a poor -- as in not smooth -- paint job would
>alter the prop's efficiency, but never would have guessed having a
>fractional mm of paint ablated from the leading edge of the prop would
>affect it that much. Tongue in cheek question -- did the natural color
>of the prop clash with that color and scare the air, or something?
>
>On a serious note, have you any thoughts as to why such a minor change
>in shape would have such a remarkable change in efficiency? A 5 knot
>change in airspeed is like reducing the manifold an inch or so, isn't
>it? That's huge! It also suggests there may be very minor changes in
>prop that could improve performance too.
>
>---------------------------------------------------
>
>You are absolutely right, and his is just exaggerating again as usual.
>
>Just keep an eye on his posts, you will come to expect it in time.
>
>

unlike retards like you maxie I actually regularly fly and have a real
life. I have no need to exaggerate. life is sweet enough for me using
the real numbers.

Stealth Pilot

[sid]

On Jul 12, 7:39*am, Stealth Pilot >
wrote:
> On Fri, 11 Jul 2008 09:40:54 -0500, "Maxwell" <luv2^fly99@cox.^net>
> wrote:
>
>
>
>
>
>
>
> > wrote in message
> ....
>
> >I can understand why a poor -- as in not smooth -- paint job would
> >alter the prop's efficiency, but never would have guessed having a
> >fractional mm of paint ablated from the leading edge of the prop would
> >affect it that much. Tongue in cheek question -- did the natural color
> >of the prop clash with that color and scare the air, or something?
>
> >On a serious note, have you any thoughts as to why such a minor change
> >in shape would have such a remarkable change in efficiency? A 5 knot
> >change in airspeed is like reducing the manifold an inch or so, isn't
> >it? That's huge! It also suggests there may be very minor changes in
> >prop that could improve performance too.
>
> >---------------------------------------------------
>
> >You are absolutely right, and his is just exaggerating again as usual.
>
> >Just keep an eye on his posts, you will come to expect it in time.
>
> unlike retards like you maxie I actually regularly fly and have a real
> life. I have no need to exaggerate. life is sweet enough for me using
> the real numbers.
>
> Stealth Pilot- Hide quoted text -
>
> - Show quoted text -

So of the 2 props, 58" and 60" Which would be considered the cruise
and which is the performance ?
Or are they not far enough apart to tell the difference ?

[[email protected]]

On Jul 12, 8:37*am, Stealth Pilot >
wrote:
> On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote:
> >On Jul 11, 7:09*am, Stealth Pilot >
> >wrote:
> >> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip >
> >> wrote:
>
> >> >sid > wrote in news:702f8b8d-b77e-452c-904c-
> >> :
>
> >> >> On older planes, does the angle of attack change ? Does the prop angle
> >> >> relax like a motorboat prop does after 1 or 2 decades of constant
> >> >> use ? (fixed pitch of course)
>
> >> >> There are some older warriors on the field (20 - 25) years, and it
> >> >> seems that there props don't have the bite that the new warrior (10
> >> >> years old) does.
>
> >> >No, but years of wear and dressing the prop because of nicks and what not
> >> >doesn't do them any good at all.
>
> >> >Bertie
>
> >> I have a fibreglass covered wooden prop which makes it reasonably
> >> resilient in light rain. I paint it.
> >> when the aforesaid light rain has eroded the paint *near the leading
> >> edge I lose 5 knots in cruise speed.
>
> >> also If I alter the shape with a poor paint coat I lose cruise speed.
>
> >> the other factor with some commercial aircraft is that there are often
> >> 3 props approved for them. a climb, a utility and a cruise prop.
> >> on little cessnas they are each 2 inches of pitch apart.
> >> memories of cruise with a cruise prop would make cruise on a climb
> >> prop seem quite anaemic.
>
> >> ....and what bertie wrote.
>
> >> Stealth Pilot
>
> >I can understand why a poor -- as in not smooth -- paint job would
> >alter the prop's efficiency, but never would have guessed having a
> >fractional mm of paint ablated from the leading edge of the prop would
> >affect it that much. Tongue in cheek question -- did the natural color
> >of the prop clash with that color and scare the air, or something?
>
> >On a serious note, have you any thoughts as to why such a minor change
> >in shape would have such a remarkable change in efficiency? A 5 knot
> >change in airspeed is like reducing the manifold an inch or so, isn't
> >it? That's huge! It also suggests there may be very minor changes in
> >prop that could improve performance too.
>
> >l
>
> the prop had a fairly average sheath put on it. average workmanship.
> I use the paint layers to fair the surface to a smoother shape.
> the face I see is painted matte black to make it invisible.
> the leading edge is blue, the rest varnish.
> chipped paint just creates a turbulator which seems to affect this
> blade section. (clark Y, aka naca 44xx series)
>
> I got 5 extra knots in cruise for nothing when I cleaned up the prop
> and got the shape right the first time. the damaged leading edge paint
> just drops me back to the original slower cruise.
>
> Stealth Pilot

Five knots is a huge gain. I remember reading some years ago of a
homebuilt getting a new paint job, and the color change on the wings
led to a paint 'bump' or seam near the leading edge which so altered
the airflow the airplane could not fly (probably changed the
stagnation line). Still, that big a change in cruise speed seems
remarkable.

In that I fly behind controllable pitch props it's nothing I'd have
noticed, but still, if TLC gains that kind of speed advantage it
should be standard of care for propellers.

[Stealth Pilot[_2_]]

On Sat, 12 Jul 2008 05:49:29 -0700 (PDT), sid >
wrote:

>On Jul 12, 7:39*am, Stealth Pilot >
>wrote:
>> On Fri, 11 Jul 2008 09:40:54 -0500, "Maxwell" <luv2^fly99@cox.^net>
>> wrote:
>>
>>
>>
>>
>>
>>
>>
>> > wrote in message
>> ...
>>
>> >I can understand why a poor -- as in not smooth -- paint job would
>> >alter the prop's efficiency, but never would have guessed having a
>> >fractional mm of paint ablated from the leading edge of the prop would
>> >affect it that much. Tongue in cheek question -- did the natural color
>> >of the prop clash with that color and scare the air, or something?
>>
>> >On a serious note, have you any thoughts as to why such a minor change
>> >in shape would have such a remarkable change in efficiency? A 5 knot
>> >change in airspeed is like reducing the manifold an inch or so, isn't
>> >it? That's huge! It also suggests there may be very minor changes in
>> >prop that could improve performance too.
>>
>> >---------------------------------------------------
>>
>> >You are absolutely right, and his is just exaggerating again as usual.
>>
>> >Just keep an eye on his posts, you will come to expect it in time.
>>
>> unlike retards like you maxie I actually regularly fly and have a real
>> life. I have no need to exaggerate. life is sweet enough for me using
>> the real numbers.
>>
>> Stealth Pilot- Hide quoted text -
>>
>> - Show quoted text -
>
>So of the 2 props, 58" and 60" Which would be considered the cruise
>and which is the performance ?
>Or are they not far enough apart to tell the difference ?
>
the lower the number the finer the pitch.
the cruise prop, ie the one more optimised for higher speed cruise, is
the 60" prop.
the vanilla prop for better climb performance and slower cruise would
be the 58" prop.
you will notice the difference immediately.

