Cypriot \"HELIOS\" airliner crash in Greece

[EHM-1366 Themis]

A B737 of "HELIOS" airlines crashed at Grammatiko, near Tanagra AB (LGTG).
For the last 45 mins (20 mins after t/o) they had lost contact with either Leycosia or Athens Control.
Two F16s intercepted and escorted the "ghost" airliner. The pilots reported that they saw the captain lying on the panel and no co-pilot onboard. They also reported some oxygen masks hanging inside. However no signs of decompression, there were no frozen windows nor any structural damage!

The 737 had destination Prague with a stop at El. Venizelos. After reaching over LGAV the plane started making circles until it burned all fuel and crashed.

A passenger of the flight had managed before the plane crashes to send an sms to a relative telling that the pilots had gone blue and the passengers are freezing!

[EHM-1366 Themis]

Despite to what the media are saying here, it is my opinion that there mustn't have been any decompression or air-condition failure. These are situations where the pilots have time to react and even report the situation.

Whatever happened upthere should have happened rapidly, before the pilots became aware of it. The blue color of the pilots shows that they could not breathe adequately, a possible lack of oxygen in the captain's cabin!?!?!

[EHM-0005 Maarten]

From a F16 it is practically impossible to detect a decompression of an aircraft flying near by.

At this moment, everything points towards a (rapid) decompressions. The incapication of both pilots could be the result of 2 possible situations:

1. They didn't don their mask fast enough and exceeded the Time of Useful Concisiousnes (TUC). At an altitude of 30000 ft the TUC is approx. 30 seconds for a healthy person.

2. A malfunction in the oxygen system. The 737 has two oxygen systems. One for the crew and one for the passengers. The first signs show that the passengers did have oxygen (because a passenger sent a text message), but the pilots not (co-pilot lumping over the flight controls). At an altitude of more than 10000 ft, the health of passengers could be affected because the pax oxygen system is not under pressure.


At this moment, I have no idea how high the aircraft flew. At the moment that a text message was sent, the aircraft could not be on an altitude of more than 6000 ft (approx. max. range of GSM poles).

[EHM-0005 Maarten]

Decompression
A decompression will result in hypoxia. One sign of hypoxia is that the finger nails turn blue. A change in color of the skin is also visible after some time (eventually blue). Finally, hypoxia results in unconsciousness and death.

If the pilots didn't react quickly enough and the symptoms already started then they are not capable enough anymore to detect their own decrease in performance. This is called "euphoria" and it gives the pilot the feeling that he is capable enough to handle the situation.

[EHM-1366 Themis]

From a F16 it is practically impossible to detect a decompression of an aircraft flying near by.

I'm wondering that if there was a decompression, then the windows should had frozen. Instead they were clear enough for the fighter pilots to see through...

1. They didn't don their mask fast enough and exceeded the Time of Useful Concisiousnes (TUC). At an altitude of 30000 ft the TUC is approx. 30 seconds for a healthy person.

What can make these pilots not to wear their maks then? 30 seconds are enough time for a trained pilot to start a descend and wear the mask. Because they were certainly informed about a possible malfunction from the annunciator panel...
Why they didn't even put 7500 7600??? No communication at all!

At this moment, I have no idea how high the aircraft flew. At the moment that a text message was sent, the aircraft could not be on an altitude of more than 6000 ft (approx. max. range of GSM poles).

Correct. In addition until then, there is no mention about panic, anyone faint out or anything else, apart from the freezing temperature. The passengers shouldn't be aware of the situation until that time.

I'm really sceptical about the causes of this accident. Some things don't fit together.

The most instinctive response to a decompression situation is to push the sticks forward and begin descend. But it seems that the pilots didn't have time to respond at all.

[EHM-0005 Maarten]

I'm wondering that if there was a decompression, then the windows should had frozen. Instead they were clear enough for the fighter pilots to see through...

I find it hard to say something about this. It all depends on the duration of the decompression at the time that the fighters arrived. The systems of an aircraft make the air more humid so that could have caused ice formation on the cabin windows. However, if this systems failed as well (it is part of the pressuration/airco system) then the humidity would be between 5 and 15%, so then you don't have ice formation on the cabin windows.

What can make these pilots not to wear their maks then? 30 seconds are enough time for a trained pilot to start a descend and wear the mask. Because they were certainly informed about a possible malfunction from the annunciator panel...
Why they didn't even put 7500 7600??? No communication at all!

