Posted on 08/15/2005 8:47:22 AM PDT by devane617
ATHENS, Greece (CNN) -- Investigators were working to determine why a Cypriot plane apparently suffered a catastrophic loss of cabin pressure and slammed into a Greek mountain -- possibly with all 121 people on board already dead. All but two of the bodies have been recovered, a Greek government spokesman said Monday, and officials hope autopsies and cockpit recorders will hold clues to Sunday's crash of Helios Airways Flight 522. The autopsies were ordered to determine if the 115 passengers and six crew were already dead or oxygen-starved before the crash, the spokesman said. A Greek Defense Ministry source with access to the investigation told Reuters that most of the bodies recovered were "frozen solid."
(Excerpt) Read more at cnn.com ...
Bound to happen when they quite providing free blankets and pillows.
The heat exchangers coole the bleed air from the engines. There isn't any CO2 from combustion. The concept is to cool the air by rapid expansion, and removing moisture. this supercooled air is then mixed with the hot bleed air to give you airconditioning.
Another Dover story. Before the C-5's they had 141's and they would do practice drops, equipment & vehicles parachuted out to some place north of here. Periodically they'd mis-drop and on one occasion I remember an old farmer refused to give the AF back the jeep that had landed in his field. His opinion was that it was on his property, so he was gonna keep it. ;)
yeah I remember the 141's... we kept swapping with McGuire AFB (NJ) - We fix them, they returned them broke :)
"The cold isn't what would kill them"
Actualy it was the sudden stop when the plane impacted the ground.
"So its probably an exaggeration of the moment thing."
That might work. It's 60 below at altitude but those poor folks would have had to flown for quite a while exposed to the outside temps to be foezen solid.
The engines generate exhaust, right? From burning jet fuel? Could a busted heat exchanger suck in some exhaust? Is there anything like an exhaust manifold on a jet engine?
It will be interesting to learn the age of the aircraft. Boeing 737's have been in production longer than any other A/C model. They are still in production and are a very good aircraft. Old/high time ones are subject to aging aircrft inspection and repairs. Remember Aloha Airlines, the top blew off in flight. Why would the cockpit crew suffer the effects of what was happening befor the passengers did? There is a pressure bulkhead (F.S 178) just forward of the flight crews feet that must be replaced at a certain time/cycle due to fatigue cracking. If it failed it could account for this loss
compressed air for for the pneumatic system of an aircraft is bled off the engine prior to combustion. The reason you smell jet exhaust while sitting on the ramp is because there are other jet engines running in the area. This exhaust is drawn into the engine of the plane you are on and is introduced into the cabin through the airconditioning system.
I still think this is mechanical error. If not, the odds of cypriot vs. greek terrorism is greater than WOT type terrorists.
And it was a Cypriot airliner, not Greek, so that also reduces the odds of terrorism.
Heated air is taken from the 12th or 13th stage of compression in the engines. it is routed by a sytem of ducting. When it hits a heat exchanger, cold outside are is scooped and forced over a set of coils...like a radiatoe or a set of condenser coils on your AC. It is then diveted to one of two sides. Hot air is routed to anti-ice systems and to the mixing chamber, the other side goes through a turbine/compressor assembly, a water separator and another heat exchanger. it is also mixed with a small bit of outside "fresh" air. the two sides are mixed in the mixing chamber that is controled by thermostats and other controls. There isn't any CO hazard in this proccess. due to the fact of the mixing process actully diludes the air to ground level properties.
/John Maddon Airlines
Great explanation! Very informative for us airplane-challanged.
Helios Airways currently operates a fleet of Boeing B737 aircraft.
Two B737-800 Next Generation 'Veni' and 'Zela', were delivered brand-new from Boeing in May 2001. These state-of-the-art aircraft are furnished with 189 leather seats and an inflight entertainment system.
A third B737-300 series aircraft 'Olympia' was delivered in April 2004, featuring 142 spacious leather seats.
A fourth aircraft has recently been delivered in order to cover our increased fleet requirements, featuring 140 seats.
I think the BBC article I linked to up-thread mentioned that they only had 4 aircraft. Am I correct in assuming from the above that only the 737-300 was an older model?
If memory serves, Dover's museum had one remaining C-141 as of the last time I was there, but that was some years ago.
I gotta admit, while Occam's Razor says this is just a mechanical failure (possibly compounded by pilot error?), when I heard "Cypriot airliner crashes in Greece," terrorism was the first thing I thought of. Greece and Turkey have had a long, long dispute over Cyprus, and there have been a lot of terrorist incidents over the years (including, I think, at least one airliner bombing).
I still think it's a mechanical failure, but for the life of me, I just can't see how a single mechanical failure could cause this. A 737 has two "packs," which are the pressurization and HVAC components, one driven off of each engine. I believe that one pack could supply sufficient pressure to both the cabin and the cockpit, if the other failed. (I don't know all the ins and outs of that...I'm not a pilot, sadly, just an airplane geek.) If the cockpit somehow depressurized, it'd blow the door open to the cabin and depressurize the rest of the plane, that door is not sealed against pressure like the outside doors of the aircraft.
There is a big gauge up on the overhead panel, on the copilot's side, that shows cabin altitude and differential pressure, and alarms go off if the cabin altitude goes over a certain amount. Those alarms go off, the pilots throw on their masks and descend to 10,000 feet or so, no ifs ands or buts. The pressurization systems, and the pilot procedures surrounding them, are designed to prevent something like this from happening.
As for some reports saying the plane was in a right turn when the F-16s found it...that sounds like maybe either it wasn't on autopilot, it got knocked off autopilot, or the #2 engine stalled out (which would yaw the plane to the right). Also, the F-16s reported people in the cockpit, and folks are asking how that could be...maybe the plane was in a descending spiral at that point, and it was at an altitude where people could breathe without assistance. That then begs the question of how somebody survived over an hour (until the F-16s got there) at FL350 with no oxygen, and could even make it to the cockpit.
It may sound morbid, but crash investigation fascinates me. Making order out of chaos, taking acres of twisted wreckage and being able to piece together exactly what happened when...it's the ultimate CSI, the ultimate forensics. And usually, something comes out of the investigation to increase safety.
}:-)4
The 737-300 is an older model, not sure how old, and no longer produced. The -800s are some of the "Next Generation" 737s; they have lots of improvements, "glass cockpits" (where LCD screens or CRTs replace most of the analog instruments), much more sophisticated electronics, better engines, etc. They would be much newer than the -300.
}:-)4
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.