what if autopilot had option to press some button every 5 or 10 minutes to check if pilot is conscious, if not it would automatically descend to FL100 or even FL50? Maybe it could save the day.

Respect your opinion CS, but "IMO, both he and atc contributed to the accident." is a rash statement. ATC clearly wasn't aware of the severity of the developing situation, and its possible that the PIC had a fault with the oxygen supple or system - we don't know.

FWIW the aircraft N900KN ferried through Prestwick on delivery on 14 March this year. A friend sent me a picture of it at PIK but won't post as copyright isn't mine.

KKoran, not always so, my aircraft, {an eight pax presurized twin} if the cabin diff, along with cabin alt are not at the EXACT figures given in the POH, at ten thousand feet, then one can have a seal leak or poorly seated DV window along with a leak in a controll run seal, I have yet to see a new pilot on type pick up these small clues on climb out, a tenth of a needle width is all one may get in these cases, however if one checks every five thousand it will soon be obvious that going any higher is not a smart thing to do, but I have seen very few private pilots who seem to pay enough atention to these clues, or pick up on the indications.One country I lived and flew in for a few years a pilot wishing to fly above ten thousand had to visit the decompresion chamber for training every five years, over here, unles one is ex military pilots have no actual experience of hypoxia symptoms. And by the way, on at least one light presurized aircraft the emergency O2 valve can only be turned on from outside the cockpit.

We flew half a day with multiple legs in a B737 with crew oxygen showing normal. The next morning on first flight of day checks donned the oxygen masks and checked flow. The pressure went from normal to zero. Maintenance had replaced the oxygen bottle the day before prior to our flights and forgot to turn the bottle on.

The bottle was in the fwd cargo compartment and bags were loaded so they had to be removed to turn the bottle on.

If that happened with an airliner think how easy it would be for it to happen in someones private airplane.

If this happened on our flight we would have immediately initiated an emergency descent, then called ATC if we had an explosive decompression. If it was not explosive then deal with it as required.

It is ATC's job to separate traffic, not read a pilots mind on how serious the situation is and compromise his traffic separation.

<<It is ATC's job to separate traffic, not read a pilots mind on how serious the situation is and compromise his traffic separation.>>

Precisely. Well said.

A hypoxia alert has been issued by the Air Safety Institute:

According to this AOPA article, the pilot was chairman of the TBM Owners and Pilots Association and had flown a reported 5000 hours in TBM aircraft, so he should have been more than familiar with the systems. His wife, reportedly on board, was also a pilot and would most likely have tried to take over in case her husband was having personal medical problems.

TBM owner?s group chair crashes after becoming unresponsive - AOPA

We are trained to recognise hypoxia over the airwaves, and how quickly it can set in at different altitudes. But we can't know what's going on in the cockpit if we aren't told. If the pilot realised he had a pressurisation problem then he should have descended without clearance, and, if he had time, squawked 77 and told ATC.

If separation is lost due to an emergency, we face no sanction, and are permitted to use 500 ft emergency vertical separation if warrated

Back in the 60's part of the training at Hamble was a visit to the decompression chamber.

In the 35 years that followed in BEA/BA never had an engine failure but had three emergency descents. The hypoxia training taught me, especially on a two crew aircraft, that playing with the system in manual mode that took the total attention of one pilot was a non-starter. Any failure in auto mode get down into the thick air and let the engineers play with it.

We may never know what was going on in the Socata but why was there no urgency with regard to the descent request. The odd "magic" word would at least have got the controller "in the loop"

Having worked as a 'Distress and Diversion' controller in the UK I have dealt with many emergencies. One of the problems that controllers routinely face is the unwillingness of pilots to actually declare an emergency. The job of ATC is stated as maintaining: "The Safe, Expeditious and Orderly flow of air traffic." Safety is NOT solely limited to deconfliction of aircraft it is anything that the controller can do to maintain safety of the aircraft this includes (but is not limited to) flow management, weather alerts, closing hazardous airspace, and of course responding to and providing all necessary assistance to aircraft in distress - and yes, deconfliction and sequencing.

