Newsgroups: sci.military.naval
Subject: Re: Inferiority of US Naval Aircraft...
From: Paul F Austin <paustin@digital.net>
Date: Sat, 28 Jun 1997 20:51:15 -0400

Lloyd R. Parker wrote:

> Paul F Austin (paustin@digital.net) wrote:
>
> > A-7, F-8, A-4, F3H... There's nothing holy about having only one hole
> > out the back. The MTBF of modern turbine engines is long enough that
> > it's reasonable to ask "does the second hole pay for itself?"
>
> Gee, up until last year the FAA wouldn't let civilian aircraft fly over
> water with fewer than 3 engines.

Twin engine transports have been operating over water since, oh, the
DC-9. The question is "how long over water?". Operation is permitted as
long as a recovery field is less than IIRC 45 minutes flight on a single
engine. Extended Twin Engine Operations over Water (ETOPS) is the
operation as much as 105 (IIRC) minutes from land.ETOPS have been the
norm for at least ten years, since the A300B was certified. The _new_
thing is ETOPS out-of-the-box. The B-777 was the first transport to be
certified when it entered service.


> Sorry, there are enough AF and Navy crashes on land that you simply
> can't say one engine is as good as 2.  Besides, in combat, what if
> somebody puts a few holes into one of your engines?  If that's your only
> one, it's bail out time.

Data. Most aircraft (the A-10 excluded) have little separation between
engines and not much effort to segregate vital systems to limit the
propagation of battle damage. One of the reasons the 'hog is designed
the way it is was the battle damage history of single and twin engine
fighters over Viet Nam. The loss rate wasn't significantly different. It
turns out that a hit in one engine is very likely to take out other
vital-to-flight systems and the second engine is rarely untouched.

The Navy operated single engine aircraft routinely until the A7 was
retired. STUF drivers didn't suffer inordinately compared to F4.
Certainly the crew feel better with two engines instead of one, they
aren't paying the bill. It's like the recent discussion of CAS
operations. The individual pilot's interest is in maximizing his
immediate survival chances and tends to prefer a point-optimized
solution.

From an operations point of view, if a single engine aircraft allows
about 20% more A/C to be procured, then the overall force may live
longer in _war_. Peacetime operations are another matter. The US tends
to procure A/C with an assumption that most of them will never see a
shooting war, with specifications that maximize cost effectiveness in
peacetime ops. A prime example is the habit of procuring _very_
expensive ordinance that can't possibly be procured in quantities
required by a real war (but that's another rant).


--
Sincerity is the key in politics.
If you learn to fake that, you've got it made.

Paul F Austin
paustin@digital.net