Helios 733 crash north of Athens

[KevinAu 441]

The packs on commercial airliners are air cycle machines. There is no refrigerant or chemicals used.

[Guest Shalomar]

Donny AKA ShalomarFly 2 ROCKS!!!Different plane, but a 777 on a demo flight decompressed due to a problem with the couplings on the A/C system. Some kind of adapter issue, the NG being a reworking could it use similar couplings? The masks in the cabin do drop automatically, but it is part of the procedure to deploy them manually and ensure O2 flow just in case the auto system didn't. When I was 9 years old, my father's Rockwell 690 B suffered pressurization problems. The first thing I remembered was when my stepmother woke me up by shoving a bottle to my face. Why she chose me rather than my older brothers or sisters who actually had some stick time I don't know. Everyone was asleep I thought till I looked at the cockpit and saw my father slumped backwards over his seat. He was wearing a canola, but it wasn't helping him, cabin pressure must have been above 18,000. I always kept my seat belt on as per dad's instructions. I didn't want to disobey even in this situation plus I wasn't on O2 long enough to think of getting up to the cockpit to use the radio. I grabbed the airphone next to me and dialed 911. Having read Airport, I told the dispatcher "Im in an airplane, I'm in an airplane. I'm in an airplane!""Why'd you say that three times?""This is no time to talk slow. No time to talk slow. No time-""Yeah, youre in an airplane.""Ya gotta call the tower, call the tower, call the tower.""Why?""We have pressure problems, we have to leave our altitude, ya gotta tell the tower!!!""Okay, I have to tell the tower.""Gail, I want you to look between your seat. Find the swich that reads "ALT hold" but don't touch it yet. Pull the trottles back to idle. When you hear a horn then click that switch."She gave me an alarmed look."Gail, don't worry, it's a jet!""Which one's the throtle?""The big ones.""Who are you talking to?" says the dispatcher."My stepmother. I thought she was worried about shock-cooling the engines, but it doesn't matter.""You're in a jet?" "NO, a turboprop, jets driving propellers.""Why were you so quick to correct yourself?""Cuz if I pile on too many contradictions you'll think it's a crank call and hang up on me.""OH s----, J---- kid, I'm sorry I did think that...""You didn't call the tower??? Listen, in a few seconds I'm gonna start sounding delerious.""Why?""CUZ NOW I HAVE TO PASS THIS BOTTLE AROUND!!!""NO kid, don't do that, I'm helping you RIGHT NOW.""Just call the tower, and (I heard a click) say "Sixteen Echo, problems, pressurization, gotta get down fast!!!"A different voice."16 Echo, cleared for imediate descent to 10,000."Throttles at idle, altitude off at the stall horn was sufficent in this case. Our wings stayed reasonably level, near 10,000 throttles advanced and the altitude hold on. A few dipsey doodles and it was over. Dad recovered quickly, the canola started helping once we got below 18,000 feet. Dad thumped it on at Queen City Municipal in Pennsylvania, where he had taken his initial lessons. Our original destination had been KPHL from Montreal. Must have been a gradual failure, we never should have been able to get everybody back after as long as it seemed to take to start down from altitude. Shoulda used the radio, but I was nine, and recovering from O2 deprivation.May God have mercy on the not so lucky ones in Greece.Best Regards, Donny:-wave

[Guest 737typerated]

WigBaM,Here's a description of the 737 air condition system http://www.b737.org.uk/airconditioning.htm no R22 dude, just lots of CCCCold ram air getting heated and cooled by the air cycle machine.The air cycle machine also presurizes the airplane cockpit/flightdeck and the cabin.When the crew made the call to ATC about the air condition system problem, they were having an aircraft pressurization problem, they did not give a hoot about the temperature, they were having a problem keeping the plane pressurized.

[KevinAu 441]

>>When the crew made the call to ATC about the air condition>system problem, they were having an aircraft pressurization>problem, they did not give a hoot about the temperature, they>were having a problem keeping the plane pressurized. I doubt that plane ever even pressurised (or compressed, as people like to call it for some reason). The call to ATC about the pressurisation problem came shortly after takeoff according to the media. Probably well before the plane got to 34000. The more news reports come out, the more normal this accident sounds. Most likely the autopressurisation failed from the getgo, the crew decided to continue on up since this was something that has happened before and like before, were expecting to reset it and have it work as normal after resetting. As the cabin altitude climbed with the aircraft during their attempts to troubleshoot the pressurisation, they put their masks on, unfortunately, for whatever reason, the cockpit O2 bottle failed to provide the masks properly with air. Hypoxia sets in and they finally, slowly, and lethargically, realize that they were not getting oxygen. Captain gets up out of his seat to check the bottle, but collapses. FO also has collapsed. Plane continues up to altitude by itself, levels off, flies the flightplan route, enters a hold near Athens, and finally crashes there. After 12 minutes or so, passengers also run out of O2. Depressurisation (or decompression, as people like to call it for some reason) at 34000 was never a factor here. Everybody was probably lights out by the mid-20s.Or it could have just been one of the pilot's suicide plan. Or maybe Aliens had captured the plane, stopped time, abducted everybody and replaced them with lookalikes before setting the plane free. Who knows.

