Prop pitch cycling?

Hi!

I was told by my mechanic to only pull the prop handle until I could audibly
hear a slight pitch change to establish that it was working.

However, the aircraft manual says it should be cycled completely, and on a
cold engine three times to make sure oil is applied to the governor, or the
pitch mechanism.

Can someone elaborate on this?

What is recommended?

Thanks,

Frode

"Frode Berg" wrote in message
...
Hi!

I was told by my mechanic to only pull the prop handle until I could
audibly
hear a slight pitch change to establish that it was working.

However, the aircraft manual says it should be cycled completely, and on a
cold engine three times to make sure oil is applied to the governor, or
the
pitch mechanism.

Can someone elaborate on this?

What is recommended?

Thanks,

Frode

POH rules of course, but aside from that, I always liked to exercise a prop
through several cycles, especially when cold, just to get everything nice
and warm and fluid up there.
Dudley Henriques

The prop governor controls within a range and should hold a
steady rpm within that range. When the run-up is done at
say, 2400 rpm the prop should be cycled to the minimum rpm
and allowed to stabilize for a few seconds to check that the
governor is working properly. On a multiengine airplane the
prop should be reduced to just outside the feather detent
and allowed to run for several seconds to be sure that the
prop isn't feathering at the minimum governed speed [usually
2000 rpm on most piston engines]. If the prop control is
not rigged properly the prop will feather too soon. Then
the prop feather check should be done.

Most props have a certain amount of internal leakage to keep
warm oil circulating in the prop hub, but several cycles on
a cold engine/prop will assure that the prop does reach
proper operating temperatures.

In very cold temperatures, I like to vary the rpm every some
often to be sure the prop is functioning, but normal
internal flow should make this mostly an unneeded habit.

Remember, on a single-engine reducing rpm send oil to the
prop and on a multi, reducing rpm/feathering drain oil from
the prop.


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


"Dudley Henriques" wrote in
message
ink.net...
|
| "Frode Berg" wrote in message
| ...
| Hi!
|
| I was told by my mechanic to only pull the prop handle
until I could
| audibly
| hear a slight pitch change to establish that it was
working.
|
| However, the aircraft manual says it should be cycled
completely, and on a
| cold engine three times to make sure oil is applied to
the governor, or
| the
| pitch mechanism.
|
| Can someone elaborate on this?
|
| What is recommended?
|
| Thanks,
|
| Frode
|
| POH rules of course, but aside from that, I always liked
to exercise a prop
| through several cycles, especially when cold, just to get
everything nice
| and warm and fluid up there.
| Dudley Henriques
|
|

If all this was meant for me, I'm pretty sure I just might already know
these things
:-)
Dudley Henriques

"Jim Macklin" wrote in message
news:yZS2g.6789$ZW3.6526@dukeread04...
The prop governor controls within a range and should hold a
steady rpm within that range. When the run-up is done at
say, 2400 rpm the prop should be cycled to the minimum rpm
and allowed to stabilize for a few seconds to check that the
governor is working properly. On a multiengine airplane the
prop should be reduced to just outside the feather detent
and allowed to run for several seconds to be sure that the
prop isn't feathering at the minimum governed speed [usually
2000 rpm on most piston engines]. If the prop control is
not rigged properly the prop will feather too soon. Then
the prop feather check should be done.

Most props have a certain amount of internal leakage to keep
warm oil circulating in the prop hub, but several cycles on
a cold engine/prop will assure that the prop does reach
proper operating temperatures.

In very cold temperatures, I like to vary the rpm every some
often to be sure the prop is functioning, but normal
internal flow should make this mostly an unneeded habit.

Remember, on a single-engine reducing rpm send oil to the
prop and on a multi, reducing rpm/feathering drain oil from
the prop.


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


"Dudley Henriques" wrote in
message
ink.net...
|
| "Frode Berg" wrote in message
| ...
| Hi!
|
| I was told by my mechanic to only pull the prop handle
until I could
| audibly
| hear a slight pitch change to establish that it was
working.
|
| However, the aircraft manual says it should be cycled
completely, and on a
| cold engine three times to make sure oil is applied to
the governor, or
| the
| pitch mechanism.
|
| Can someone elaborate on this?
|
| What is recommended?
|
| Thanks,
|
| Frode
|
| POH rules of course, but aside from that, I always liked
to exercise a prop
| through several cycles, especially when cold, just to get
everything nice
| and warm and fluid up there.
| Dudley Henriques
|
|

No, I know that, I just tacked it on the thread for the
benefit of the others. I think most pilots and many
mechanics don't really understand these things, judging by
the number of twins that feather before the prop lever gets
to the gate.