if you are thinking of playing with props be careful.

the coarser pitch cruise prop will need more runway for the takeoff
and the climb out will be worse, but once up at altitude and trimmed
for cruise you will see a higher speed.

the lower pitch prop will give better takeoff performance and will
climb you out a little better but will cruise slower.

if you think about it you've just seen the reason variable pitch props
were developed. fine pitch for takeoff and coarse pitch for cruise.

the pitch figure is for the most effective point on the prop which is
the 70% radius position.
here are losses toward the hub and tip losses outboard of that
position so the rule of thumb is to use the 70% position for pitch
calculations.

it isnt hard to work out what your prop is doing. the secret is to get
everything into common units, typically feet per minute.
60" is 5ft. 5ft x 2500rpm = theoretical speed in ft/minute.

cruise speed in knots x 6080 = speed in feet per hour.
divide that by 60 and you have speed in feet per minute.

compare the two and you'll see what the prop's slip is.

if you work out the circumfrence of the circle at the 70% point
and do some arc tan on the pitch vs circumference you can work out the
flying angle of your prop (at the 70% point).

mine flies at close to 4 degrees in cruise.


Stealth Pilot

[Stealth Pilot[_2_]]

On Sat, 12 Jul 2008 05:53:59 -0700 (PDT), wrote:

>On Jul 12, 8:37*am, Stealth Pilot >
>wrote:
>> On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote:
>> >On Jul 11, 7:09*am, Stealth Pilot >
>> >wrote:
>> >> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip >
>> >> wrote:
>>
>> >> >sid > wrote in news:702f8b8d-b77e-452c-904c-
>> >> :
>>
>> >> >> On older planes, does the angle of attack change ? Does the prop angle
>> >> >> relax like a motorboat prop does after 1 or 2 decades of constant
>> >> >> use ? (fixed pitch of course)
>>
>> >> >> There are some older warriors on the field (20 - 25) years, and it
>> >> >> seems that there props don't have the bite that the new warrior (10
>> >> >> years old) does.
>>
>> >> >No, but years of wear and dressing the prop because of nicks and what not
>> >> >doesn't do them any good at all.
>>
>> >> >Bertie
>>
>> >> I have a fibreglass covered wooden prop which makes it reasonably
>> >> resilient in light rain. I paint it.
>> >> when the aforesaid light rain has eroded the paint *near the leading
>> >> edge I lose 5 knots in cruise speed.
>>
>> >> also If I alter the shape with a poor paint coat I lose cruise speed.
>>
>> >> the other factor with some commercial aircraft is that there are often
>> >> 3 props approved for them. a climb, a utility and a cruise prop.
>> >> on little cessnas they are each 2 inches of pitch apart.
>> >> memories of cruise with a cruise prop would make cruise on a climb
>> >> prop seem quite anaemic.
>>
>> >> ....and what bertie wrote.
>>
>> >> Stealth Pilot
>>
>> >I can understand why a poor -- as in not smooth -- paint job would
>> >alter the prop's efficiency, but never would have guessed having a
>> >fractional mm of paint ablated from the leading edge of the prop would
>> >affect it that much. Tongue in cheek question -- did the natural color
>> >of the prop clash with that color and scare the air, or something?
>>
>> >On a serious note, have you any thoughts as to why such a minor change
>> >in shape would have such a remarkable change in efficiency? A 5 knot
>> >change in airspeed is like reducing the manifold an inch or so, isn't
>> >it? That's huge! It also suggests there may be very minor changes in
>> >prop that could improve performance too.
>>
>> >l
>>
>> the prop had a fairly average sheath put on it. average workmanship.
>> I use the paint layers to fair the surface to a smoother shape.
>> the face I see is painted matte black to make it invisible.
>> the leading edge is blue, the rest varnish.
>> chipped paint just creates a turbulator which seems to affect this
>> blade section. (clark Y, aka naca 44xx series)
>>
>> I got 5 extra knots in cruise for nothing when I cleaned up the prop
>> and got the shape right the first time. the damaged leading edge paint
>> just drops me back to the original slower cruise.
>>
>> Stealth Pilot
>
>Five knots is a huge gain. I remember reading some years ago of a
>homebuilt getting a new paint job, and the color change on the wings
>led to a paint 'bump' or seam near the leading edge which so altered
>the airflow the airplane could not fly (probably changed the
>stagnation line). Still, that big a change in cruise speed seems
>remarkable.
>
>In that I fly behind controllable pitch props it's nothing I'd have
>noticed, but still, if TLC gains that kind of speed advantage it
>should be standard of care for propellers.

I repainted the prop (and rebalanced it) and replaced the windscreen
plastic and saw an 11knot increase in cruise speed.
this is after an extensive period of taping up seams and other toying
that saw absolutely no improvement at all.

it took my aero engineer friend about a month to work out what I'd
accidently done.

it was ...put back all the windscreen bolts.

this removed some blasts of air into the low pressure zone over the
windscreen.
the blasts of air were doing two things my aero engineer friend
deduced.
reducing the depression in pressure over the wing which reduced the
lift and required a slight increase in angle of attack which increased
induced drag.
increased the thickness of the boundary layer which increased drag.

the jump in performance on the first flight was just stunning to
behold. where before I could just make 120 knots balls to the wall in
a flypast I can now easily achieve 145 knots at max rpm after a dive.

your controllable prop gives you so much of an advantage.

Stealth Pilot

[More_Flaps]

On Jul 13, 12:53*am, wrote:
> On Jul 12, 8:37*am, Stealth Pilot >
> wrote:
>
>
>
> > On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote:
> > >On Jul 11, 7:09*am, Stealth Pilot >
> > >wrote:
> > >> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip >
> > >> wrote:
>
> > >> >sid > wrote in news:702f8b8d-b77e-452c-904c-
> > >> :
>
> > >> >> On older planes, does the angle of attack change ? Does the prop angle
> > >> >> relax like a motorboat prop does after 1 or 2 decades of constant
> > >> >> use ? (fixed pitch of course)
>
> > >> >> There are some older warriors on the field (20 - 25) years, and it
> > >> >> seems that there props don't have the bite that the new warrior (10
> > >> >> years old) does.
>
> > >> >No, but years of wear and dressing the prop because of nicks and what not
> > >> >doesn't do them any good at all.
>
> > >> >Bertie
>
> > >> I have a fibreglass covered wooden prop which makes it reasonably
> > >> resilient in light rain. I paint it.
> > >> when the aforesaid light rain has eroded the paint *near the leading
> > >> edge I lose 5 knots in cruise speed.
>
> > >> also If I alter the shape with a poor paint coat I lose cruise speed..
>
> > >> the other factor with some commercial aircraft is that there are often
> > >> 3 props approved for them. a climb, a utility and a cruise prop.
> > >> on little cessnas they are each 2 inches of pitch apart.
> > >> memories of cruise with a cruise prop would make cruise on a climb
> > >> prop seem quite anaemic.
>
> > >> ....and what bertie wrote.
>
> > >> Stealth Pilot
>
> > >I can understand why a poor -- as in not smooth -- paint job would
> > >alter the prop's efficiency, but never would have guessed having a
> > >fractional mm of paint ablated from the leading edge of the prop would
> > >affect it that much. Tongue in cheek question -- did the natural color
> > >of the prop clash with that color and scare the air, or something?
>
> > >On a serious note, have you any thoughts as to why such a minor change
> > >in shape would have such a remarkable change in efficiency? A 5 knot
> > >change in airspeed is like reducing the manifold an inch or so, isn't
> > >it? That's huge! It also suggests there may be very minor changes in
> > >prop that could improve performance too.
>
> > >l
>
> > the prop had a fairly average sheath put on it. average workmanship.
> > I use the paint layers to fair the surface to a smoother shape.
> > the face I see is painted matte black to make it invisible.
> > the leading edge is blue, the rest varnish.
> > chipped paint just creates a turbulator which seems to affect this
> > blade section. (clark Y, aka naca 44xx series)
>
> > I got 5 extra knots in cruise for nothing when I cleaned up the prop
> > and got the shape right the first time. the damaged leading edge paint
> > just drops me back to the original slower cruise.
>
> > Stealth Pilot
>
> Five knots is a huge gain. I remember reading some years ago of a
> homebuilt getting a new paint job, and the color change on the wings
> led to a paint 'bump' or seam near the leading edge which so altered
> the airflow the airplane could not fly (probably changed the
> stagnation line).

