"Bob McKellar" wrote in message
...


ANDREW ROBERT BREEN wrote:

In article z,
BackToNormal wrote:
A page at http://en2.wikipedia.org/wiki/Ejector_seat says

"by mid 2003, Martin Baker ejector seats had saved 7000 lives".

Is that figure maybe a little high?

A bit low, according to Martin-Baker's own site:

7023 lives saved to date, 51 this year.

http://www.martin-baker.com/

Delving a bit deeper, the rate of increase was:

1946: First live ejection
1965: 1000 lives saved by M-B seats
1969: 2000 lives saved "
1971: 3000 lives saved "
1976: 4000 lives saved "
1983: 5000 lives saved "
1990: 6000 lives saved "
2003: 7000 lives saved "

figures taken from:
http://www.martin-baker.com/milestones.htm

so it's heavily weighted towards the period 1965-1971, by
which time most fast jets had bang-seats, there was still
a lot of low-level stuff going on with earlier and probably
slightly tricky jets, and the US - using jets equipped
with MB seats - were fighting a war against an opposition
who were capable of shooting back with some degree of
effect - this would all tend to push seat usage up.

Interesting that the highest altitude an MB seat's been
used from (57000') was as long ago as 1958 - and was
somewhat naturally from a Canberra. Wonder if that was
one of the Olympus-engined specials?

Just a question, dealing from my usual ignorance: If you are that
high, wouldn't it ( usually ) be better to wait a while until the
outside air became warmer and more breathable? Several things come
to mind, such as fire or violent gyrations, that might speed up the
decision process, but I'm curious what other more knowledgeable
folks think about the concept..


If, for whatever reason, the crew need to leave the ac at high altitude then
the crew need to be protected as much as possible from the effects of the
low oxygen/cold environment. The seat supplies supplemental oxygen, but
because the pilot needs to get down to thicker/warmer air as rapidly as
possible, the main chute doesn't open right away. Instead, a smaller chute
called a drogue deploys to stabilize the seat so it doesn't tumble and to
slow the pilot's horizontal velocity. In a near free-fall, he plummets
(still in his seat) until he hits an altitude of, typically, 15-10k feet at
which point he separates from his seat and his main parachute automatically
deploys. If I recall correctly, the time taken to freefall from 55k to 15k
is about 2 mins.