My engine quit!

"Paul Tomblin" wrote in message
...
I was doing my BFR last night in my club's Piper Lance (in case you're not
familiar: it has retractable gear and a IO-540 fuel injected engine). We
finished up with a bunch of touch and goes, demonstrating short, soft,
etc. The last landing, the instructor pulled the throttle and had me do a
forced landing. I had no trouble making the runway, and rolled off the
runway and over the hold short line. As I was tuning the ground frequency
on the radio, the engine died. And I was unable to restart it and neither
was the instructor - I ended up having to call the FBO to tow me back to
the tie down line.

It wasn't until some hours later that it hit me - during the forced
approach, I had the throttle at idle, the mixture at rich and the boost
pump on. Which is exactly how you prime it for a cold start - except for
starting you only do it for about 3 seconds, and this was for the whole
duration of the forced approach. So I figure I probably flooded it. So
what's the answer? Do you turn off the boost pump when doing practice
forced approaches? What about normal approaches? Does that mean turning
on the boost pump has to become a normal action on go-arounds and touch
and goes?

--
Paul Tomblin http://blog.xcski.com/

Did you perform the (required?) engine clearing procedures during the
decent?

What does the POH say about closed throttle decents?

Happy landings,

In a previous article, "Private" said:
Did you perform the (required?) engine clearing procedures during the
decent?

No.

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.

--
Paul Tomblin http://blog.xcski.com/
Computers are not intelligent. They only think they are.

"Paul Tomblin" wrote in message
...
In a previous article, "Private" said:
Did you perform the (required?) engine clearing procedures during the
decent?

No.


My training schools required SOP was to use carb heat (if avail.) before
(and during) and clear the engine frequntly during any extended closed
throttle operation such as engine out practice and testing. IIRC the
frequency was every 300-500ft. IIRC there is a TC requirement for clearing
during flight testing and that proper clearing is part of the task grading
as per the published Flight Test Standards. There is also a restriction on
'over-clearing' when coming up short. IIRC some examiners say that they
will perform or instruct when to clear.

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?

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.

Could there be a problem with any fuel or pressure regulaing valves?

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.

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

Happy landings,

--
Paul Tomblin http://blog.xcski.com/
Computers are not intelligent. They only think they are.

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)

(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 :-)

Roy,

The only problem is, the damn thing says the fuel flow doesn't change one
iota between full rich and "aggressively leaned"


Ours does. Same engine. Guess your "aggressive" isn't aggressive enough.

--
Thomas Borchert (EDDH)

"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.

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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