Engine failure

I've experienced ice with Continentals on the ground in the lovely warm
months of July and August. Finally learned to pull the carb heat one last
time just as I rolled into position and to get rid of it as I added takeoff
power. It ain't the heat, it's the humidity.

Bob Gardner

"Jose" wrote in message
. ..
I had a situation in the Shenandoah Valley where, during runup when I
checked smooth operation at idle, the engine quit. It started up easily
enough, but quit again at idle. Taxiied back, went to the shop and they
poked around with the plugs and a few other things, finding nothing. Their
theory was that it was carb ice.

Never had carb ice on the ground before.

Several hours later I took off with no problem (during taxi and runup I
applied carb heat periodically).

Plane was a Dakota.

Jose
--
Money: what you need when you run out of brains.
for Email, make the obvious change in the address.

Their theory was that it was carb ice.

Plane was a Dakota.

Interesting. If so, that's the first instance of carb icing I've heard
about with a Dakota.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:

Interesting. If so, that's the first instance of carb icing I've heard
about with a Dakota.

Lycomings rarely suffer from carb icing because the air intake is routed through
the oil sump on most models. This keeps the carb warm.

Unless, of course, you just started the engine a few minutes ago and the oil's
still cold.

As of two years ago, Shenandoah Valley impressed me as having a pretty competent
shop.

George Patterson
Drink is the curse of the land. It makes you quarrel with your neighbor.
It makes you shoot at your landlord. And it makes you miss him.

Here's instance #2 for ya Jay.

A Dakota on our field was owned by a VFR only pilot. Last summer on a trip
from STE to GRB and back, he reported having carb ice 3 times during his
trip. He questioned that it was really carb ice, but said that each time
the engine started to sputter, carb heat smoothed out the roughness in text
book fashion. Each time, the engine then ran smoothly for awhile then got
gradually rougher until carb heat was applied again.

I was at the airport when he returned and reported the problem to the
mechanic. To satisfy the pilot, the mechanic looked over the airplane and
found nothing wrong. It was simply the effect of a very humid day.

Jim

A Dakota on our field was owned by a VFR only pilot. Last summer on a trip
from STE to GRB and back, he reported having carb ice 3 times during his
trip. He questioned that it was really carb ice, but said that each time
the engine started to sputter, carb heat smoothed out the roughness in text
book fashion. Each time, the engine then ran smoothly for awhile then got
gradually rougher until carb heat was applied again.

I was at the airport when he returned and reported the problem to the
mechanic. To satisfy the pilot, the mechanic looked over the airplane and
found nothing wrong. It was simply the effect of a very humid day.

This happened in SUMMER?

Very weird. In our plane, the carb heat is checked prior to take-off,
and never touched again. In fact, I've only activated carb heat once
in flight (in ten years and 1500 hours) in ANY flavored Cherokee -- and
that was just an experiment.

Cessnas are another animal altogether, of course.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Yep, happened last summer. Surface temps were around 70. It totally
freaked this guy out. So bad that it became one of the reasons he sold the
plane. (not a valid reason in my book, but to each his own.)

From a teaching stand point, especially to renter pilots, I've always taught
to use it on landings. Keep the procedures as similar as possible between
airplanes unless there is a good reason to deviate.

I've only needed carb heat once. It was IMC, in the spring, in an Archer.

Jim

"Jay Honeck" wrote in message
oups.com...

This happened in SUMMER?

Very weird. In our plane, the carb heat is checked prior to take-off,
and never touched again. In fact, I've only activated carb heat once
in flight (in ten years and 1500 hours) in ANY flavored Cherokee -- and
that was just an experiment.

Cessnas are another animal altogether, of course.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:

Very weird. In our plane, the carb heat is checked prior to take-off,
and never touched again. In fact, I've only activated carb heat once
in flight (in ten years and 1500 hours) in ANY flavored Cherokee -- and
that was just an experiment.

The only time I've experienced carb ice was in an Archer. Of course I
was at 11,000 ft in cool moist air, but I had never experienced it
before, so I was caught by surprise. I noticed that my IAS was slowly
dropping (like 3-4 kts in the last 15 minutes). The throttle was still
firewalled (which at 11K feet, is ~55%), but I looked at the tach, and
noticed that my RPMs had dropped too. (This was before I was instrument
rated, so I didn't pay as close attention to the gauges as I should
have.) Just as I started to consider panicking, I thought about trying
the carb heat. That resulted in an immediate revolt by the engine as it
swallowed the water from the carb. It actually sounded a lot like an
ice-crusher... After about a minute everything was running smooth again
and I turned off the carb heat. For the rest of the flight I paid
closer attention to tach and had to apply the carb heat several more
times (although less of an event than the first time). Eventually, I
just left the carb heat on for the remainder of the flight.

But I've never had a problem since, so it is not a common event at all.
Sometimes the conditions are just right.


-m
--
## Mark T. Dame
## VP, Product Development
## MFM Software, Inc. (http://www.mfm.com/)
"Madness takes its toll. Please have exact change."

Jose wrote:

I had a situation in the Shenandoah Valley where, during runup when I
checked smooth operation at idle, the engine quit. It started up easily
enough, but quit again at idle. Taxiied back, went to the shop and they
poked around with the plugs and a few other things, finding nothing.
Their theory was that it was carb ice.

Never had carb ice on the ground before.

The carburetor doesn't know whether it is on the ground or in the air. :-)

Matt

Jase Vanover wrote:
I taxied to the maintenance hanger (after being directed there by the FBO
via radio notification of the situation), and explained what happened to the
maintenance guy. He said that there is a stop on the throttle to keep the
idle setting from being too low that probably needed adjustment. Even so,
during shutdown (after restarting), idle setting on the throttle was still
800 - 900 RPM, which should be enough to keep the engine running I would
think.

Did you have the carb heat on when the engine died in the air and off
when you couldn't make the engine fail on the ground? Maybe the idle
setting was low enough that the additional RPM loss due to the carb
heat made a difference.

-R

Sorry so late getting back to the group... away travelling on business.

Carb heat had been on since downwind. I was taught to put carb heat on as
part of my downwind checks every time, when doing manouvers at lower
throttle settings, and approximately every 15 minutes during cruise... which
I'm pretty faithful to. It is also standard part of my runup (both at 1700
RPM and at idle).

This was my third circuit. Carb heat was applied during downwind for all
three of them.

You make a good point that when I did my shutdown after restarting, I didn't
have carb heat on, so the engine not quiting and showing 800-900 could be
because carb heat wasn't on... though it didn't quit on my first two
landings either.


"Rob" wrote in message
oups.com...

Jase Vanover wrote:
I taxied to the maintenance hanger (after being directed there by the FBO
via radio notification of the situation), and explained what happened to
the
maintenance guy. He said that there is a stop on the throttle to keep
the
idle setting from being too low that probably needed adjustment. Even
so,
during shutdown (after restarting), idle setting on the throttle was
still
800 - 900 RPM, which should be enough to keep the engine running I would
think.

Did you have the carb heat on when the engine died in the air and off
when you couldn't make the engine fail on the ground? Maybe the idle
setting was low enough that the additional RPM loss due to the carb
heat made a difference.

-R