If I win the lottery, odds 146 million to one, we can have
that CFI round table and sell tickets to anyone without a
CFI. CFIs can come for free. I'll pay for you and me. If I
don't win the lottery, it will have to be in Wichita, can't
afford to go elsewhere without the lottery. ;-)'

--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


"Dudley Henriques" wrote in
message
nk.net...
| If all this was meant for me, I'm pretty sure I just
might already know
| these things
| :-)
| Dudley Henriques
|
| "Jim Macklin" wrote
in message
| news:yZS2g.6789$ZW3.6526@dukeread04...
| The prop governor controls within a range and should
hold a
| steady rpm within that range. When the run-up is done
at
| say, 2400 rpm the prop should be cycled to the minimum
rpm
| and allowed to stabilize for a few seconds to check that
the
| governor is working properly. On a multiengine airplane
the
| prop should be reduced to just outside the feather
detent
| and allowed to run for several seconds to be sure that
the
| prop isn't feathering at the minimum governed speed
[usually
| 2000 rpm on most piston engines]. If the prop control
is
| not rigged properly the prop will feather too soon.
Then
| the prop feather check should be done.
|
| Most props have a certain amount of internal leakage to
keep
| warm oil circulating in the prop hub, but several cycles
on
| a cold engine/prop will assure that the prop does reach
| proper operating temperatures.
|
| In very cold temperatures, I like to vary the rpm every
some
| often to be sure the prop is functioning, but normal
| internal flow should make this mostly an unneeded habit.
|
| Remember, on a single-engine reducing rpm send oil to
the
| prop and on a multi, reducing rpm/feathering drain oil
from
| the prop.
|
|
| --
| James H. Macklin
| ATP,CFI,A&P
|
| --
| The people think the Constitution protects their rights;
| But government sees it as an obstacle to be overcome.
| some support
| http://www.usdoj.gov/olc/secondamendment2.htm
| See http://www.fija.org/ more about your rights and
duties.
|
|
| "Dudley Henriques" wrote in
| message
|
ink.net...
| |
| | "Frode Berg" wrote in message
| | ...
| | Hi!
| |
| | I was told by my mechanic to only pull the prop
handle
| until I could
| | audibly
| | hear a slight pitch change to establish that it was
| working.
| |
| | However, the aircraft manual says it should be
cycled
| completely, and on a
| | cold engine three times to make sure oil is applied
to
| the governor, or
| | the
| | pitch mechanism.
| |
| | Can someone elaborate on this?
| |
| | What is recommended?
| |
| | Thanks,
| |
| | Frode
| |
| | POH rules of course, but aside from that, I always
liked
| to exercise a prop
| | through several cycles, especially when cold, just to
get
| everything nice
| | and warm and fluid up there.
| | Dudley Henriques
| |
| |
|
|
|
|

I've done this a few times myself. :-)
On Usenet, if you underpost someone already in the thread but NOT the
original poster, what you post is considered addressed to the person you
underposted rather than simply an addition to the general thread.
Any general comment should be picked up as a post to the original poster by
clicking his/her post for reply. Then the comment appears referenced to the
initial question and not the sub poster.
I did the same thing once and gave a hundred word "lecture" on how to do a
slow roll to one of the world's best acro pilots by accidentally picking him
up to underpost instead of the initial poster who had asked about rolls. :-)
The pilot I gave the lecture to simply gave me a one word reply "Thanks"
with a smilie attached :-)
That get together sounds like fun. I'll bring the bottle!
Dudley



"Jim Macklin" wrote in message
news:nZT2g.6827$ZW3.3603@dukeread04...
No, I know that, I just tacked it on the thread for the
benefit of the others. I think most pilots and many
mechanics don't really understand these things, judging by
the number of twins that feather before the prop lever gets
to the gate.

If I win the lottery, odds 146 million to one, we can have
that CFI round table and sell tickets to anyone without a
CFI. CFIs can come for free. I'll pay for you and me. If I
don't win the lottery, it will have to be in Wichita, can't
afford to go elsewhere without the lottery. ;-)'

