Prop angle of attack vs age

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

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

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

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

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.

"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

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

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

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.