Sounds like a myth to me. How thick is a paint line?

> Still, that big a change in cruise speed seems
> remarkable.

I'd say unlikely.

Cheers
>

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in news:dt4ek.20332$%q.3231
@newsfe24.lga:

>
> "More_Flaps" > wrote in message
> ...
>
> I'd say unlikely.
>
> Cheers
>>
>
> Or hallucination.
>
>

Your an hullucination?


I thought you were more sort of a bad dream. the kind you have whne you eat
too many chilli dogs.


Bertie

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in news:cr4ek.20329$%q.13939
@newsfe24.lga:

>
> "Stealth Pilot" > wrote in message
> ...
>
> Major bull**** snip _>
>
>>
>> Stealth Pilot
>>
>>
>
> What a crock of ****.
>
>
>

Really?

Care to argue it out Orville?


Bertie

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in news:1s4ek.20330$%q.9276
@newsfe24.lga:

>
> "Stealth Pilot" > wrote in message
> ...
>>
>> I got 5 extra knots in cruise for nothing when I cleaned up the prop
>> and got the shape right the first time. the damaged leading edge paint
>> just drops me back to the original slower cruise.
>>
>> Stealth Pilot
>
> Only if you are on drugs.
>
>
>

I'll have to take your expert word on that, there.


Bertie

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in news:Gs4ek.20331$%q.18606
@newsfe24.lga:

>
> "Stealth Pilot" > wrote in message
> ...
>
> You don't need a prop, you need a new ASI.
>
>
>

You don't need those drugs, Maxie, you just need a bit of electro shock.
Try sticking your tongue in a light socket.
You'll not only enjoy it, you'll notice the difference n your outlook in a
matter of days, if not hours.


Bertie

[Bertie the Bunyip[_24_]]

More_Flaps > wrote in
:

> On Jul 13, 12:53*am, wrote:
>> On Jul 12, 8:37*am, Stealth Pilot >
>> wrote:
>>
>>
>>
>> > On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote:
>> > >On Jul 11, 7:09*am, Stealth Pilot
>> > > wrote:
>> > >> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip
>> > >> <T...@ld
> .you>
>> > >> wrote:
>>
>> > >> >sid > wrote in
>> > >> >news:702f8b8d-b77e-452c-904c-
>> > >> :
>>
>> > >> >> On older planes, does the angle of attack change ? Does the
>> > >> >> prop
> angle
>> > >> >> relax like a motorboat prop does after 1 or 2 decades of
>> > >> >> constant use ? (fixed pitch of course)
>>
>> > >> >> There are some older warriors on the field (20 - 25) years,
>> > >> >> and i
> t
>> > >> >> seems that there props don't have the bite that the new
>> > >> >> warrior (
> 10
>> > >> >> years old) does.
>>
>> > >> >No, but years of wear and dressing the prop because of nicks
>> > >> >and wh
> at not
>> > >> >doesn't do them any good at all.
>>
>> > >> >Bertie
>>
>> > >> I have a fibreglass covered wooden prop which makes it
>> > >> reasonably resilient in light rain. I paint it.
>> > >> when the aforesaid light rain has eroded the paint *near the
>> > >> leadi
> ng
>> > >> edge I lose 5 knots in cruise speed.
>>
>> > >> also If I alter the shape with a poor paint coat I lose cruise
>> > >> speed
> .
>>
>> > >> the other factor with some commercial aircraft is that there are
>> > >> oft
> en
>> > >> 3 props approved for them. a climb, a utility and a cruise prop.
>> > >> on little cessnas they are each 2 inches of pitch apart.
>> > >> memories of cruise with a cruise prop would make cruise on a
>> > >> climb prop seem quite anaemic.
>>
>> > >> ....and what bertie wrote.
>>
>> > >> Stealth Pilot
>>
>> > >I can understand why a poor -- as in not smooth -- paint job would
>> > >alter the prop's efficiency, but never would have guessed having a
>> > >fractional mm of paint ablated from the leading edge of the prop
>> > >would affect it that much. Tongue in cheek question -- did the
>> > >natural color of the prop clash with that color and scare the air,
>> > >or something?
>>
>> > >On a serious note, have you any thoughts as to why such a minor
>> > >change in shape would have such a remarkable change in efficiency?
>> > >A 5 knot change in airspeed is like reducing the manifold an inch
>> > >or so, isn't it? That's huge! It also suggests there may be very
>> > >minor changes in prop that could improve performance too.
>>
>> > >l
>>
>> > the prop had a fairly average sheath put on it. average
>> > workmanship. I use the paint layers to fair the surface to a
>> > smoother shape. the face I see is painted matte black to make it
>> > invisible. the leading edge is blue, the rest varnish.
>> > chipped paint just creates a turbulator which seems to affect this
>> > blade section. (clark Y, aka naca 44xx series)
>>
>> > I got 5 extra knots in cruise for nothing when I cleaned up the
>> > prop and got the shape right the first time. the damaged leading
>> > edge paint just drops me back to the original slower cruise.
>>
>> > Stealth Pilot
>>
>> Five knots is a huge gain. I remember reading some years ago of a
>> homebuilt getting a new paint job, and the color change on the wings
>> led to a paint 'bump' or seam near the leading edge which so altered
>> the airflow the airplane could not fly (probably changed the
>> stagnation line).
>
> Sounds like a myth to me. How thick is a paint line?
>
>> Still, that big a change in cruise speed seems
>> remarkable.
>
> I'd say unlikely.

Not in an airplane like the Tailwind. A small change in somethign like a
Cherokee might not get you much, though a series of changes will get you
quite a lot evn in one of those, but something that acts more of a whole
like a talwind or a Midget mustang can be hugely affected by one single
ingredient being out.