Note that an emergency is an extreme stressful situation that can cause people to do things they shouldn't have done (or they omit to do something mandatory). It happened many times in the past that pilots did not don their mask at first, because they are still identifying the problem. In flight training, you'll notice that every instructor states that the first thing you have to do is to don your mask.

Saying something about the communications is very hard too. This accident will be evaluated in detail and a timeline of occurences will be made to get a better view on the situation. If the pilots had their masks on, they could communicate with ATC. Every quickdonning mask on the flightdeck is equiped with a radio headset.

I hope they didn't want to squawk 7500, because that would mean a hijack.

I have multiple situations in my head that could have happened, but a hijack situation is, in my opinion, not the case.

[EHM-0005 Maarten]

The passenger that sent an SMS is mysterious for me too.

The sender of the SMS said that the pilot turned blue. So then why was this pilot not on the flightdeck? It could confirm the observation of the F16s. The fighterpilots reported that they had seen the co-pilot lying unconsiousness over the controls, but they didn't see the commander of the aircraft. At that moment, the aircraft could not have been at a high altitude, because the range of the GSM poles is limited (as stated before).

So let's say the pilots both turned blue then I can only think of 2 situations:

- Hypoxia (due to decompression)
- Poisonning (maybe due to bad oxygen or in the worst case: food)

In both cases, the pilots are incapable of doing anything. This brings me to my next point of questioning.

If the flight crew were incapable (turning blue due to hypoxia; poisonning) then why weren't the passengers incapable too? That guy was still able to send a SMS to his cousin!

A theory to this question could be:
The aircraft suffered a decompression and started its descent. Oxygen was supplied to both passengers and pilots (as I said, pilots have their own oxygen system). Then the problem could be in the oxygen system of the pilots: malfunction, corrosion inside the tank causing the oxygen to become toxic). There are no checks to observe the conditions of the oxygen tanks inside.

--------------------------------------------------
Poisonning would mean that someone did something with the food on purpose, because commander and co-pilot have different meals to avoid poisonning of the whole flight crew.

[EHM-1507 Manuel]

Somthing i absolutely don´t understand is the case:
That passenger must have been to the cockpit (cause he saw the skin colour of the pilots), must have gone back to his seat and sit down, turn on his mobile phone and write an SMS??
It´s hard for me to understand, that someone would do something like this in fear of his life.....

[EHM-0005 Maarten]

That's probably not the case.

Most likely the commander of the aircraft was not in the cockpit (the fighterpilots observed that), but in the cabin (observed by the passenger who was sitting in his seat).

[EHM-1366 Themis]

So let's say the pilots both turned blue then I can only think of 2 situations:
- Hypoxia (due to decompression)
- Poisonning (maybe due to bad oxygen or in the worst case: food)

That is exactly where I was heading to Maarten, poisonning of oxygen, or food.... It's the only situation where the pilots do not have time to react, otherwise some short of reaction whould had occured, even just push the controls forward to descend!
I stick on the issue that the passengers were just cold, not poisoned (as it occurs by now). At some time it seems that the captain opened the door and went to the passengers cabin, and then the poisoned air could bleed to the passengers too. But we don't have any clues that passengers were in any form poisoned.
That leaves to me only one option, that of food poisoning.

Also the plane doesn't seem to have crashed due to run out of fuel. The smoke from the fire at the crash site was black, which reveals the presence of fuel I suppose. But it may have not crashed itself either; The F16 pilots reported that at sometime they saw two people in the cockpit, presumably trying to take control of the plane. If this is the case, then we forget the air poisoning and we stay with the second assumption, that of food poisoning of the commander, co-pilot. ?  ?  ?  ?  ?
Could the two clockwise circles over LGAV be executed by autopilot or someone else tried to take control and land the airplane?
I'm realy astonished by the facts, it is one of the most weird accidents in the recent years

[EHM-1507 Manuel]

well, freezing coud also be an symptome of poisoning some poisons could lead to shivering...

[EHM-1366 Themis]

Correction, the circles were anti-clockwise. This means that if somebody was trying to find LGAV and land the plane he/she was most likely sitting at the left seat and making left turns provides better view to the person sitting aleft. But I think I 've gone too far by now, I'm sure there are many points left in the way to make any kind of assumption till now... :s

[EHM-0005 Maarten]

Poisonned oxygen is only possible when breathing through a mask. The oxygen that is going through the airco is the same for both cabin and flight deck. Passengers poisonned by the oxygen coming from the lose mask of the commander is impossible.

