(D Murphy) (07/05/89)
From: D Murphy <>
BBC News tonight - a Soviet Airforce MiG 23 (Flogger I think) crashed near
Gent in Belgium after flying over West Germany and Holland without its pilot.
NATO radar detected the aircraft and interceptors (USAF) were scrambled when
it failed to turn back at the DDR/FDR border. It apparently took off from
a base in Poland.
Nothing was said about possible causes - the plane seemed to be in working
order until it crashed. Presumably (my opinion) the interceptor pilots noted
that the MiG was unoccupied and did not take any hostile action. The Soviet
plane crashed into a farmhouse, killing an 18 year old man according to the
news report I saw.
Perhaps (again, my opinion - nothing has been said about this) there is a
parallel with a similar incident a few years ago in which a Harrier GR5
on a test flight from British Aerospace was spotted by the crew of a USAF
transport over Southern England with no pilot and the canopy missing -
the Harrier continued in straight, level flight until it crashed into the
Atlantic SW of Ireland after running out of fuel. Faulty ejector seats ?
Murff....
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D.J. Murphy *Artificial* intelligence ? Evidently.....henry@zoo.toronto.edu (Henry Spencer) (07/07/89)
From: henry@zoo.toronto.edu (Henry Spencer) >Perhaps ...there is a >parallel with a similar incident a few years ago in which a Harrier GR5 >on a test flight from British Aerospace was spotted by the crew of a USAF >transport over Southern England with no pilot and the canopy missing - >the Harrier continued in straight, level flight until it crashed into the >Atlantic SW of Ireland after running out of fuel. Faulty ejector seats ? The cause of the Harrier incident is thought to be understood. Actually, what happened was that ground control couldn't raise the Harrier pilot -- a test pilot doing routine chores -- and asked the transport to go take a look. The pilot's body was found; unfortunately the Harrier went down in deep water and could not be recovered for analysis. What happened, clearly, was that the explosive parachute-deployment system fired through the canopy, dragging the pilot out. The question is why -- it is meant to fire only after ejection (to get the parachute deployed in a big hurry in case the Harrier is at low altitude). It turns out that if there is a foreign object of some kind in the right place underneath the seat, at a time when the pilot is adjusting the seat height downward, the actuating rod for the chute-deployment system can get bent enough to fire it. The Harrier's map light -- a little light on a coiled cord -- is the right size to do the trick, and its cord is long enough to reach. There is no way to be sure, but there is circumstantial evidence favoring this explanation. The accident seems to have happened just after the Harrier settled at its cruising altitude. The tests being run were of the oxygen system, and required close attention to the instrument panel. The course was into a low sun, which would have made the panel hard to see. It is not at all unlikely that after putting the bird on autopilot, the pilot would have decided to lower the seat for a better view of the panel. A couple of other explanations were proposed and could not be ruled out, but this seems the likeliest. The map lights were removed until the seats could be modified to fit a guard over the rod. Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu
gahooten@ames.arc.nasa.gov (Greg A. Hooten) (07/08/89)
From: gahooten@ames.arc.nasa.gov (Greg A. Hooten) In article <8028@cbnews.ATT.COM> henry@zoo.toronto.edu (Henry Spencer) writes: >From: henry@zoo.toronto.edu (Henry Spencer) >The cause of the Harrier incident is thought to be understood... was that the explosive parachute-deployment system fired through >the canopy, dragging the pilot out. The question is why...? >Henry Spencer at U of Toronto Zoology My question would be how? This is because I don't understand how the system works, and would love an explanation. Does the explosive parachute-deployment system work to deploy only the chute, or is it hooked to the ejector seat that the pilot sits on? My confusion is, are they two different things, one (the ejector seat) for getting the pilot out of the craft, and two (the para-deploy system) for getting the chute canapy out of the casing before the pilot hits the ground? GAH! Greg A. Hooten
listen@cbnews.ATT.COM (07/10/89)
From: listen >... Does the >explosive parachute-deployment system work to deploy only the >chute, or is it hooked to the ejector seat that the pilot sits >on? My confusion is, are they two different things, one (the >ejector seat) for getting the pilot out of the craft, and two >(the para-deploy system) for getting the chute canapy out of >the casing before the pilot hits the ground? They're two different systems, although they're both part of the ejection seat as currently packaged. A modern ejection seat will fire a cartridge to kick the seat out of the plane, fire rockets to boost it further (in case of an ejection at very low altitude), and then simultaneously cut the pilot loose from the seat and fire the parachute (hooked to the pilot, not to the seat) out of its canister. The best modern seats use a cartridge-plus-rocket system for the parachute deployment too, in fact, to get the chute fully deployed almost instantaneously. The latest production seat, the Martin-Baker NACES system for the US Navy, can get the pilot on the ground safely after an ejection from an aircraft flying at 100 feet UPSIDE DOWN. There are experimental "vertical-seeking" seats that know which way is up and can vector rocket thrust to turn around in mid-air and head upward, but the NACES seat is not one of them -- it just gets the parachute out awfully fast at low altitude. It does measure altitude and speed as it leaves the plane (using its own sensors), so it can decide whether panic-mode chute deployment is in order. Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu
(D Murphy) (07/11/89)
From: D Murphy <> In article <8093@cbnews.ATT.COM> listen@cbnews.ATT.COM writes: > >They're two different systems, although they're both part of the ejection >seat as currently packaged. A modern ejection seat will fire a cartridge >to kick the seat out of the plane, fire rockets to boost it further (in >case of an ejection at very low altitude), and then simultaneously cut >the pilot loose from the seat and fire the parachute (hooked to the pilot, >not to the seat) out of its canister. The best modern seats use >a cartridge-plus-rocket system for the parachute deployment too, in >fact, to get the chute fully deployed almost instantaneously. The latest >production seat, the Martin-Baker NACES system for the US Navy, can get >the pilot on the ground safely after an ejection from an aircraft flying >at 100 feet UPSIDE DOWN. There are experimental "vertical-seeking" seats >that know which way is up and can vector rocket thrust to turn around in >mid-air and head upward, but the NACES seat is not one of them -- it just >gets the parachute out awfully fast at low altitude. It does measure >altitude and speed as it leaves the plane (using its own sensors), so it >can decide whether panic-mode chute deployment is in order. > > Henry Spencer at U of Toronto Zoology > uunet!attcan!utzoo!henry henry@zoo.toronto.edu The Soviets have these too. TV film of the MiG-29 (Fulcrum) crash at the Paris Airshow '89 showed that the plane was heading vertically for the ground when the pilot ejected at what must have been 50 - 100'. Upon leaving the plane the seat righted itself and deployed the chute immediately. It hadn't opened fully before hitting the ground but must have provided some breaking as the pilot bounced once but virtually walked away from the crash (leaving a big expensive and embarrassing hole behind him). Presumably a higher altitude ejection would have resulted in the seat moving further from the plane before deploying the chute. Paris doesn't seem too lucky a place for the Soviets :-) [mod.note: Fair is fair. Moscow wasn't all that lucky for Napoleon 8-) - Bill ] Murff.... JANET: djm@uk.ac.ed.etive Internet: djm%ed.etive@nsfnet-relay.ac.uk Murff@uk.ac.ed.emas-a Murff%ed.emas-a@nsfnet-relay.ac.uk trinity@uk.ac.ed.cs.tardis trinity%ed.cs.tardis@nsfnet-relay.ac.uk D.J. Murphy *Artificial* intelligence ? Evidently.....