Prop Feathers and Engine Shuts down after landing????????

[AIR ADVENTURE82]

Today I was flying my Twin Comanche PA30 everything was great until after
landing. Once I had the wheels on the ground I pulled the power back to idle,
about three seconds or so after I pulled the power back the prop feathered and
the engine shut down. I let the engine cool down for about 30 min then started
the engine right up. Everything was running great. So I took off and flew
around for a while then came back to land, this time after I landed I put
the power back up to 1500 rpm, the oil temp was right below redline the oil
was at 50psi then the prop feathered and the engine shut down again. This also
happened to me yesterday. Every time I land the prop feathers and the engine
shuts down . Everythings always great until after landing. I only have 40
hours on the engine. Could anyone please help me out? Has this ever happened
to anyone before? Does anyone have any ideas on what it could be thanks for
everyone’s help.

[Wayne]

This is only a guess but may make some sense. Some CS props will go full
pitch if oil pressure is lost, others will to to minimum pitch with no oil
pressure. You said that the oil temperature was high. (an indication of low
oil level). Also how is the oil pressure just before it shuts down? Being
at idle already, full pitch could make enough drag to stall the engine.
OTOH, if the engine stalled first, the lack of oil pressure would cause the
prop to feather too. Make sure the oil is the right viscosity too. In planes
with oil inversion systems, it's important that you have the type of prop
that goes to full pitch because the pressure drop during the transition to
inverted would cause an engine overspeed if it was the type that went to
minimum pitch. Not that yours has an inversion system, but it's nice to know
which prop you have. Let me know how you make out, I will be reading the
other replies too but am curious to answer to your problem.
Wayne

"AIR ADVENTURE82" > wrote in message
...
> Today I was flying my Twin Comanche PA30 everything was great until after
> landing. Once I had the wheels on the ground I pulled the power back to
idle,
> about three seconds or so after I pulled the power back the prop feathered
and
> the engine shut down. I let the engine cool down for about 30 min then
started
> the engine right up. Everything was running great. So I took off and
flew
> around for a while then came back to land, this time after I landed I
put
> the power back up to 1500 rpm, the oil temp was right below redline the
oil
> was at 50psi then the prop feathered and the engine shut down again. This
also
> happened to me yesterday. Every time I land the prop feathers and the
engine
> shuts down . Everythings always great until after landing. I only have
40
> hours on the engine. Could anyone please help me out? Has this ever
happened
> to anyone before? Does anyone have any ideas on what it could be thanks
for
> everyone's help.
>

[Mark Astley]

Since the original poster indicated they were flying a twin, they most
definitely have a prop which feathers if oil pressure is lost, otherwise
single engine handling could become even more exciting than usual. Of
course, someone somewhere doubtless knows of a counter example. For a
single, the reverse is usually true: the prop goes to fine pitch if you lose
oil pressure.

That being said, high oil temperature and low oil pressure are definitely
clues. What's curious is that you don't see this behavior just idling. If
low oil levels were the culprit, I'd expect the same thing to happen after a
ground runup. I think it's time to talk to an A&P.

mark

"Wayne" > wrote in message
...
> This is only a guess but may make some sense. Some CS props will go
full
> pitch if oil pressure is lost, others will to to minimum pitch with no oil
> pressure. You said that the oil temperature was high. (an indication of
low
> oil level). Also how is the oil pressure just before it shuts down? Being
> at idle already, full pitch could make enough drag to stall the engine.
> OTOH, if the engine stalled first, the lack of oil pressure would cause
the
> prop to feather too. Make sure the oil is the right viscosity too. In
planes
> with oil inversion systems, it's important that you have the type of prop
> that goes to full pitch because the pressure drop during the transition to
> inverted would cause an engine overspeed if it was the type that went to
> minimum pitch. Not that yours has an inversion system, but it's nice to
know
> which prop you have. Let me know how you make out, I will be reading the
> other replies too but am curious to answer to your problem.
> Wayne
>
> "AIR ADVENTURE82" > wrote in message
> ...
> > Today I was flying my Twin Comanche PA30 everything was great until
after
> > landing. Once I had the wheels on the ground I pulled the power back to

> idle,
> > about three seconds or so after I pulled the power back the prop
feathered
> and
> > the engine shut down. I let the engine cool down for about 30 min then
> started
> > the engine right up. Everything was running great. So I took off and
> flew
> > around for a while then came back to land, this time after I landed I
> put
> > the power back up to 1500 rpm, the oil temp was right below redline the
> oil
> > was at 50psi then the prop feathered and the engine shut down again.
This
> also
> > happened to me yesterday. Every time I land the prop feathers and the
> engine
> > shuts down . Everythings always great until after landing. I only have
> 40
> > hours on the engine. Could anyone please help me out? Has this ever
> happened
> > to anyone before? Does anyone have any ideas on what it could be
thanks
> for
> > everyone's help.
> >
>
>

[Ron Natalie]

"AIR ADVENTURE82" > wrote in message ...
> Today I was flying my Twin Comanche PA30 everything was great until after
> landing.