Bertie

[Maxwell[_2_]]

"Bertie the Bunyip" > wrote in message
...
>
> Not in an airplane like the Tailwind. A small change in somethign like a
> Cherokee might not get you much, though a series of changes will get you
> quite a lot evn in one of those, but something that acts more of a whole
> like a talwind or a Midget mustang can be hugely affected by one single
> ingredient being out.
>
>

Oh hell yeah, that relative to the conversation.

Try and keep up lamer.

[Bertie the Bunyip[_24_]]

wrote in
:

> On Jul 12, 9:44*am, Stealth Pilot >
> wrote:
>> On Sat, 12 Jul 2008 05:53:59 -0700 (PDT), wrote:
>> >On Jul 12, 8:37*am, Stealth Pilot >
>> >wrote:
>> >> On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote:
>> >> >On Jul 11, 7:09*am, Stealth Pilot
>> >> > wrote:
>> >> >> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip
>> >> >> <T...@l
> d.you>
>> >> >> wrote:
>>
>> >> >> >sid > wrote in
>> >> >> >news:702f8b8d-b77e-452c-904c-
>> >> >> :
>>
>> >> >> >> On older planes, does the angle of attack change ? Does the
>> >> >> >> prop
> angle
>> >> >> >> relax like a motorboat prop does after 1 or 2 decades of
>> >> >> >> constan
> t
>> >> >> >> use ? (fixed pitch of course)
>>
>> >> >> >> There are some older warriors on the field (20 - 25) years,
>> >> >> >> and
> it
>> >> >> >> seems that there props don't have the bite that the new
>> >> >> >> warrior
> (10
>> >> >> >> years old) does.
>>
>> >> >> >No, but years of wear and dressing the prop because of nicks
>> >> >> >and w
> hat not
>> >> >> >doesn't do them any good at all.
>>
>> >> >> >Bertie
>>
>> >> >> I have a fibreglass covered wooden prop which makes it
>> >> >> reasonably resilient in light rain. I paint it.
>> >> >> when the aforesaid light rain has eroded the paint *near the
>> >> >> lead
> ing
>> >> >> edge I lose 5 knots in cruise speed.
>>
>> >> >> also If I alter the shape with a poor paint coat I lose cruise
>> >> >> spee
> d.
>>
>> >> >> the other factor with some commercial aircraft is that there
>> >> >> are of
> ten
>> >> >> 3 props approved for them. a climb, a utility and a cruise
>> >> >> prop. on little cessnas they are each 2 inches of pitch apart.
>> >> >> memories of cruise with a cruise prop would make cruise on a
>> >> >> climb prop seem quite anaemic.
>>
>> >> >> ....and what bertie wrote.
>>
>> >> >> Stealth Pilot
>>
>> >> >I can understand why a poor -- as in not smooth -- paint job
>> >> >would alter the prop's efficiency, but never would have guessed
>> >> >having a fractional mm of paint ablated from the leading edge of
>> >> >the prop woul
> d
>> >> >affect it that much. Tongue in cheek question -- did the natural
>> >> >colo
> r
>> >> >of the prop clash with that color and scare the air, or
>> >> >something?
>>
>> >> >On a serious note, have you any thoughts as to why such a minor
>> >> >chang
> e
>> >> >in shape would have such a remarkable change in efficiency? A 5
>> >> >knot change in airspeed is like reducing the manifold an inch or
>> >> >so, isn't it? That's huge! It also suggests there may be very
>> >> >minor changes in prop that could improve performance too.
>>
>> >> >l
>>
>> >> the prop had a fairly average sheath put on it. average
>> >> workmanship. I use the paint layers to fair the surface to a
>> >> smoother shape. the face I see is painted matte black to make it
>> >> invisible. the leading edge is blue, the rest varnish.
>> >> chipped paint just creates a turbulator which seems to affect this
>> >> blade section. (clark Y, aka naca 44xx series)
>>
>> >> I got 5 extra knots in cruise for nothing when I cleaned up the
>> >> prop and got the shape right the first time. the damaged leading
>> >> edge paint just drops me back to the original slower cruise.
>>
>> >> Stealth Pilot
>>
>> >Five knots is a huge gain. I remember reading some years ago of a
>> >homebuilt getting a new paint job, and the color change on the wings
>> >led to a paint 'bump' or seam near the leading edge which so altered
>> >the airflow the airplane could not fly (probably changed the
>> >stagnation line). Still, that big a change in cruise speed seems
>> >remarkable.
>>
>> >In that I fly behind controllable pitch props it's nothing I'd have
>> >noticed, but still, if TLC *gains that kind of speed advantage it
>> >should be standard of care for propellers.
>>
>> I repainted the prop (and rebalanced it) and replaced the windscreen
>> plastic and saw an 11knot increase in cruise speed.
>> this is after an extensive period of taping up seams and other toying
>> that saw absolutely no improvement at all.
>>
>> it took my aero engineer friend about a month to work out what I'd
>> accidently done.
>>
>> it was ...put back all the windscreen bolts.
>>
>> this removed some blasts of air into the low pressure zone over the
>> windscreen.
>> the blasts of air were doing two things my aero engineer friend
>> deduced.
>> reducing the depression in pressure over the wing which reduced the
>> lift and required a slight increase in angle of attack which
>> increased induced drag.
>> increased the thickness of the boundary layer which increased drag.
>>
>> the jump in performance on the first flight was just stunning to
>> behold. where before I could just make 120 knots balls to the wall in
>> a flypast I can now easily achieve 145 knots at max rpm after a dive.
>>
>> your controllable prop gives you so much of an advantage.
>>
>> Stealth Pilot
>
> There are a lot of differences between the Mooney Executive and the
> 201, but the two that made the real difference in speed was a
> redesigned windscreen and a redesigned cowling. Everything else was
> pretty much lipstick but it was NOT lipstick on a pig, most agree the
> Mooney 201 was a pretty airplane in its day. I don't think the Mooney
> brothers overlooked much, but I'll take a close look to be sure things
> are still smooth where they should be.
>

mooney brothers?

Al had a brother?


Bertie

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in news:HJ6ek.20342$%q.16151
@newsfe24.lga:

>
> "Bertie the Bunyip" > wrote in message
> ...
>>
>> Not in an airplane like the Tailwind. A small change in somethign like a
>> Cherokee might not get you much, though a series of changes will get you
>> quite a lot evn in one of those, but something that acts more of a whole
>> like a talwind or a Midget mustang can be hugely affected by one single
>> ingredient being out.
>>
>>
>
> Oh hell yeah, that relative to the conversation.
>
> Try and keep up lamer.
>
>
>

Snort!

I'm so far ahead of you i know what you had for lunch next thursday.

It will be Spaghetti-ohs, BTW

Bertie

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in news:TT6ek.20347$%q.3801
@newsfe24.lga:

>
> "Bertie the Bunyip" > wrote in message
> ...
>> "Maxwell" <luv2^fly99@cox.^net> wrote in news:cr4ek.20329$%q.13939
>> @newsfe24.lga:
>>
>>>
>>> "Stealth Pilot" > wrote in message
>>> ...
>>>
>>> Major bull**** snip _>
>>>
>>>>
>>>> Stealth Pilot
>>>>
>>>>
>>>
>>> What a crock of ****.
>>>
>>>
>>>
>>
>> Really?
>>
>> Care to argue it out Orville?
>>
>>
>> Bertie
>
> Can't argue with a liar.
>

Translation. Won't argue because you can't.