[Guest FS_freak]

...Everybody was probably lights out by the mid-20s.It's an excellent proposition. You could've stopped there. No need for the Alien or suicide BS.Mauricio

[KevinAu 441]

>>It's an excellent proposition. You could've stopped there. No>need for the Alien or suicide BS.>>>MauricioThat's just to make btacon happy.

[Guest advocatexxx]

unfortunately this would go against some facts. the F-16 pilots which intercepted the airplane did so after it's been cruising for some time, and when they did it's been leveled at FL340 for some time, yet they still observed some people struggling to regain control of the plane. even the emergency oxygen supply lasts for mere 15 minutes, so how did these people manage to survive, and why haven't they been able to disengage the autopilot (if, as i understand it, a good enough push on the yoke would've done the trick)?

[KevinAu 441]

Placed throughout the cabin, there are several 1800psi portable oxygen bottles. These are for the use of FAs who have to walk up and down the aisle if the aircraft is depressurised and for emergency medical use. There would be enough O2 in these bottles for several people for at least 30-70 minutes.Whether or not these people ever played PMDG's or DF's 737 and have any working knowledge of how to regain control of the airplane I do not know. My bet is no. The force required to disengage the AP purely by pushing/pulling on the yoke is very heavy and if you did not know that it was possible, you probably would not be using enough force to do it. There are easier ways to disengage it such as the AP switch, the AP disconnect, and the trim switches. Again, apparently none of these people were airplane buffs and probably had no clue.

[btacon 1,795]

Hey Kevin...You're a fool!Cheers,bt

[KevinAu 441]

:( ...

[btacon 1,795]

Wow Kevin...not only are you a fool, but you are a hypocrite. I quote you from this thread:"All in all, this story smells of fish. Either extreme malice or extreme incompetence is required to take a so called air-conditioning problem to this outcome."In my mind, you and I have said nothing different, only for some reason, you feel I cannot say what I want to say. Doesn't matter. What is, is.For some reason, you feel compeled to control what I say. That's sad, and I guess I feel sorry for you.Cheers,btKevinAu Mon Aug-15-05 07:45 AM Member since Mar 07th 2002 635 posts #21140, "RE: Helios 733 crash north of Athens" The masks in the cockpit are quick donning masks, not the kind that deploy from the ceiling like those in the cabin, and are always within reach. If the cabin altitude exceeds 10,000' there are warnings in the cockpit.Even if both packs failed suddenly, it would still have taken several minutes for the cabin altitude to reach 33,0000' as the pressurisation outflow valves will go into the fully closed position, limiting the rate at which the aircraft depressurises. It is not an explosive event like movies will make you believe. Only if there was a big hole in the cabin would the cabin immediately vent to an altitude of 33,000'.All in all, this story smells of fish. Either extreme malice or extreme incompetence is required to take a so called air-conditioning problem to this outcome.

[KevinAu 441]

Wow Braun, you really need to get a grip. The Aliens and reference to you were nothing more than a friendly jab at you and your constant conspiracy theories. Nothing more. Nowhere in any of my replies was I replying to anything you wrote until you called me a fool. I haven't agreed or disagreed with you in any of my postings about packs, or O2 bottles or pressurisation failures. In fact, none of my more serious postings actually had you in mind until the one jokeline about the suicide and alien theories. Take a look at the thread in threaded mode. Like I said, _the more information comes out_ the more this accident seems like a regular chain of events and decisions that unfortunately led to a smoking hole. Therefore, my later postings went against the first one which said the accident was fishy. And I reserve the right to change my mind as new information comes out. Braun, I wasn't trying to control what you say, in fact you weren't even in my picture.

[btacon 1,795]

Well...ok Kevin. So say you.Now we understand each other.Best,bt

[btacon 1,795]

At the end of the day Kevin, I would suspect your theories are pretty close. Still there remains some stinking facts:* System monitors did not appear to alert crew* Absence of PIC (back of plane perhaps, trying for O2)* Folks seen in cockpitThe whole thing seems like an episode of the Twilight Zone.At the end of the day, I go back to my title for this sub-thread:"Can't explain the unexplainable."Cheers,bt

[geoffco 0]

>...Again, apparently none of>these people were airplane buffs and probably had no clue.If I was in that situation I'd go for the radio rather than trying to control the aircraft... and I think anyone who could get into the cockpit would be able to communicate with ATC in some way, regardless of their knowledge of aviation. I was under the impression that the passengers that were seen moving around by the F-16 pilots never got into the cockpit. Instead, they were seen trying to open the cockpit door - which would probably have been locked.That's what I heard (BBC Radio4 News - UK) anywayGC