What oil are you using? Warm temperatures and a too light weight oil can
cause low pressures.

[Ron Natalie]

"Dennis O'Connor" > wrote in message ...
> Either the prop governor, or the piston in the hub are going to hell in a
> handbasket... The engine 'stalls' when the prop goes into feather - I doubt
> that there is an engine problem... Sending the governor out for overhual
> immediately, would be my inclination...

Actually, it may just be a bad idle mixture setting. My engine when hot used
to stall at idle (frequently rolling out with the throttle at idle). I didn't have a twin,
but I can imagine that the prop would feather during such a sequence in a twin.

[C J Campbell]

Shouldn't the prop feather when you lose oil pressure (on a twin)? Sounds
like the prop is behaving normally to me. More likely you are having some
kind of problem with your throttle.

[Tony Cox]

"Dennis O'Connor" > wrote in message
...
> Either the prop governor, or the piston in the hub are going to hell in a
> handbasket... The engine 'stalls' when the prop goes into feather - I
doubt
> that there is an engine problem... Sending the governor out for overhual
> immediately, would be my inclination...
>

Could also be the collar on the crankshaft where the oil gets injected
to drive the prop. There was an article on this recently in "Light Plane
Maintenance", but I can't put my hands on it right now. If the tolerance
is a bit out, there could be a pressure loss sufficient to cause the prop
to feather.

--
Dr. Tony Cox
Citrus Controls Inc.
e-mail:
http://CitrusControls.com/

[Dennis O'Connor]

Piston props (that i have flown) don't feather during shutdown...

It's tough to diagnose a problem on a complex system like a feathering, prop
without being hands on, and without knowing the details of the feathering
mechanism of the model of prop involved, but my initial inclination is
still that it is governor or hub, not engine.... Since then I took a quick
look at the commanche prop hub, and they have a pair of locks that prevent
the blades from feathering when the rpm is below a certain rpm... Those
locks are stuck open or damaged... However, the blades still wouldn't
feather as long as the engine has enough oil pressure for the piston to
overcome the feathering spring... Since he specifically said he had oil
pressure at idle I still am very suspicious that the prop governor has an
internal leak after it gets hot...

Denny


> Actually, it may just be a bad idle mixture setting. My engine when hot
used
> to stall at idle (frequently rolling out with the throttle at idle). I
didn't have a twin,
> but I can imagine that the prop would feather during such a sequence in a
twin.

[[email protected]]

"Dennis O'Connor" > wrote in message >...
> Either the prop governor, or the piston in the hub are going to hell in a
> handbasket... The engine 'stalls' when the prop goes into feather - I doubt
> that there is an engine problem... Sending the governor out for overhual
> immediately, would be my inclination...

snip

First off, there is a mechanical high-pitch propeller stop that should
be engaged somewhere <1500 rpm and disengaged >1500 rpm. This stop
enables feathering in-flight, but should prevent it at engine
shut-down. This mechanism has rather obviously failed. How come
across it in the past several times, typically the prop feathers AFTER
the engine is shut down.

Also, if everything is working properly, the oil pressure delivered
from the prop governor to the propeller should keep the propeller
against the fixed low-pitch stop during un-"governed" operation. As
in, unless the governor is sensing the engine rpm is too high (prop
pitch too low) and starts to dump governed oil pressure, the propeller
should stay in the low pitch setting.

If the engine is not supplying sufficient oil volume to the governor,
governor will not supply sufficient pressure to the propeller.

With the propeller feathering at low/no rpm, it must be
inspected/repaired. Then the first step in diagnosing a strange
"governor" problem is ensuring that the proper amount of engine oil is
present at the governor pad. The tooling to accomplish this also makes
it easy to check the prop oil supply path from the other passage at
the governor pad through the front main bearing to the prop galley in
the crankshaft.

TC

[Ron Natalie]

> wrote in message om...

> With the propeller feathering at low/no rpm, it must be
> inspected/repaired. Then the first step in diagnosing a strange
> "governor" problem is ensuring that the proper amount of engine oil is
> present at the governor pad. The tooling to accomplish this also makes
> it easy to check the prop oil supply path from the other passage at
> the governor pad through the front main bearing to the prop galley in
> the crankshaft.
>
So how do you explain the engine stalling in addition to the feathering?