--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


"Dudley Henriques" wrote in
message
nk.net...
| If all this was meant for me, I'm pretty sure I just
might already know
| these things
| :-)
| Dudley Henriques
|
| "Jim Macklin" wrote
in message
| news:yZS2g.6789$ZW3.6526@dukeread04...
| The prop governor controls within a range and should
hold a
| steady rpm within that range. When the run-up is done
at
| say, 2400 rpm the prop should be cycled to the minimum
rpm
| and allowed to stabilize for a few seconds to check that
the
| governor is working properly. On a multiengine airplane
the
| prop should be reduced to just outside the feather
detent
| and allowed to run for several seconds to be sure that
the
| prop isn't feathering at the minimum governed speed
[usually
| 2000 rpm on most piston engines]. If the prop control
is
| not rigged properly the prop will feather too soon.
Then
| the prop feather check should be done.
|
| Most props have a certain amount of internal leakage to
keep
| warm oil circulating in the prop hub, but several cycles
on
| a cold engine/prop will assure that the prop does reach
| proper operating temperatures.
|
| In very cold temperatures, I like to vary the rpm every
some
| often to be sure the prop is functioning, but normal
| internal flow should make this mostly an unneeded habit.
|
| Remember, on a single-engine reducing rpm send oil to
the
| prop and on a multi, reducing rpm/feathering drain oil
from
| the prop.
|
|
| --
| James H. Macklin
| ATP,CFI,A&P
|
| --
| The people think the Constitution protects their rights;
| But government sees it as an obstacle to be overcome.
| some support
| http://www.usdoj.gov/olc/secondamendment2.htm
| See http://www.fija.org/ more about your rights and
duties.
|
|
| "Dudley Henriques" wrote in
| message
|
ink.net...
| |
| | "Frode Berg" wrote in message
| | ...
| | Hi!
| |
| | I was told by my mechanic to only pull the prop
handle
| until I could
| | audibly
| | hear a slight pitch change to establish that it was
| working.
| |
| | However, the aircraft manual says it should be
cycled
| completely, and on a
| | cold engine three times to make sure oil is applied
to
| the governor, or
| | the
| | pitch mechanism.
| |
| | Can someone elaborate on this?
| |
| | What is recommended?
| |
| | Thanks,
| |
| | Frode
| |
| | POH rules of course, but aside from that, I always
liked
| to exercise a prop
| | through several cycles, especially when cold, just to
get
| everything nice
| | and warm and fluid up there.
| | Dudley Henriques
| |
| |
|
|
|
|

Jim Macklin wrote:

No, I know that, I just tacked it on the thread for the
benefit of the others. I think most pilots and many
mechanics don't really understand these things, judging by
the number of twins that feather before the prop lever gets
to the gate.

Thanks, Jim, for the added information. That's how I read your post; not
a correction to Dudley's, but rather an addendum for us less knowledgeable.

--
Peter

Jim Macklin wrote:

snip/
Remember, on a single-engine, reducing rpm sends oil to the
prop and on a multi, reducing rpm/feathering drains oil from
the prop.



Well, generally this is true, but not always. Hamilton Standard
Hydro-Matic props, as used on the big radials, pump high pressure oil
*into* the hub for feathering. If you have complete oil loss, or let
the oil get too hot (and thin), you're out of luck for feathering.

Happy Flying!
Scott Skylane

That's is true, but except for the Beech 18, are there any
HS props on an airplane under 12,500 pounds?

The feathering on the HS is a electrical relay that turns on
a high pressure pump that operates at a pressure above
governor pressure. The Prop is feathered and the pump shuts
off. To unfeather the button is held in so the pump
continues to run and that causes the internal valve to move,
re-routing the oil so it unfeathers.

I wonder many pilots will take this to heart and open their
POH to the systems section?


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


"Scott Skylane" wrote in message
...
| Jim Macklin wrote:
|
| snip/
| Remember, on a single-engine, reducing rpm sends oil to
the
| prop and on a multi, reducing rpm/feathering drains oil
from
| the prop.
|
|
|
| Well, generally this is true, but not always. Hamilton
Standard
| Hydro-Matic props, as used on the big radials, pump high
pressure oil
| *into* the hub for feathering. If you have complete oil
loss, or let
| the oil get too hot (and thin), you're out of luck for
feathering.
|
| Happy Flying!
| Scott Skylane
|

"Jim Macklin" wrote in message
news:nqW2g.7077$ZW3.4090@dukeread04...
That's is true, but except for the Beech 18, are there any
HS props on an airplane under 12,500 pounds?

The feathering on the HS is a electrical relay that turns on
a high pressure pump that operates at a pressure above
governor pressure. The Prop is feathered and the pump shuts
off. To unfeather the button is held in so the pump
continues to run and that causes the internal valve to move,
re-routing the oil so it unfeathers.

I wonder many pilots will take this to heart and open their
POH to the systems section?


--
James H. Macklin
ATP,CFI,A&P

Oh for the simple life of fighters!! :-) I used Hamilton Standard props
quite a lot, but few of them feathered.
The 24D50 on my Mustang didn't feather of course :-) If I remember right,
the pitch range on my prop was something like 42 degrees.
Dudley