Crew Confusion in Helios crash

[J.O.]

By Don Phillips - International Herald Tribune

PARIS

The crew members of a Cypriot airliner that crashed Aug. 14 near Athens became confused by a series of alarms as the plane climbed, failing to recognize that the cabin was not pressurizing until they grew mentally disoriented because of lack of oxygen and passed out, according to several people connected with the investigation.

Complicating the cockpit confusion, neither the German pilot nor the young, inexperienced Cypriot co-pilot could speak the same language fluently, and each had difficulty understanding how the other spoke English, the worldwide language of air traffic control.

A total of 121 people were killed in the crash after the plane climbed and flew on autopilot, circling near Athens as it was programmed to do until one engine stopped running because of a lack of fuel. The sudden imbalance of power, with only one engine operating, caused the autopilot to disengage and the plane to begin its final descent.

The Greek authorities have made cryptic statements hinting at oxygen problems but have so far not announced the full findings of investigators.

The people interviewed for this article agreed to do so on condition that they not be identified because none are official spokesmen for the investigation and because of political sensitivities arising from a Cypriot plane crashing in Greece.

Investigators pieced together the story of the crash from numerous sources. In the wreckage, they found the first solid clues - the pressurization valve and an air outflow valve set incorrectly. Air traffic control tapes provided information on the confusion in the cockpit.

The plane had a sophisticated new flight data recorder that provided a wealth of information. There were maintenance records from the night before, and investigators interviewed the mechanics who worked on the plane.

Among other things, the investigators determined that the pilot was not in his seat because he was up trying to solve a problem that turned out to be not the greatest threat facing him.

The plane that crashed, a Boeing 737, underwent maintenance the night before. The maintenance crew apparently left a pressurization controller rotary knob out of place, according to the officials connected to the investigation, and the crew did not catch the mistake during preflight checks the next day. This meant that the plane could not pressurize.

At 10,000 feet, or 3,000 meters, as designed, an alarm went off to warn the crew that the plane would not pressurize. However, the crew members mistakenly thought that the alarm horn was a warning to tell them that their controls were not set properly for takeoff, the officials said.

The same horn is used for both conditions, although it will sound for takeoff configuration only while the plane is still on the ground.

The crew continued the climb on autopilot. At 14,000 feet, oxygen masks deployed as designed and a master caution light illuminated in the cockpit. Another alarm sounded at about the same time on an unrelated matter, warning that there was insufficient cooling air in the compartment housing avionics equipment.

The radio tapes showed that this created tremendous confusion in the cockpit. Normally an aircraft cabin is held at 8,000 feet pressure, so the crew at over 14,000 feet would already be experiencing some disorientation because of a lack of oxygen.

During this time, the German captain and the Cypriot co-pilot discovered they had no common language and that their English, while good enough for normal air traffic control purposes, was not good enough for complicated technical conversation in fixing the problem.

The crew members called the maintenance base in Cyprus and were told that the circuit breaker to turn off the loud new alarm was in a cabinet behind the captain. The captain got up from his seat to look for the circuit breaker, apparently ignoring the confused co-pilot.

As the plane continued to climb on autopilot, the air grew so thin that the crew became seriously impaired. The captain passed out first on the floor of the cockpit, followed by the co-pilot, who remained in his seat, according to the officials.

The autopilot did as it was programmed to do, flying the plane at 34,000 feet to Athens and entering a holding pattern. It remained in a long circling pattern, shadowed by Greek military jets, until fuel ran low and one engine quit.

Boeing, the maker of the plane, issued a notice shortly after the crash to airlines that it would revise flight crew training manuals to stress to crews that they must understand how the various warning systems work and what to do about them.

The notice stresses that the takeoff configuration warning horn will not sound under any circumstances after the plane has left the ground.

The same horn will then be used only for a cabin altitude warning. The company notice said there had been other instances of confusion over the horn by pilots.

"Confusion between the cabin altitude warning horn and the takeoff configuration warning horn can be resolved if the crew remembers that the takeoff configuration warning horn is only armed when the airplane is on the ground," the notice said. "If this horn is activated in flight, it indicates that the cabin altitude has reached 10,000 feet."

[ChicoChico]

I guess we can see how important is it to do this?

1. In the event of a rapid depressurization I will

assume control and call “RAPID DEPRESSURIZATION

DRILL”.

2. I will don my oxygen mask and communicate on

the interphone: “CAPTAIN ON OXYGEN”.

[Moon The Loon]

I guess we can see how important it is to do this?

1. In the event of a rapid depressurization I will

assume control and call “RAPID DEPRESSURIZATION

DRILL”.

2. I will don my oxygen mask and communicate on

the interphone: “CAPTAIN ON OXYGEN”.

During my brief 2 1/2 year stint in a JAR operated environment, I have little faith in their belief, let alone enforcement in SOP's such as you've highlighted here.

It makes just too much sense

[ChicoChico]

MTL

Huh?

JAR?

Don't believe in SOP to don o2 mask???

CC

[handyman]

I guess we can see how important is it to do this?

1. In the event of a rapid depressurization I will

assume control and call “RAPID DEPRESSURIZATION

DRILL”.

2. I will don my oxygen mask and communicate on

the interphone: “CAPTAIN ON OXYGEN”.

