Listening to the radio exchange, it appears as if he knew he had a problem and was asking for clearance to descend. To my untutored ear it sound as if ATC were not too helpful.

I disagree, it was a routine conversation, pilot asked for lower altitude because he said something was wrong, I don't recall exact words. He did not declare emergency or anything like that, controller can't read pilot's mind. In absence of clear-cut emergency controller had to coordinate with other traffic to let him descend. By the way, he had right to make emergency descend without even asking anybody for permission if he felt he was in dire situation.

Sad situation... there is a chance that by the time the pilot realised there was a pressurisation problem in the aircraft, he was already suffering the early effects of hypoxia. Had he been fully alert he might have called a pan-pan or a mayday... but sadly he did not.

I do wonder though, if the controller should have at least asked if the pilot if he wanted to declare a pan pan or mayday. It might have prompted the pilot to declare and emergency (which we know now, it was). In the minute or so of consciousness the pilot might have had left, he might have been able to set up for a decent and the controller could have got on with clearing other traffic. It does look like the controller either did not realise the seriousness of the situation, or decided to take the easy option.

May I ask where I can hear that conversation? I'd like to get a handle on the opinion of the controller being less than helpful/taking the easy option.

After listening to this audio if I were the controller I could not get any sense of urgency in this pilot's voice, not a hint of serious trouble. Controller is simultaneously handling a dozen or more aircraft, they can't possibly guess what's going aboard some aircraft. It is really not controller's job to think for a pilot, unfortunately there were many accidents because pilot failed to communicate clearly. This pilot was in command of that aircraft and as pilot in command he has legal right to deviate immediately from any assigned altitude, speed, heading, etc if he thinks the situation warrants it.

Clunckdriver,

Given that the pilot was responding normally an hour and a half after departure, it would seem any pressurization issue occurred during cruise. I doubt a check passing 10,000 feet would have identified a problem.

A few observations that may or may not be relevant to this accident.

Pressurization or no, at FL250. a functional oxygen mask should be all that is needed to stay at FL250 until ATC feels more cooperative.

But if the oxygen mask isn't working..... you might get what happened here.
A pilot not declaring an emergency followed by an unconscious pilot.

With the valve off at the tank, but pressure still in the lines, you might get what seems to be a good functional check on pre-flight.

Aviation is still very unforgiving of oversights.

@ GAPSTER the ATC com is available at: Aviation Audio Clips | LiveATC.net)

I for one, cant understand why the controller dont ask that extra question in this case. Sure he has multiple aircrafts to handle but only one that's indicating a problem. Why not ask; "What type of problem do you have?" Most ATC-staff surely should be edjucated in how hypoxia-challenged pilots really arent able to state the serverity of their situation by now? :sad:

Gapster

Pilot: 'We need to descend' - CNN.com Video

Airplane was very new . . . March 2014 Airworthiness Certification.

Here's a timeline of the flight:
Flight Track Log ? N900KN ? 05-Sep-2014 ? KROC - KAPF ? FlightAware

EDT Alt Crs
8:26:00 1,100 215 First radar return
8:46:00 28,000 199 Cruise flight
10:04:00 28,000 193 Problem indicated. Cleared to descend to FL250
10:05:00 27,000 193
10:06:00 25,000 172 Levelled off. Turning 30 degrees left
10:07:00 25,000 164 Turn complete. Course and altitude remain for the duration of flight
14:11:00 25,000 207 Last return. Heading and altitude erratic over the last 2 minutes

And a summary of the tape:
http://archive-server.liveatc.net/kg...2014-1400Z.mp3

Offset Alt
0:04:17 FL280 Pilot: "We need to descend to about 180. We have an indication that is not (?) correct in the plane"
0:04:22 FL280 ATC: "Standby"
0:04:30 FL280 ATC: "Descend and Maintain FL250"
0:04:33 Pilot: "250 we need to get lower"
0:04:37 ATC: "Working on that"
0:04:52 ATC: "If you have to get down, 0KN, turn 30 degrees left"
0:04:58 Pilot: "30 left"
0:06:35 FL250 ATC: (Broken) "FL200" (Assumed it was clearance given)
0:06:42 FL250 Pilot: "FL200 0KN"
0:07:15 FL250 ATC: "Cleared direct Taylor"
0:07:30 FL250 ATC: (Repeats) "Cleared direct Taylor"
0:07:33 FL250 Pilot: "Direct Taylor 0KN"
0:08:05 FL250 ATC: "N900KN Copy that altitude 200"
0:08:10 FL250 Pilot: (Unintelligible)
0:08:37 FL250 ATC: "N900KN Descend and Maintain FL200 and cleared direct Taylor"
0:08:42 FL250 Pilot: (Slow voice - last contact) "Kilo November 900 Kilo November"
0:09:50 FL250 ATC: "Understand FL200, FL200 for 900KN"
0:10:10 FL250 ATC: "TBM, TBM, Zero Kilo November, descend and maintain FL200"
0:11:49 FL250 ATC: "Zero Kilo November, if you hear this, transmit and ident"
0:12:15 FL250 ATC: (Attempts contact through other air traffic)

And the time of useful consciousness:
https://en.wikipedia.org/wiki/Time_o..._consciousness

So:

- Within 2.5 minutes of reporting the problem at FL280, descending to FL250, he ceased responding to the ATC directive to descend to FL200.
- After a further 2 minutes, still at FL250, his voice was very groggy and it was the last response given.

Hypoxia is so insidious. Very sad.

And what is here to correct?? Also the last I checked such pressurized private aircraft are in operation around the world.

It was a TBM 900

If I have read this thread correctly - but I accept that I could have misread the details - it is reported that the controller instructed the pilots to remain at FL250. It seems not to have occurred to that controller that the pilots might not able to think clearly due to hyopoxia.

Surely the controller should have given a very firm instruction to descend? I have to wonder whether the controller could now conceivably face manslaughter charges?


Are air traffic controllers given any training about the effects of high altitude flying? As a young Air Force pilot in the 1960s, I had experience in a decompression chamber. That experience served me well when I some years later I had oxygen failure in a glider in mountain wave at 20,000 feet. Again I stand corrected, but I don't think today's civilian pilots who have had no previous military experience have even been near a decompression chamber

Had the controller been given adequate training for this extremely rare occurence, I would be in full agreement.

As it is, an imperfect, pragmatic system is operating. In my early Prooning days, I was shouted down for suggesting that the Tower, seeing a Wheels-up approach, did not warn the PIC and should have done.
" Not their responsibility! it's down to the PIC " the idea that ayou can take a "jobsworth" attitude and sit back and watch someone "crash and burn" is alien to me. Heck, if your best mate got infatuated with a 2-timing ripoff ratbag, you'd warn them, wouldn't you? :}
The PIC was just that....at his age and experience, in charge of a pressurised (sophisticated) Aircraft and being an authoritative buisinessman, one would have hoped his leadership skills would have allowed him to TELL ATC what he was doing....Also, of course, is the issue of Oxy management and the fact the aircraft was still in the "shakedown" phase of it's life.
Sad, preventable, IMO, both he and atc contributed to the accident. According to the transcript, he knew he had a problem and what it was....His training and recent transition to that aircraft, should have made him very aware of the hypoxia risk....it wasn't communicated to ATC.
the only consolation, is that they died peacefully. there are a lot worse ways to go. any Aviator must be aware of that.