Prop angle of attack vs age

"Maxwell" luv2^fly99@cox.^net wrote in news:cr4ek.20329$%q.13939
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"Stealth Pilot" wrote in message
...

Major bull**** snip _


Stealth Pilot



What a crock of ****.




Really?

Care to argue it out Orville?


Bertie

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

"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

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

"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.

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

"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

"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

"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

"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.