Re: 2 vs 4 engines: R&D costs too much ?

Date:         21 Nov 99 23:56:51 
From:         "Jerry" <>
Organization: AMD
References:   1 2 3 4
Followups:    1 2 3
Next article
View raw article
  or MIME structure

Your points are all excellent and I'm glad you also added the
reference to Burt Rutan's ARES.

If economics was the *only* reason to choose a particular design,
I think your ideas are very good.

The problem is that both Boeing and the airlines also ask
other questions such as "do the passengers like it and
what will the passengers think".

We live in a symmetrically perceived world, even if it is
at times asymmetrical.

That said, while I would love to fly in *any* novelly designed
aircraft, a lot of passengers might balk and say "where's the
fourth engine - somebody forgot to put the last engine on
the left wing". Infantile and idiotic, yes. But those infantile
and idiotic assertions come from passengers with money to
purchase tickets.


I am really sorry to see both the L-1011 and the DC-10/MD-11
go. I don't recall *any* incident of a double engine out
scenario on either a DC-10 or an MD-11.

But it *has* happened twice on the L-1011, both Eastern Airlines
aircraft; fortunately for the comfort of the pilots, the
last remaining engine was #2 (tail) so no asymmetrical thrust
issues to deal with on landing.

One was flying from the Caribbean and lost all three engines
(due to some maintenance procedural error with engine oil,
I think). By some miracle, they were able to restart #2
and landed safely in Miami.

The other was back in the 1970's when an EA L-1011 on a
maintenance ferry flight (to repair an inop #1 engine) from
Mexico City to Miami was cleared to take off with only
#2 and #3 engines working. [Apparently, without pax and
with no cargo and light fuel load, the "book" says you can

Engine #3 catches fire 10 minutes after departure and the
aircraft makes a (very hard) emergency landing back in
Mexico City (and proceeds to break several tires on

My point is that, I like the idea of that third engine ---
losing one engine on a twin means you cannot lose
one more. And I am a huge fan of the 777 but this
is my only caveat with this magnificent aircraft.

My $0.02,