A little engine trouble

"Peter Duniho" wrote:

Well, we'd only climbed a few hundred feet when something in the
airplane
started making a very strange noise.

Sorry, Pete; you fly a ...?

It might have been my imagination, but it seemed
like whenever I heard the sound, there was a little
deceleration from the airplane.

Did you happen to look at the tach or MAP during any of these events?

But somehow, it still seems like the right thing to have done.

No question.

But even if the source of the noise
turns out to be something entirely benign,

Here's hoping it's not one of those intermittent, "mystery" problems and
your mechanic spots it right away. Keep us posted.
--
Dan
C172RG at BFM

"Dan Luke" wrote in message
...
Sorry, Pete; you fly a ...?

Lake Renegade (turbocharged model).

Did you happen to look at the tach or MAP during any of these events?

No. Of course, in hindsight that might have provided useful information.
But even when the takeoff is going smoothly, I'm a "eyes outside" kind of
person (once the proper reading of the gauges has been confirmed during the
takeoff roll, of course).

In this particular situation, my mind was focused on where on the water
would be acceptable for a landing (though, frankly, the Tacoma Narrows are
not generally amenable to seaplane landings in any case, due to strong
currents through there), and on a possible landing back at TIW.

Maybe I could have had my front-seat passenger watch the gauges, to try to
correlate them with the noise. But I personally didn't have the attention
to spare. I would have either have had to keep my eyes on the engine gauges
until the noise occurred, or I would have had to hope to be able to shift my
attention quickly enough to evaluate the gauges in the short period during
which the sound occurred. Neither would have been practical to do, IMHO.

It's a pretty good argument for a data-recording engine monitor. I'll
have to think about getting one of those.

Pete

"Peter Duniho" wrote in message
...
"Dan Luke" wrote in message
...
Sorry, Pete; you fly a ...?

Lake Renegade (turbocharged model).


Now I'm envious Pete.... :-)

Rest assured, it was a good call.

As a student I aborted a takeoff due to a couple of bangs on rotation and
nearly went into the grass. Turned out to be the pax seat belt hanging out
the door. The only things damaged were my ego and my rearend from the
chewing I got from my CFI.

Hope you find the culprit and the fix isn't a bank breaker.

Marty

As a student I aborted a takeoff due to a couple of bangs on rotation and
nearly went into the grass. Turned out to be the pax seat belt hanging out
the door. The only things damaged were my ego and my rearend from the
chewing I got from my CFI.

Had something like that happen... my instructor forgot to tell me that
150's sometimes get a violent nosewheel shimmy during the takeoff
roll... well, I found that out for myself on my first solo... pushed
the power up, and a few seconds later the whole plane started
shaking... aborted the takeoff thinking it was going to come apart on
me. Course, he just tells me to keep the weight off the nose, so my
three flights were done soft-field style with the nose up as soon as
it would go.

"Peter Duniho" wrote in message
...
"Dan Luke" wrote in message
...
Sorry, Pete; you fly a ...?

Lake Renegade (turbocharged model).

Did you happen to look at the tach or MAP during any of these events?

No. Of course, in hindsight that might have provided useful information.
But even when the takeoff is going smoothly, I'm a "eyes outside" kind of
person (once the proper reading of the gauges has been confirmed during
the
takeoff roll, of course).

In this particular situation, my mind was focused on where on the water
would be acceptable for a landing (though, frankly, the Tacoma Narrows are
not generally amenable to seaplane landings in any case, due to strong
currents through there), and on a possible landing back at TIW.

Maybe I could have had my front-seat passenger watch the gauges, to try to
correlate them with the noise. But I personally didn't have the attention
to spare. I would have either have had to keep my eyes on the engine
gauges
until the noise occurred, or I would have had to hope to be able to shift
my
attention quickly enough to evaluate the gauges in the short period during
which the sound occurred. Neither would have been practical to do, IMHO.

It's a pretty good argument for a data-recording engine monitor. I'll
have to think about getting one of those.