Evasion noted.



Bertie

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in
:

>
> "Bertie the Bunyip" > wrote in message
> ...
>>
>> You don't need those drugs, Maxie, you just need a bit of electro
>> shock. Try sticking your tongue in a light socket.
>> You'll not only enjoy it, you'll notice the difference n your outlook
>> in a matter of days, if not hours.
>>
>>
>> Bertie
>
> Sounds like the voice of experience to me.
>
> Now we know the rest of the story. Good day!
>
>

Awww, IKYABWAI lames.


You adorable!


Bertie

[Maxwell[_2_]]

"Bertie the Bunyip" > wrote in message
...
> "Maxwell" <luv2^fly99@cox.^net> wrote in news:cr4ek.20329$%q.13939
> @newsfe24.lga:
>
>>
>> "Stealth Pilot" > wrote in message
>> ...
>>
>> Major bull**** snip _>
>>
>>>
>>> Stealth Pilot
>>>
>>>
>>
>> What a crock of ****.
>>
>>
>>
>
> Really?
>
> Care to argue it out Orville?
>
>
> Bertie

Can't argue with a liar.

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in news:UV6ek.20349$%q.12918
@newsfe24.lga:

>
> "Bertie the Bunyip" > wrote in message
> ...
>>
>> Snort!
>>
>> I'm so far ahead of you i know what you had for lunch next thursday.
>>
>> It will be Spaghetti-ohs, BTW
>>
>> Bertie
>
> You're a legend in your own mind.
>

Yep.


Bertie
>

[Maxwell[_2_]]

"Bertie the Bunyip" > wrote in message
...
>
> You don't need those drugs, Maxie, you just need a bit of electro shock.
> Try sticking your tongue in a light socket.
> You'll not only enjoy it, you'll notice the difference n your outlook in a
> matter of days, if not hours.
>
>
> Bertie

Sounds like the voice of experience to me.

Now we know the rest of the story. Good day!

[Maxwell[_2_]]

"Bertie the Bunyip" > wrote in message
...
>
> Snort!
>
> I'm so far ahead of you i know what you had for lunch next thursday.
>
> It will be Spaghetti-ohs, BTW
>
> Bertie

You're a legend in your own mind.

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in news:SZ6ek.20352$%q.4000
@newsfe24.lga:

>
> "Bertie the Bunyip" > wrote in message
> .. .
>
>>>
>>> Can't argue with a liar.
>>>
>>
>> Translation. Won't argue because you can't.
>>
>>
>> Evasion noted.
>>
>>
>>
>> Bertie
>
> Where you get this one, MX?


Evasion noted.

Bertie

[Maxwell[_2_]]

"Bertie the Bunyip" > wrote in message
.. .

>>
>> Can't argue with a liar.
>>
>
> Translation. Won't argue because you can't.
>
>
> Evasion noted.
>
>
>
> Bertie

Where you get this one, MX?

[Rich Ahrens[_2_]]

on 7/12/2008 1:39 PM Bertie the Bunyip said the following:
> "Maxwell" <luv2^fly99@cox.^net> wrote in
> :
>
>> "Bertie the Bunyip" > wrote in message
>> ...
>>> You don't need those drugs, Maxie, you just need a bit of electro
>>> shock. Try sticking your tongue in a light socket.
>>> You'll not only enjoy it, you'll notice the difference n your outlook
>>> in a matter of days, if not hours.
>>>
>>>
>>> Bertie
>> Sounds like the voice of experience to me.
>>
>> Now we know the rest of the story. Good day!
>>
> Awww, IKYABWAI lames.
>
> You adorable!

You have quite the chewtoy there, Bertie! I think you can set the drag
on high with this one and he won't throw the hook.

[Rich Ahrens[_2_]]

on 7/12/2008 1:22 PM Bertie the Bunyip said the following:
> "Maxwell" <luv2^fly99@cox.^net> wrote in news:dt4ek.20332$%q.3231
> @newsfe24.lga:
>
>> "More_Flaps" > wrote in message
>> ...
>>
>> I'd say unlikely.
>>
>> Cheers
>> Or hallucination.
>>
>>
>
> Your an hullucination?
>
>
> I thought you were more sort of a bad dream. the kind you have whne you eat
> too many chilli dogs.

He's more like what you find in the bowl the next morning after all
those chili dogs...

[More_Flaps]

On Jul 13, 6:25*am, Bertie the Bunyip > wrote:
> More_Flaps > wrote :
>
>
>
> > On Jul 13, 12:53*am, wrote:
> >> On Jul 12, 8:37*am, Stealth Pilot >
> >> wrote:
>
> >> > On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote:
> >> > >On Jul 11, 7:09*am, Stealth Pilot
> >> > > wrote:
> >> > >> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip
> >> > >> <T...@ld
> > .you>
> >> > >> wrote:
>
> >> > >> >sid > wrote in
> >> > >> >news:702f8b8d-b77e-452c-904c-
> >> > >> :
>
> >> > >> >> On older planes, does the angle of attack change ? Does the
> >> > >> >> prop
> > angle
> >> > >> >> relax like a motorboat prop does after 1 or 2 decades of
> >> > >> >> constant use ? (fixed pitch of course)
>
> >> > >> >> There are some older warriors on the field (20 - 25) years,
> >> > >> >> and i
> > t
> >> > >> >> seems that there props don't have the bite that the new
> >> > >> >> warrior (
> > 10
> >> > >> >> years old) does.
>
> >> > >> >No, but years of wear and dressing the prop because of nicks
> >> > >> >and wh
> > at not
> >> > >> >doesn't do them any good at all.
>
> >> > >> >Bertie
>
> >> > >> I have a fibreglass covered wooden prop which makes it
> >> > >> reasonably resilient in light rain. I paint it.
> >> > >> when the aforesaid light rain has eroded the paint *near the
> >> > >> leadi
> > ng
> >> > >> edge I lose 5 knots in cruise speed.
>
> >> > >> also If I alter the shape with a poor paint coat I lose cruise
> >> > >> speed
> > .
>
> >> > >> the other factor with some commercial aircraft is that there are
> >> > >> oft
> > en
> >> > >> 3 props approved for them. a climb, a utility and a cruise prop.
> >> > >> on little cessnas they are each 2 inches of pitch apart.
> >> > >> memories of cruise with a cruise prop would make cruise on a
> >> > >> climb prop seem quite anaemic.
>
> >> > >> ....and what bertie wrote.
>
> >> > >> Stealth Pilot
>
> >> > >I can understand why a poor -- as in not smooth -- paint job would
> >> > >alter the prop's efficiency, but never would have guessed having a
> >> > >fractional mm of paint ablated from the leading edge of the prop
> >> > >would affect it that much. Tongue in cheek question -- did the
> >> > >natural color of the prop clash with that color and scare the air,
> >> > >or something?
>
> >> > >On a serious note, have you any thoughts as to why such a minor
> >> > >change in shape would have such a remarkable change in efficiency?
> >> > >A 5 knot change in airspeed is like reducing the manifold an inch
> >> > >or so, isn't it? That's huge! It also suggests there may be very
> >> > >minor changes in prop that could improve performance too.
>
> >> > >l
>
> >> > the prop had a fairly average sheath put on it. average
> >> > workmanship. I use the paint layers to fair the surface to a
> >> > smoother shape. the face I see is painted matte black to make it
> >> > invisible. the leading edge is blue, the rest varnish.
> >> > chipped paint just creates a turbulator which seems to affect this
> >> > blade section. (clark Y, aka naca 44xx series)
>
> >> > I got 5 extra knots in cruise for nothing when I cleaned up the
> >> > prop and got the shape right the first time. the damaged leading
> >> > edge paint just drops me back to the original slower cruise.
>
> >> > Stealth Pilot
>
> >> Five knots is a huge gain. I remember reading some years ago of a
> >> homebuilt getting a new paint job, and the color change on the wings
> >> led to a paint 'bump' or seam near the leading edge which so altered
> >> the airflow the airplane could not fly (probably changed the
> >> stagnation line).
>
> > Sounds like a myth to me. How thick is a paint line?
>
> >> Still, that big a change in cruise speed seems
> >> remarkable.
>
> > I'd say unlikely.
>
> Not in an airplane like the Tailwind. A small change in somethign like a
> Cherokee might not get you much, though a series of changes will get you
> quite a lot evn in one of those, but something that acts more of a whole
> like a talwind or a Midget mustang can be hugely affected by one single
> ingredient being out.
>
Sure but becoming unflyable due to a paintline?
Cheers

