On Jul 15, 12:09 pm, wrote:
We are told, Vaughn, that engine failures sometimes happen when power
is first reduced after take off. I don't know what the statistics are,
but think failures in the downwind/base/final portions of flight are
not very common.

Failures at power reduction are no more common than any other
sort, except perhaps in ultralights with their two-strokes that tend
to seize up if they're not fully warmed up before takeoff, and they'll
sometimes stop when power is reduced but they were going to quit soon
anyway.
Failures can happen anywhere. I've had an engine fail in the
glide and another busted its crankshaft on climbout. Most common
failures, by a wide margin, are attributed to carb ice, and it will
get you anywhere at all if you're not educated enough to be aware of
(A) what causes it, (B) when the risk is highest, (C) and what is
sounds like. Every so often I hear of another airplane that had its
engine quit, the conditions were perfect for carb ice, and the engine
ran fine for the accident investigators. Carb ice could cause engine
failure on power reduction, as the ice will be closing off the carb
throat and the closing throttle valve will finish it. Maybe that's
where the OWT comes from?
Next most common cause is fuel starvation, more commonly called
running out of gas or, sometimes, mismanaging tanks. Water in the fuel
is third, then practice forced landings (when the thing iced up or got
cold enough it didn't wake up for the overshoot), and the fifth is oil
starvation. Not very common, that one. Catastrophic mechanical failure
is rare (like the broken crank) and is usually found in airplanes that
are poorly maintained or maybe abused.

Dan