Re: Inflight engine shutdowns vs. speedups?

From: (George Hull)
Organization: DirecTell L.C. - Park City, UT. - 1.801.647.0214
Date:         03 Mar 95 02:27:50 
References:   1
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In article <airliners.1995.213@ohare.Chicago.COM>, (Eric
Chevalier) wrote:

> About a week or two ago a United 757 had to abort a landing approach at
> LAX because it's right engine suddenly went to full throttle.  I happened
> to be listening to the tower frequency at the time and the first calls
> from the crewmember handling the radio suggested they had some major
> control problems for a few moments.  (Ultimately the crew got the engine
> shutdown and the flight landed uneventfully.  Although landing with one
> engine on a wet runway must have been interesting.)

The 757 engines produce at least 37,500 pounds of thrust.  An engine at
max thrust will be a real attention getter during an approach where,
presumably, the aircraft is not very heavy.  The twin-engine airliners are
required (as are all airliners) to attain certain performance milestones
with the assumption that the most critical engine will fail at the most
critical time.  That's why the twins are so overpowered on takeoff.  We
call the 757 the "Atari Ferrari" because of its glass cockpit and its
abundant power.

The Pratt & Whitney engines installed on many 757s have what amounts to
"fly-by-wire" engines.  There are no mechanical connections between the
throttles and the fuel controls.  There is a great deal of redundancy in
the electronic engine controls, but nothing's perfect.

> Which leads me to wonder: I know that flight crews (especially at the 
> commercial level) get a good deal of training in unexpected engine-out 
> situations.  But how about the opposite situation, such as this crew 
> experienced?  Do unexpected engine "spin-up" conditions get as much 
> attention during training?

Yes, we do . . during my last simulator session we dealt with a situation
in which one engine "ran away".  It's not a common training situation . .
you can, after all, shut the engine down and revert to the single engine
situation.  And we practice many different engine failure situations, from
the dreaded "V1 cut" to less demanding shutdowns inflight to resolve other
systems malfunctions.

Incidentally, the "real" airplanes seem to handle better with the loss of
an engine than the simulator often does.