"Mortimer Schnerd, RN" wrote:

Ed Rasimus wrote:
While peace-time redundancy is good--losing an engine due to a
maintenance malfunction, the airplane is still recoverable, the
situation changes in combat. My experience (and admittedly lots of
things have changed since then), was that when the engine loss occurs
due to battle damage, it won't be long before the engine sheds parts,
throws turbine blades, starts a major fire, or whatever. That means
losing the second engine and the situation then is identical to the
single engine airplane.


As for how long the listed aircraft can fly on one engine, I brought
an F-4E with one engine shut-down due to a fire light home from the
NVN/Laos border near Sam Neue, through an aerial refueling and back to
Thailand where I recovered at Udorn. I cleaned the airplane off (the
tanks had already been jettisoned earlier in the mission, and the
racks went when the engine got shut down,) it it flew quite
comfortably.


Ed, these two paragraphs seem to contradict one another. It seems to me if an
engine is shut down before it self destructs catastrophically, you're better off
with the second engine. If it flushes itself too quickly to catch, then you're
no worse off than in a single engine aircraft... flying the proverbial lead
sled.

I don't think there's a contradiction. The first paragraph refers to
losing an engine due to battle damage. If you've take a hit in the
engine, even shutting it down won't stop it from spinning and in an
unbalanced or shattered condition it will still damage fuel tanks,
hydraulic lines, bulkheads, whatever. If it stops spinning (not
windmilling) then you've got a huge speedbrake on that side (note this
is before hi-bypass turbofans) and all bets are off on S/E
performance.

The second paragraph (despite the location) is a classic "peacetime"
engine shutdown. Nothing really wrong with the engine, simply a
precautionary shut-down due to a fire warning light, which in this
instance was a system malfunction, not a fire and not due to battle
damage.

Of course, there are aspects of flight where I'd just as soon just have a single
anyway, but that's been beat to death already.

There are a lot of factors in the equation, with excellent arguments
on both sides. Certainly with improved reliability and increased
performance of jet engines, the idea of fewer is better is taking
hold. While we won't soon see single engine jet-liners, take a look at
the latest generations from Boeing and AirBus--all are two-engine
types rather than three or four. 757, 767, 777 all doing quite nicely
on a pair rather than a handful of thrusters.


Ed Rasimus
Fighter Pilot (ret)
***"When Thunder Rolled:
*** An F-105 Pilot Over N. Vietnam"
*** from Smithsonian Books
ISBN: 1588341038