My engine quit!

I had a similar scenario with IO-470s that would quit at idle on the roll
out. Windmilling on short final kept them running. Turned out the fuel
pressure was too high from the engine driven fuel pump at idle, and the idle
mixture was too retch. (boost pump off)

It might have quit in the same way yours did, but standard technique is to
keep a few inches of power on until just over the threshold (otherwise sink
rate was too high) , so there were no opportunities to quit.

It does get your attention.

Paul Tomblin wrote:
snip

So I figure I probably flooded it.

snip\

can you flood an engine while it is running? I'm not an engine guy, but
with the throttle at minimum, not much fuel should be going in, and this
is not much different from taxiing, except you would usually lean for
that. Might be running richer than you like, but that happens during a
normal landing since you are running at low rpm's, throttle low, mixture
rich, fuel pump on, pretty much what you were doing, except in your case
the throttle was lower for longer. You might expect some fouling if you
ran like this for a while, but I don't see how it can flood as long as
the spark plugs are doing that sparky thing they do.

Of course, I could be all wet here.

Brad

In a previous article, "Private" said:
(and during) and clear the engine frequntly during any extended closed
throttle operation such as engine out practice and testing. IIRC the

I always thought "clearing the engine" was an old instructors tale, like
shock cooling.

What does the POH say about closed throttle decents?

Nothing. All I can find is that for normal approach you use mixture on
full and electric fuel pump on.


Is there a proceedure for rapid decent such as a passenger health prolem?

Nope. I was taught to do a steep turn for that.

ISTM that mixture is altitude dedendant but I do not know yours. Many seem
to benifit (reduced lead fouling of spark plugs) from aggresive leaning when
operating at closed or partial throttle.

We definitely find a benefit to agressive leaning on the ground.

If this is a club plane regularly used for training then I suspect that this
has happened before and the club should have developed an approved
proceedure to deal with the problem.

It's not generally used for training, but our club requires that you do
your BFR every year, and do it in the highest category plane you intend to
fly that year, so I have to do it in the Lance or I'll be stuck flying
PA28s all year.

I would be concerned about operational failure should increased power be
required for go-round or if coming up short.

Yeah, me too. That's why I'm researching this issue. Today or tomorrow I
plan to start the plane on the ground and see if the engine floods and
dies with the throttle at idle and the mixture full rich and the electric
pump on.

--
Paul Tomblin http://blog.xcski.com/
"Panic kills"
-- Rick Grant (quoting RCAF pilot training)

In a previous article, The Visitor said:
You call it a boost pump, this is a turbocharged engine?
Was it on high or low?

It's officially just called the "electric fuel pump", as opposed to the
engine driven fuel pump, but we call it "boost pump" for short.


--
Paul Tomblin http://blog.xcski.com/
When C++ is your hammer, everything looks like a thumb.
-- Steven M. Haflich

(Paul Tomblin) wrote:
ISTM that mixture is altitude dedendant but I do not know yours. Many seem
to benifit (reduced lead fouling of spark plugs) from aggresive leaning when
operating at closed or partial throttle.

We definitely find a benefit to agressive leaning on the ground.

My club has a 180 HP Arrow which has always been prone to plug fouling
during taxi (even across a couple of engine changes through the years). I
was taught to use "aggressive leaning" on the ground to solve that. I have
faithfully done so, and taught numerous students to do the same. I have
found that it really does cut down on plug fouling, or at least I've
convinced myself that's true.

Then, we recently put one of those electronic fuel computer thingies in the
plane. Great gadget -- it tells you your fuel flow to the 10/th of a
gallon per hour. Accurate as hell. Really tells you what's going on to a
degree that was impossible with the old analog gauges.

The only problem is, the damn thing says the fuel flow doesn't change one
iota between full rich and "aggressively leaned" with the engine running at
1000 RPM on the ground :-)

"Paul Tomblin" wrote in message
...

I always thought "clearing the engine" was an old instructors tale, like
shock cooling.


I have always been taught to clear the engine occasional during throttle off
operations. But I learned to fly 30 years ago. Have most CFIs stopped
teaching it?

And what about "shock cooling"? I flew a jump plane years ago, and the owner
always limited decent speeds and forbided complete throttle off operation. I
can't remember for sure, but I think he insisted a max of 85 mph and 12" or
so.

In a previous article, "Maxwell" said:
And what about "shock cooling"? I flew a jump plane years ago, and the owner
always limited decent speeds and forbided complete throttle off operation. I
can't remember for sure, but I think he insisted a max of 85 mph and 12" or
so.

I've talked to sail plane tow pilots, and they climb at max power for
several minutes, and then close the throttle and dive for the ground at
Vne. If shock cooling was a real problem, they'd be losing a jug every
day.


--
Paul Tomblin http://blog.xcski.com/
"Grove giveth and Gates taketh away."
- Bob Metcalfe (inventor of Ethernet) on the trend of hardware speedups
not being able to keep up with software demands

"Paul Tomblin" wrote in message
...
In a previous article, "Maxwell" said:
And what about "shock cooling"? I flew a jump plane years ago, and the
owner
always limited decent speeds and forbided complete throttle off operation.
I
can't remember for sure, but I think he insisted a max of 85 mph and 12"
or
so.

I've talked to sail plane tow pilots, and they climb at max power for
several minutes, and then close the throttle and dive for the ground at
Vne. If shock cooling was a real problem, they'd be losing a jug every
day.



I don't doubt it Paul. I always wondered how valid it was, expecially since
we were using a 182 with cowl flaps. But it sure delayed our decents.

bsalai wrote:
Paul Tomblin wrote:
snip

So I figure I probably flooded it.

snip\

can you flood an engine while it is running? I'm not an engine guy, but
with the throttle at minimum, not much fuel should be going in, and this
is not much different from taxiing, except you would usually lean for
that. Might be running richer than you like, but that happens during a
normal landing since you are running at low rpm's, throttle low, mixture
rich, fuel pump on, pretty much what you were doing, except in your case
the throttle was lower for longer. You might expect some fouling if you
ran like this for a while, but I don't see how it can flood as long as
the spark plugs are doing that sparky thing they do.

Of course, I could be all wet here.

Brad


I've managed to do this once at a high altitude airport. We've flown
into Big Bear (L35 eleveation 6752) many times in the Turbo Lance II. On
one particular landing the engine coughed and died as we rolled off the
runway. Mixture was just a bit richer than it should have been. Never
had it do that at lower elevations. Hot starts are always a pain, worse
so at elevation it seems -- but I did get it running again.

Paul, what is the field elevation where you are flying?

Steve
PA-32RT-300T

Paul Tomblin wrote:
In a previous article, "Private" said:
(and during) and clear the engine frequntly during any extended closed
throttle operation such as engine out practice and testing. IIRC the

I always thought "clearing the engine" was an old instructors tale, like
shock cooling.


Nope. The most likely time to foul plugs is when an engine is at idle or
very low power settings, which is why leaning during taxi is so popular. The
combustion process gets very dirty at low power settings. The fixed timing
is optimized for high rpms, so it's not optimal with the throttle back. Also,
combustion temperatures drop to the point where lead in the fuel is not
completely vaporised, which leads to deposits.

John Galban=====N4BQ (PA28-180)

--
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