[Dennis O'Connor]

I never flew an piston engine that will continue to run at idle with a
feathered prop... Way too much load...
Denny
"Ron Natalie" > wrote in message
...
>
> > wrote in message
om...
>
> > With the propeller feathering at low/no rpm, it must be
> > inspected/repaired. Then the first step in diagnosing a strange
> > "governor" problem is ensuring that the proper amount of engine oil is
> > present at the governor pad. The tooling to accomplish this also makes
> > it easy to check the prop oil supply path from the other passage at
> > the governor pad through the front main bearing to the prop galley in
> > the crankshaft.
> >
> So how do you explain the engine stalling in addition to the feathering?
>
>

[AIR ADVENTURE82]

Thanks for everyone’s help. I was told by my A&P today to swap the governors
from the right to the left engine and take it up to see if the left engine
feathers and shuts down. Friday morning IM going to go fly and see what
happens. I have about 40 hours on the right engine. Today I also drained the
oil and flushed the engine. I cut open the oil filter and found some small
metal particles. I used a funnel with a screen when I drained the
oil and found no metal particles. I also took the screen off the governor and
found no metal particles. When I drained the fluid out of the engine I also
found no metal
particles. All the cylinders are 80/80.

By the way the engine feathered and shut down at 1000rpm,1500rpm,1700rpm,
50psi and oil temp below redline.

Thanks for everyone’s help once again and I will let everyone know what
happens

[Montblack]

Hope you don't have two separate, overlapping, problems. Yikes, now it's
both engines !! :-(

--
Montblack

("AIR ADVENTURE82" wrote)
> Thanks for everyone's help. I was told by my A&P today to swap the
governors
> from the right to the left engine and take it up to see if the left engine
> feathers and shuts down. Friday morning IM going to go fly and see what
> happens. <snip>

[[email protected]]

"Dennis O'Connor" > wrote in message >...
> Piston props (that i have flown) don't feather during shutdown...
>
> It's tough to diagnose a problem on a complex system like a feathering, prop
> without being hands on, and without knowing the details of the feathering
> mechanism of the model of prop involved, but my initial inclination is
> still that it is governor or hub, not engine.... Since then I took a quick
> look at the commanche prop hub, and they have a pair of locks that prevent
> the blades from feathering when the rpm is below a certain rpm... Those
> locks are stuck open or damaged... However, the blades still wouldn't
> feather as long as the engine has enough oil pressure for the piston to
> overcome the feathering spring... Since he specifically said he had oil
> pressure at idle I still am very suspicious that the prop governor has an
> internal leak after it gets hot...

snip

The last couple of years that I spent "in the business" I was
seriously spoiled.
All I had to do was walk 75 feet across the ramp to the prop shop
w/attached governor overhaul facility.

The gov shop had two machines, one kept with pristine "new" oil for
checking/setting overhauled governors only, the other with
"serviceable" oil, used for ops/function checking as-removed
governors. I couldn't run one myself, but saw 'em used quite often. As
you would expect, "hot" oil was used when operating the governors.

Back to the PA30 in question, I'm pretty sure that the props installed
will have compact hubs, opposed to steel hubs (with external blade
clamps and external pitch stops). On these props, the locks are
internal, working in the sorta the same fashion (weighted plungers
w/springs), engaging a notch in piston rod (connects the piston to the
yoke that twists the blades) at low/no rpm to prevent feathering on
shut-down.

As you've pointed out, a recip feathering on shut-down (or feathering
causing the shut-down) is not a "normal" situation, neither is the
lack of governed oil pressure at low rpm.

In this situation, I would have gone next door and asked the prop boys
if they could squeeze me in for a "dome job", stopped in the gov shop,
look to see if anything was bolted onto the #2 gov machine and
borrowed the gov pad plate.

Then, with the engine "hot" woulda popped the nose bowl and the gov,
installed the plate, used a differential compression tester to check
the gov-to-prop circuit, plugged it, hooked a direct reading gage to
the gov oil supply port and run that sucker noting the pressure
supplied to the pad.

Pretty simple then to carry the removed gov over and beg the gov dude
to throw it on the machine, if the machine had been "warmed up" that
day, would take about five minutes to wring the gov out.

Depending on hangar space, would probably then yank the prop to get
the dome pulled off and the locks looked at, addressing any other
issues discovered as needed.

E.T. to properly diagnose <2 hours skipping no aspects of "normal"
propeller/govenor ops. Repair time/cost variable as to what was found.

Have had various incidents over the years where a prop feathered on
shut-down. 9 times out of 10, a very careful re-start and shut-down
would result in normal ops. Often would happen again shortly
thereafter. If it feathered "twice" the prop got repaired, end of
story.

BTW, I wouldn't bet that an engine would continue to run at a "normal"
idle setting with the prop feathered, but then again I've never had
the opportunity to try it...

TC

[AIR ADVENTURE82]

Hi everyone today I took my pa30 up and went around the airport once then
landed and none of the engines feathered and shut down. So i went up for about
an hour then landed and BOTH engines feathered and shut down??????? We are
still trying to find out what this is.

[AIR ADVENTURE82]

Both engines were holding 42psi so when we checked them yesterday.

[AIR ADVENTURE82]

I just talked to the prop guy and he told me that the stop pins in both props
were very sticky and hes going to clean and lub them up. Also i had the
governor checked and it needs an overhaul.