At this moment, I stick to the malfunction of an oxygen system. We can only speculate about poisonning.

Also the plane doesn't seem to have crashed due to run out of fuel.

You are right, the aircraft did not crash due to low fuel. The descent that resulted in the crash was most likely caused by the co-pilot lying unconsiousness on the yoke. This caused an override of the autopilot.

The F16 pilots reported that at sometime they saw two people in the cockpit, presumably trying to take control of the plane.

This is the first time I hear this, so I can't say a lot about it. This is most likely speculation by the media.

If this is right (and this is the only thing I am going to say about it) then it could be passengers too. [--> Pilots have bad oxygen from their oxygen system -> commander gets out the cockpit to get fresh air -> Passengers see what is happening and go to the cockpit, because they are unsure about the pilots

Could the two clockwise circles over LGAV be executed by autopilot or someone else tried to take control and land the airplane?

I am not aware of these facts, so I can't say anything about it.

[EHM-1366 Themis]

well, freezing coud also be an symptome of poisoning some poisons could lead to shivering...

Well, its true. Or, maybe the captains were starting feeling dizzy-unconfortable-sweating and assumed that there is something wrong with the airconditioning. Before they left Larnaca control they reported some problem with the airconditioner...it was the last contact they had with a ground station

[EHM-1366 Themis]

If this is right (and this is the only thing I am going to say about it) then it could be passengers too. [--> Pilots have bad oxygen from their oxygen system -> commander gets out the cockpit to get fresh air -> Passengers see what is happening and go to the cockpit, because they are unsure about the pilots

That's what I believe.

[EHM-0005 Maarten]

I think we can scrap immediate poisonning due to food, because they were not in the stadium that food was being served.

[EHM-1366 Themis]

I don't know exactly when they reported that airconditioning problem, if it was 20 mins after departing, it is enough time for the 737 to reach cruise alt and start serving refreshments.

[EHM-0005 Maarten]

... but not for the pilots . I have never seen any pilot that wanted his food while he still had to finish something (even paperwork)

[EHM-0005 Maarten]

I just read the offical announcement from a Greek official telling that the two F16 pilots saw 2 unknown occupants trying to take control of the aircraft. He told that they could not be identified as passengers nor terrorists.

As I said before, I stick to the idea that the pilots were incapable to handle the aircraft.

[EHM-1366 Themis]

but if this is the case the airconditioning problem follows the refreshments. First they reach cruise alt, they order their refreshments, and then they feel uncomfortable (they suppose the airconditioning is not cooling enough). That makes sense why the passengers were feeling cold, and maybe that's the reason why the captain went out to check if the passengers cabin had the same problem too.

[EHM-0005 Maarten]

The captain had already turned blue (hypoxia, poisonning) when he left the cockpit, so he wasn't doing anything consiousness.

[edit]
Shivering due to poisonning (freeze-a-like) is possible, but unlikely. The bodies of the occupants were frozen according to someone who saw the whole thing happening from the ground. Terribble accident

[EHM-1366 Themis]

I just read the offical announcement from a Greek official telling that the two F16 pilots saw 2 unknown occupants trying to take control of the aircraft. He told that they could not be identified as passengers nor terrorists.

That's what I heard a couple of hours ago, and therefore assumed the plane crashed because someone tried to land it and forced the A/P off.
The plane was making circles anti-clock wise(to the left). At the last turn it passed over KEA and then crashed near KOTRONI.
The person who tried to land the plane could be making circles to find the airport, and was turning to the left because it gives better view when sitting to the left.
The sure is that by that time the A/P via FMS navigated the plane till it reached near LGAV and then someone tried to take control. But as soon as he toughes the controls the A/P is automatically disengaged

[EHM-0005 Maarten]

Could be possible indeed. How terrible, you're lost for sure when you have to take control of an aircraft but you're not pilot.

Have you heard anything about the altitude of the aircraft at the moment of interception by the fighters?

[EHM-1366 Themis]

They intercepted the plane over Naxos LGNX, which is around 90 nm inbound LGAV. At that point the plane should had started descending in order to be at FL150 or so for the STAR. Therefore they should be somewhere around FL300 and FL250 if I'm correct

[EHM-0005 Maarten]

mmm, ok. I am going to bed now. Let's wait tomorrow's news brings...