Pete

Any idea of what your passengers were doing at the time. In my airplane (an
RV-6) there is a noticable change in the tone and volume of cockpit noise
(and vibration) either the pilot or passenger shifts his/her feet on the
floor. I know when I move my feet, so it doesn't surprise me, but when I've
got a "shifty" passenger, s/he will put me on edge for a few seconds here
and there.

Getting back to your situation, is it possible that a passenger found a neat
way to rest a hand/arm/foot/etc. that created an unusual resonance? I
realize this wouldn't have caused a power loss.

One other thing to consider is a stuck valve. Your description sounds
similar to my understanding of the symptoms of a stuck valve.

KB

"Kyle Boatright" wrote in message
...
Any idea of what your passengers were doing at the time. In my airplane
(an
RV-6) there is a noticable change in the tone and volume of cockpit noise
(and vibration) either the pilot or passenger shifts his/her feet on the
floor.

No, no idea. But I've never experienced anything like that before, and I
have often flown with passengers over the years.

The one "passenger-induced emergency" in my airplane I'm aware of is that
the front seat passenger can actually push on the yoke lever with their
feet. Oddly enough, the one passenger to show this to me (unintentionally,
of course) was the same one that a few years earlier kept messing with my
elevator trim on a nighttime flight, by repeatedly alternating the position
of his seat back (it was a clear night, he was in the back seat in a 182RG,
and he kept lowering the seat back so that he could look at the stars, and
then raising it again to look out the side and front).

One other thing to consider is a stuck valve. Your description sounds
similar to my understanding of the symptoms of a stuck valve.

Unfortunately, that's the best conclusion I've been able to come to as well.
I've never experienced a stuck valve with this engine, so I don't know what
sort of power loss to expect. I'd *think* it'd be more significant than
what I noticed, but I don't really know.

The engine just got all new exhaust valves and guides a few years ago, so if
it's an exhaust valve problem, I'll be sorely disappointed. I suppose it
could be an intake valve problem, even though they don't get the kind of
wear and tear the exhaust valves do.

Pete

"Peter Duniho" wrote in message
...

much snipped

The one "passenger-induced emergency" in my airplane I'm aware of is that
the front seat passenger can actually push on the yoke lever with their
feet. Oddly enough, the one passenger to show this to me
(unintentionally,
of course) was the same one that a few years earlier kept messing with my
elevator trim on a nighttime flight, by repeatedly alternating the
position
of his seat back (it was a clear night, he was in the back seat in a
182RG,
and he kept lowering the seat back so that he could look at the stars, and
then raising it again to look out the side and front).

Pete

Hijacking the thread here, but...

We had a fatal accident in an Ercoupe in the local area last year that
possibly/probably involved accidental control manipulation by the passenger.
Apparently, the aircraft ran out of fuel and the pilot had lined up for a
landing in a field. Most likely survivable, possibly even a field he could
have flown out of after adding fuel. However, the airplane went in almost
vertical at the "approach end" of the field. Speculation is/was that the
passenger used his feet to brace himself for the off-field landing and
unknowingly used the elevator control linkages in the footwell as a place to
brace. The harder he braced, the more the airplane pitched nose down...
Right into the ground. Two fatalities in an accident that shouldn't have
even resulted in injuries.

KB

On Mon, 14 Jun 2004 16:39:51 -0700, "Peter Duniho"
wrote in Message-Id:
:

I've never experienced a stuck valve with this engine, so I don't know what
sort of power loss to expect.

It's not only a specific engine that characterizes the nature of a
stuck valve. The magnitude of the effect of a stuck valve can vary
depending the position in which the valve sticks. If it sticks wide
open, it could contact the piston possibly with catastrophic results.
If it just sticks open a smidgen occasionally, it would obviously be
less severe.


--

Irrational beliefs ultimately lead to irrational acts.
-- Larry Dighera,

Stuck valve or maybe a floating valve?

mike regish

"Kyle Boatright" wrote in message
...

One other thing to consider is a stuck valve. Your description sounds
similar to my understanding of the symptoms of a stuck valve.

KB