[Bertie the Bunyip[_24_]]

More_Flaps > wrote in
:

> On Jul 13, 6:25*am, Bertie the Bunyip > wrote:
>> More_Flaps > wrote
>> innews:85401967-9d5c-45a1-b9e1-a61
> :
>>
>>
>>
>> > On Jul 13, 12:53*am, wrote:
>> >> On Jul 12, 8:37*am, Stealth Pilot
>> >> > wrote:
>>
>> >> > On Fri, 11 Jul 2008 06:00:22 -0700 (PDT),
>> >> > wrote:
>> >> > >On Jul 11, 7:09*am, Stealth Pilot
>> >> > > wrote:
>> >> > >> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip
>> >> > >> <T...@ld
>> > .you>
>> >> > >> wrote:
>>
>> >> > >> >sid > wrote in
>> >> > >> >news:702f8b8d-b77e-452c-904c-
>> >> > >> :
>>
>> >> > >> >> On older planes, does the angle of attack change ? Does
>> >> > >> >> the prop
>> > angle
>> >> > >> >> relax like a motorboat prop does after 1 or 2 decades of
>> >> > >> >> constant use ? (fixed pitch of course)
>>
>> >> > >> >> There are some older warriors on the field (20 - 25)
>> >> > >> >> years, and i
>> > t
>> >> > >> >> seems that there props don't have the bite that the new
>> >> > >> >> warrior (
>> > 10
>> >> > >> >> years old) does.
>>
>> >> > >> >No, but years of wear and dressing the prop because of nicks
>> >> > >> >and wh
>> > at not
>> >> > >> >doesn't do them any good at all.
>>
>> >> > >> >Bertie
>>
>> >> > >> I have a fibreglass covered wooden prop which makes it
>> >> > >> reasonably resilient in light rain. I paint it.
>> >> > >> when the aforesaid light rain has eroded the paint *near the
>> >> > >> leadi
>> > ng
>> >> > >> edge I lose 5 knots in cruise speed.
>>
>> >> > >> also If I alter the shape with a poor paint coat I lose
>> >> > >> cruise speed
>> > .
>>
>> >> > >> the other factor with some commercial aircraft is that there
>> >> > >> are oft
>> > en
>> >> > >> 3 props approved for them. a climb, a utility and a cruise
>> >> > >> prop. on little cessnas they are each 2 inches of pitch
>> >> > >> apart. memories of cruise with a cruise prop would make
>> >> > >> cruise on a climb prop seem quite anaemic.
>>
>> >> > >> ....and what bertie wrote.
>>
>> >> > >> Stealth Pilot
>>
>> >> > >I can understand why a poor -- as in not smooth -- paint job
>> >> > >would alter the prop's efficiency, but never would have guessed
>> >> > >having a fractional mm of paint ablated from the leading edge
>> >> > >of the prop would affect it that much. Tongue in cheek question
>> >> > >-- did the natural color of the prop clash with that color and
>> >> > >scare the air, or something?
>>
>> >> > >On a serious note, have you any thoughts as to why such a minor
>> >> > >change in shape would have such a remarkable change in
>> >> > >efficiency? A 5 knot change in airspeed is like reducing the
>> >> > >manifold an inch or so, isn't it? That's huge! It also suggests
>> >> > >there may be very minor changes in prop that could improve
>> >> > >performance too.
>>
>> >> > >l
>>
>> >> > the prop had a fairly average sheath put on it. average
>> >> > workmanship. I use the paint layers to fair the surface to a
>> >> > smoother shape. the face I see is painted matte black to make it
>> >> > invisible. the leading edge is blue, the rest varnish.
>> >> > chipped paint just creates a turbulator which seems to affect
>> >> > this blade section. (clark Y, aka naca 44xx series)
>>
>> >> > I got 5 extra knots in cruise for nothing when I cleaned up the
>> >> > prop and got the shape right the first time. the damaged leading
>> >> > edge paint just drops me back to the original slower cruise.
>>
>> >> > Stealth Pilot
>>
>> >> Five knots is a huge gain. I remember reading some years ago of a
>> >> homebuilt getting a new paint job, and the color change on the
>> >> wings led to a paint 'bump' or seam near the leading edge which so
>> >> altered the airflow the airplane could not fly (probably changed
>> >> the stagnation line).
>>
>> > Sounds like a myth to me. How thick is a paint line?
>>
>> >> Still, that big a change in cruise speed seems
>> >> remarkable.
>>
>> > I'd say unlikely.
>>
>> Not in an airplane like the Tailwind. A small change in somethign
>> like a Cherokee might not get you much, though a series of changes
>> will get you quite a lot evn in one of those, but something that acts
>> more of a whole like a talwind or a Midget mustang can be hugely
>> affected by one single ingredient being out.
>>
> Sure but becoming unflyable due to a paintline?
> Cheers
> #

Oh sorry, i thought you were talking about the improvements on the
tailwind. Never heard of anything like that before
>

[Bertie the Bunyip[_25_]]

Rich Ahrens > wrote in
. net:

> on 7/12/2008 1:22 PM Bertie the Bunyip said the following:
>> "Maxwell" <luv2^fly99@cox.^net> wrote in news:dt4ek.20332$%q.3231
>> @newsfe24.lga:
>>
>>> "More_Flaps" > wrote in message
>>>
>>> ...
>>>
>>> I'd say unlikely.
>>>
>>> Cheers
>>> Or hallucination.
>>>
>>>
>>
>> Your an hullucination?
>>
>>
>> I thought you were more sort of a bad dream. the kind you have whne
>> you eat too many chilli dogs.
>
> He's more like what you find in the bowl the next morning after all
> those chili dogs...
>

Unfortunately, that's no hallucination.