Hey Chico and da moon,

This was NOT a rapid depressurization! In comparison, a rapid decompression is very easy to identify compared to a lack of pressurization if a mental block leads you to believe the horn is caused by something else. as per any accidents, many errors were made from the ground up and any one properly identified could have broken the chain of events to this accident.

[Guest stones]

I would agree with CP. They should have noticed it on the takeoff roll when the wind noise inside the cabin from lack of pressurization (max .125) would have been different. Then their ears popping should have been another give away. All they had to do was hit the Alt Hold button. Hind sight is always 20/20.

[ChicoChico]

Not trying to armchair quarterback this flight at all - but for the grace of God and all.

However the SOP in the event of Rapid Depressurization covers the quote unquote "pressurization PROBLEM" and there for the answer again (in this situation is to PUT ON YOUR OXYGEN MASK.

My point is that we should not diminish the importance of donning an O2 mask immediately, not to be critical of this particular flight.

CC

[J.O.]

Spot on Chico-squared. Seems to me it would be much better to don an un-needed mask, than to leave off a needed one. There have been cabin and cockpit smoke incidents in the past as well where crew have been reluctant to put on their masks. Makes you wonder why ...

[Moon The Loon]

MTL

Huh?

JAR?

Don't believe in SOP to don o2 mask???

CC

WWT ( ), hold on a minute - I was referring to this scenario with the comment about SOP's:

The crew continued the climb on autopilot. At 14,000 feet, oxygen masks deployed as designed and a master caution light illuminated in the cockpit. Another alarm sounded at about the same time on an unrelated matter, warning that there was insufficient cooling air in the compartment housing avionics equipment.

The radio tapes showed that this created tremendous confusion in the cockpit. Normally an aircraft cabin is held at 8,000 feet pressure, so the crew at over 14,000 feet would already be experiencing some disorientation because of a lack of oxygen.

During this time, the German captain and the Cypriot co-pilot discovered they had no common language and that their English, while good enough for normal air traffic control purposes, was not good enough for complicated technical conversation in fixing the problem.

The crew members called the maintenance base in Cyprus and were told that the circuit breaker to turn off the loud new alarm was in a cabinet behind the captain. The captain got up from his seat to look for the circuit breaker, apparently ignoring the confused co-pilot.

As the plane continued to climb on autopilot, the air grew so thin that the crew became seriously impaired. The captain passed out first on the floor of the cockpit, followed by the co-pilot, who remained in his seat, according to the officials.

Now granted, this may be a scenario deduced by the Greek officials and not what necessarily happened. My point is and was that the type of discipline we see in most North American carriers is not as predominant in Europe. Not to mention the many years behind they remain with CRM. In many places I've flown throughout Europe and Africa, the captain is still god. Not a good situation. In my opinion.

[handyman]

Stones,

I agree with ya but the chain started even before the take-off roll.

...had the maintenance staff returned switches back to the normal position,

...had the crew done a accurate flow checking switches prior to start.

[J.O.]

How much of the confusion would have been mitigated had this crew been able to communicate effectively? I wonder if the report will give this aspect any attention. This is one of the consequences of employment rules in the new Europe, where a citizen of any European country has the right to work in any other. Not that I'm against having as many job opportunities as possible, but I do think a crew should be able to communicate in a more meaningful way than just the ATC lingo and the checklists. I recently heard some pretty scary ATC communications involving some UK & Irish low cost operators. Based on what I was hearing, I had to wonder if the crew in the flight deck was able to communicate with each other better than the way they did with ATC.

[Guest Touchdown]

J.O.....

Food for thought....You ask why crews might not don their masks. A possibility is exactly what you guys are referring to here...Communication ! Putting on masks cuts down the crew's ability to communicate by a large factor. You can try as you may but between all the Darth Vadering between breaths (even with the inhale cutout on the Embraer) you still get a lot of unneccessary noise not to mention the fogging/sweat problem they create.

I am in no way not advocating (double negative ? ) putting on your mask during any smoke, but our QRH for lav smoke for example has the first item as Masks don, 100% and establish communications IF REQUIRED. It gives the crews an out if they choose not to put them on for communication purposes for example. That may be why crews don't do it. Of course there could be toxic smoke that can incapacitate someone without a smell or visual (as carbon monoxide can do) so masks might be prudent in all cases....

As I said, food for thought.

Cheers Touchdown

[J.O.]

You make a good point, TD. I agree that most cockpit oxygen masks do not offer an easy mode of communications. I guess my safety officer colours were showing through. Still, common sense tells me that it's a whole lot easier to communicate in a breathable environment, than it is to lose consciousness in one that's not "human friendly". I remember a departure one day with a mutual acquaintance of ours. We took off after deicing and just after rotation, we were presented with some very nasty fumes, enough to make my eyes water and my throat burn. To this day I still wonder why we didn't think to put our masks on. Yes we were pretty sure as to the source, but we were not truly sure as to how long it would last. Fortunately, the duration was pretty short. Still, if that were to happen to me again, I would definitely don my mask, even if only for a minute or two.

[mo32a]

J.O.....

but our QRH for lav smoke for example has the first item as Masks don, 100% and establish communications IF REQUIRED. It gives the crews an out if they choose not to put them on for communication purposes for example.

Or do they mean

1. Put on your mask!

2. Establish Communication - if required.

[Guest Touchdown]

J.O.

Right as always. Better to be gesturing and alive, than no mask on and unable to speak !

Cheers Touchdown