"Longworth" wrote

Last month, we learned a great way to fly from an
instructor who specialized in Cardinal flying. One of the maneuvers
we learned was the spiral emergency descent. I could not believe how
we could do steep spiral 2000' over the number, dropped like a 'coke
machine', executed a super slip, kicked it out the last few seconds
and landed as soft as a butterfly right over the number.

Sounds like it would be more fun than the best roller coaster ride!

I had only
done it once on my own after the training but plan to do it more
often. I don't believe in shock cooling and seriously doubt that such
maneuver can harm my engine. Even if it does shorten the life of my
engine, I will continue to practice it until I can execute it
flawlessly all the time. I may never need to use the skill for real
but knowing that I am ready to do it in any situation boosts my
confidence tremendously. Besides, it is sheer exhilaration practicing
the maneuver. Definitely worth the price of the engine overhaul ;-)

It sounds like you do have your priorities in line, with the right
compromises of possible engine life sacrifice (a matter not clearly
established) and skills maintenance.

Doing a chop and drop when your engine isn't as hot as a firecracker should
not be harmful, in the least bit. Considerations of the towplane engine
long life is a good example, and one that is hard to argue with. They are
no doubt pretty hot when they start their rapid descent to pick up another
tow.

If one were to start the rapid drop (engine failure simulations) after
letting the engine cool a bit (by reducing power settings, or richening the
mixture, or both) and stabilize for a few minutes, the amount of additional
cooling from that power level, even in a worst case scenario, should not
cause a measurable increase in wear. It is mainly the hot piston cooling
more slowly than the cylinder bore, cutting down on the clearances, that can
increase wear. The stabilizing should eliminate that problem, all together.

The concern of hitting the throttle for a go around may be a concern,
although it is hard to see why that is any harder on the engine as the
takeoff full power applications. If that go around full power is what
concerns you, (or Jay) don't do a go around, except for the occasional
practice, (or real go-around) then just do the full stop, taxi back and
takeoff after everything is nicely cooled down.

I agree with the people that are saying that the practice of emergency
engine failures would have to be a good thing to practice. Doing it
carefully as to not damage your engine would seem to be prudent. Not doing
them may be not prudent.
--
Jim in NC