Bertie

[Bertie the Bunyip[_25_]]

Rich Ahrens > wrote in news:48790786$0$60071
:

> on 7/12/2008 1:39 PM Bertie the Bunyip said the following:
>> "Maxwell" <luv2^fly99@cox.^net> wrote in
>> :
>>
>>> "Bertie the Bunyip" > wrote in message
>>> ...
>>>> You don't need those drugs, Maxie, you just need a bit of electro
>>>> shock. Try sticking your tongue in a light socket.
>>>> You'll not only enjoy it, you'll notice the difference n your outlook
>>>> in a matter of days, if not hours.
>>>>
>>>>
>>>> Bertie
>>> Sounds like the voice of experience to me.
>>>
>>> Now we know the rest of the story. Good day!
>>>
>> Awww, IKYABWAI lames.
>>
>> You adorable!
>
> You have quite the chewtoy there, Bertie! I think you can set the drag
> on high with this one and he won't throw the hook.
>

Absolutely. You don't get one like this every day!

Bertie

[Maxwell[_2_]]

"Bertie the Bunyip" > wrote in message
...

>
> Oh sorry, i thought you were talking about the improvements on the
> tailwind. Never heard of anything like that before
>>
>

Try to keep up dumb ass.

[Bertie the Bunyip[_25_]]

"Maxwell" <luv2^fly99@cox.^net> wrote in news:ADaek.20360$%q.1443
@newsfe24.lga:

>
> "Bertie the Bunyip" > wrote in message
> ...
>
>>
>> Oh sorry, i thought you were talking about the improvements on the
>> tailwind. Never heard of anything like that before
>>>
>>
>
> Try to keep up dumb ass.
>
>
>

Do give us a dissertation on efficiency luser boi.



Bertie

[Stealth Pilot[_2_]]

On Sat, 12 Jul 2008 08:45:36 -0700 (PDT), More_Flaps
> wrote:

>On Jul 13, 12:53*am, wrote:
>> On Jul 12, 8:37*am, Stealth Pilot >
>> wrote:
>>
>>
>>
>> > On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote:
>> > >On Jul 11, 7:09*am, Stealth Pilot >
>> > >wrote:
>> > >> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip >
>> > >> wrote:
>>
>> > >> >sid > wrote in news:702f8b8d-b77e-452c-904c-
>> > >> :
>>
>> > >> >> On older planes, does the angle of attack change ? Does the prop angle
>> > >> >> relax like a motorboat prop does after 1 or 2 decades of constant
>> > >> >> use ? (fixed pitch of course)
>>
>> > >> >> There are some older warriors on the field (20 - 25) years, and it
>> > >> >> seems that there props don't have the bite that the new warrior (10
>> > >> >> years old) does.
>>
>> > >> >No, but years of wear and dressing the prop because of nicks and what not
>> > >> >doesn't do them any good at all.
>>
>> > >> >Bertie
>>
>> > >> I have a fibreglass covered wooden prop which makes it reasonably
>> > >> resilient in light rain. I paint it.
>> > >> when the aforesaid light rain has eroded the paint *near the leading
>> > >> edge I lose 5 knots in cruise speed.
>>
>> > >> also If I alter the shape with a poor paint coat I lose cruise speed.
>>
>> > >> the other factor with some commercial aircraft is that there are often
>> > >> 3 props approved for them. a climb, a utility and a cruise prop.
>> > >> on little cessnas they are each 2 inches of pitch apart.
>> > >> memories of cruise with a cruise prop would make cruise on a climb
>> > >> prop seem quite anaemic.
>>
>> > >> ....and what bertie wrote.
>>
>> > >> Stealth Pilot
>>
>> > >I can understand why a poor -- as in not smooth -- paint job would
>> > >alter the prop's efficiency, but never would have guessed having a
>> > >fractional mm of paint ablated from the leading edge of the prop would
>> > >affect it that much. Tongue in cheek question -- did the natural color
>> > >of the prop clash with that color and scare the air, or something?
>>
>> > >On a serious note, have you any thoughts as to why such a minor change
>> > >in shape would have such a remarkable change in efficiency? A 5 knot
>> > >change in airspeed is like reducing the manifold an inch or so, isn't
>> > >it? That's huge! It also suggests there may be very minor changes in
>> > >prop that could improve performance too.
>>
>> > >l
>>
>> > the prop had a fairly average sheath put on it. average workmanship.
>> > I use the paint layers to fair the surface to a smoother shape.
>> > the face I see is painted matte black to make it invisible.
>> > the leading edge is blue, the rest varnish.
>> > chipped paint just creates a turbulator which seems to affect this
>> > blade section. (clark Y, aka naca 44xx series)
>>
>> > I got 5 extra knots in cruise for nothing when I cleaned up the prop
>> > and got the shape right the first time. the damaged leading edge paint
>> > just drops me back to the original slower cruise.
>>
>> > Stealth Pilot
>>
>> Five knots is a huge gain. I remember reading some years ago of a
>> homebuilt getting a new paint job, and the color change on the wings
>> led to a paint 'bump' or seam near the leading edge which so altered
>> the airflow the airplane could not fly (probably changed the
>> stagnation line).
>
>Sounds like a myth to me. How thick is a paint line?
>

not a myth at all. it was a well documented problem on one of the
early fibreglass canards. the addition of a decorative tape stripe on
the top of the canard resulted in the aircraft not being able to
takeoff. removal of the stripe fixed the problem.

in an allied situation a friend complained of a sudden 45 knot
reduction in the speed of his RV6. it really put the wind up him.
a cursory inspection and I could see that the heavyweight polyurethane
protective tape he'd applied to the prop had destroyed the aerofoil
shape. he removed it at my suggestion and immediately had his 45 knots
back.

remember being told to remove frost from the wings before flight?
more than one aircraft has crashed because they didnt.

same effect.

Stealth Pilot

[Stealth Pilot[_2_]]

On Sat, 12 Jul 2008 18:25:42 +0000 (UTC), Bertie the Bunyip >
wrote:


>>> > I got 5 extra knots in cruise for nothing when I cleaned up the
>>> > prop and got the shape right the first time. the damaged leading
>>> > edge paint just drops me back to the original slower cruise.
>>>
>>> > Stealth Pilot
>>>
>>> Five knots is a huge gain. I remember reading some years ago of a
>>> homebuilt getting a new paint job, and the color change on the wings
>>> led to a paint 'bump' or seam near the leading edge which so altered
>>> the airflow the airplane could not fly (probably changed the
>>> stagnation line).
>>
>> Sounds like a myth to me. How thick is a paint line?
>>
>>> Still, that big a change in cruise speed seems
>>> remarkable.
>>
>> I'd say unlikely.
>
>Not in an airplane like the Tailwind. A small change in somethign like a
>Cherokee might not get you much, though a series of changes will get you
>quite a lot evn in one of those, but something that acts more of a whole
>like a talwind or a Midget mustang can be hugely affected by one single
>ingredient being out.
>
>
>Bertie

on an allied note there was a cherokee that had been flown up in the
North of Australia all it's life. every year to protect the aircraft
the owner had hand painted it. the paint eventually looked so crappy
that when it was sold the new owner immediately put it into the paint
shop.

the painters were intrigued by the thickness of the paint. on careful
examination made easier because each year it was painted a new colour
the painters discovered that it had 26 distinct layers of paint.
needless to say the professional paint job removed all of this re
alodined the skin and applied the thin paint coats.

the new owner reported that after repainting it felt like the aircraft
had an extra 50 horsepower.

paint matters.

Stealth Pilot

[Stealth Pilot[_2_]]

On Sat, 12 Jul 2008 13:41:49 -0500, "Maxwell" <luv2^fly99@cox.^net>
wrote:

>
>"Bertie the Bunyip" > wrote in message
...
>>
>> Snort!
>>
>> I'm so far ahead of you i know what you had for lunch next thursday.
>>
>> It will be Spaghetti-ohs, BTW
>>
>> Bertie
>
>You're a legend in your own mind.
>

maxwell you are such a dimwit that if bertie was as thick as two short
planks he'd still be brilliant compared to you.
god you're a f@@@@@@t.

Stealth pilot

[Bertie the Bunyip[_24_]]

Stealth Pilot > wrote in
:

> On Sat, 12 Jul 2008 18:25:42 +0000 (UTC), Bertie the Bunyip >
> wrote:
>
>
>>>> > I got 5 extra knots in cruise for nothing when I cleaned up the
>>>> > prop and got the shape right the first time. the damaged leading
>>>> > edge paint just drops me back to the original slower cruise.
>>>>
>>>> > Stealth Pilot
>>>>
>>>> Five knots is a huge gain. I remember reading some years ago of a
>>>> homebuilt getting a new paint job, and the color change on the
wings
>>>> led to a paint 'bump' or seam near the leading edge which so
altered
>>>> the airflow the airplane could not fly (probably changed the
>>>> stagnation line).
>>>
>>> Sounds like a myth to me. How thick is a paint line?
>>>
>>>> Still, that big a change in cruise speed seems
>>>> remarkable.
>>>
>>> I'd say unlikely.
>>
>>Not in an airplane like the Tailwind. A small change in somethign like
a
>>Cherokee might not get you much, though a series of changes will get
you
>>quite a lot evn in one of those, but something that acts more of a
whole
>>like a talwind or a Midget mustang can be hugely affected by one
single
>>ingredient being out.
>>
>>
>>Bertie
>
> on an allied note there was a cherokee that had been flown up in the
> North of Australia all it's life. every year to protect the aircraft
> the owner had hand painted it. the paint eventually looked so crappy
> that when it was sold the new owner immediately put it into the paint
> shop.
>
> the painters were intrigued by the thickness of the paint. on careful
> examination made easier because each year it was painted a new colour
> the painters discovered that it had 26 distinct layers of paint.
> needless to say the professional paint job removed all of this re
> alodined the skin and applied the thin paint coats.
>
> the new owner reported that after repainting it felt like the aircraft
> had an extra 50 horsepower.
>
> paint matters.

On a prop, definitely. I'm sure the thing was getting a substantial
boost in HP if the revs were down static!

Bertie
>

[Bertie the Bunyip[_24_]]

Stealth Pilot > wrote in
:

> On Sat, 12 Jul 2008 08:45:36 -0700 (PDT), More_Flaps
> > wrote:
>
>>On Jul 13, 12:53*am, wrote:
>>> On Jul 12, 8:37*am, Stealth Pilot >
>>> wrote:
>>>
>>>
>>>
>>> > On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote:
>>> > >On Jul 11, 7:09*am, Stealth Pilot
>>> > > wrote:
>>> > >> On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip
>>> > >> > wrote:
>>>
>>> > >> >sid > wrote in
>>> > >> >news:702f8b8d-b77e-452c-904c-
>>> > >> :
>>>
>>> > >> >> On older planes, does the angle of attack change ? Does the
>>> > >> >> prop angle relax like a motorboat prop does after 1 or 2
>>> > >> >> decades of constant use ? (fixed pitch of course)
>>>
>>> > >> >> There are some older warriors on the field (20 - 25) years,
>>> > >> >> and it seems that there props don't have the bite that the
>>> > >> >> new warrior (10 years old) does.
>>>
>>> > >> >No, but years of wear and dressing the prop because of nicks
>>> > >> >and what not doesn't do them any good at all.
>>>
>>> > >> >Bertie
>>>
>>> > >> I have a fibreglass covered wooden prop which makes it
>>> > >> reasonably resilient in light rain. I paint it.
>>> > >> when the aforesaid light rain has eroded the paint *near the
>>> > >> leading edge I lose 5 knots in cruise speed.
>>>
>>> > >> also If I alter the shape with a poor paint coat I lose cruise
>>> > >> speed.
>>>
>>> > >> the other factor with some commercial aircraft is that there
>>> > >> are often 3 props approved for them. a climb, a utility and a
>>> > >> cruise prop. on little cessnas they are each 2 inches of pitch
>>> > >> apart. memories of cruise with a cruise prop would make cruise
>>> > >> on a climb prop seem quite anaemic.
>>>
>>> > >> ....and what bertie wrote.
>>>
>>> > >> Stealth Pilot
>>>
>>> > >I can understand why a poor -- as in not smooth -- paint job
>>> > >would alter the prop's efficiency, but never would have guessed
>>> > >having a fractional mm of paint ablated from the leading edge of
>>> > >the prop would affect it that much. Tongue in cheek question --
>>> > >did the natural color of the prop clash with that color and scare
>>> > >the air, or something?
>>>
>>> > >On a serious note, have you any thoughts as to why such a minor
>>> > >change in shape would have such a remarkable change in
>>> > >efficiency? A 5 knot change in airspeed is like reducing the
>>> > >manifold an inch or so, isn't it? That's huge! It also suggests
>>> > >there may be very minor changes in prop that could improve
>>> > >performance too.
>>>
>>> > >l
>>>
>>> > the prop had a fairly average sheath put on it. average
>>> > workmanship. I use the paint layers to fair the surface to a
>>> > smoother shape. the face I see is painted matte black to make it
>>> > invisible. the leading edge is blue, the rest varnish.
>>> > chipped paint just creates a turbulator which seems to affect this
>>> > blade section. (clark Y, aka naca 44xx series)
>>>
>>> > I got 5 extra knots in cruise for nothing when I cleaned up the
>>> > prop and got the shape right the first time. the damaged leading
>>> > edge paint just drops me back to the original slower cruise.
>>>
>>> > Stealth Pilot
>>>
>>> Five knots is a huge gain. I remember reading some years ago of a
>>> homebuilt getting a new paint job, and the color change on the wings
>>> led to a paint 'bump' or seam near the leading edge which so altered
>>> the airflow the airplane could not fly (probably changed the
>>> stagnation line).
>>
>>Sounds like a myth to me. How thick is a paint line?
>>
>
> not a myth at all. it was a well documented problem on one of the
> early fibreglass canards. the addition of a decorative tape stripe on
> the top of the canard resulted in the aircraft not being able to
> takeoff. removal of the stripe fixed the problem.


Yeah, I remember that. On the flip side of that the additin of a turbulator
strip in the right place will enhance lift..

http://www.standardcirrus.org/Turbulators.html


Bertie