In this case, the pilot had asked to descend, said there was something wrong, then started being less than coherent. If a controller cannot understand from that set of transmissions that there is a probable oxygen problem then perhaps a little retraining is in order. What the controller SHOULD have done as soon as it became apparent that the pilot was not with it, is just transmit "<<Callsign>> expedite descent 8000 ft " and repeat that --don't even worry about the altimeter setting that can come once the pilot is responding more sensibly. Then as the aircraft is descending things can be sorted out like deviating other traffic. Meanwhile your D-Side should be giving a point out to the low sector alerting them of the probable emergency that is dropping into their airspace on your sector's frequency.

Pilots should also stop being reticent about declaring an emergency. If you have a busy or slow controller and you are indirect about a problem then you will not get any priority. Put your transponder to 7700 that wakes up _everyone_ including the center supervisors, declare PAN or MAYDAY then everyone will clear out of your way and provide assistance. You will not get assistance with a 'Houston we have a problem' transmission on a busy frequency. If you have a pressurization and oxygen failure then it is imperative you descend immediately in the few seconds of useful consciousness you have left using the FMC if possible to give a safe level off. By all means turn 30 degrees off an air route but you do not have time to be clever, you will just become comatose and that is the wrong choice for everyone. At FL280 even at 4000fpm you are going to take 3 to 4 minutes to get to a level with sufficient oxygen to wake you up as you will probably lose consciousness on the way down.

In this case had the pilot transmitted: "MAYDAY MAYDAY MAYDAY this is <callsign> in emergency descent to 8000ft with a pressurization problem - standby" then squawked 7700. He and his wife would almost certainly have been alive today.

Hypoxia
 

Hypoxia doesn't feel bad. You're not short of breath, you're lungs aren't burning. Everyone has slightly different symptoms, but most subjects just feel slightly warm and tingly. You are either astounded or unaware of your worsening incapacitation and how poorly you're performing, and very soon after it begins to happen, its usually too late.

If you fly in the thin air, and have never experienced your personal symptoms of hypoxia, you really owe it to yourself to get yourself a chamber ride.

I think a receiving an "high altitude endorsement" without a chamber ride is dumb. We've had two fatal GA hypoxia accidents in the US in the past week.

For US certificated pilots, you can ride for free at the FAA's CAMI in Oklahoma City; book early as there's usually a wait. There are similar good deals in other countries.

Precisely, and at this point the only thing he should have to decide is whether the descent should be clean or dirty. Either way he'd probably be coming downhill at around a mile a minute.

It's not quite that easy. The system would need to be linked to some sort of terrain database. Remember, in some parts of the US (and other parts of the world) 5,000 feet, and even 10,000 feet, willl put the plane underground.

In the Gulfstream G550/450 and G650 models there is an "EDM" or Emergency Descent Mode on the Autopilot.

Quite simply if the aircraft is above FL400 (normal cruise altitudes are FL410 to FL510 for these models) with the autopilot engaged and a "Cabin pressure low" CAS msg is generated, the aircraft turns 90 degrees to the left, automatically engages the auto throttles if not already engaged, and commences a FLCH descent to 15,000ft at Mmo/Vmo, levels off at 15,000 feet and sets speed to 250 knots indicated.

Thinking it would be beneficial if a system similar to this was more widely used on other automated aircraft.

oxygen use in gliders is routine
 

At Aboyne, the Deeside Gliding Club, oxygen is carried, used with a mask or with canula. Above 12,000 in mountain wave, flying solo, I decided to turn it on; with a choice of settings of either 2 or 4, thought it would be a good idea to put flow half way, assuming that would give 3 per minute, or however the flow is calculated. Actually, this gave me no oxygen at all! so from there to 15,000 feet I was breathing the ambient air.

The safety system at the gliding club is that once you tell them you are going on oxygen, they radio you every five or ten minutes to find out if you are still talking sense....I was sharply told that it would be a good idea to descend right away, and my understanding of the system was given a thorough overhaul before the next attempt at diamond height. Got it eventually, at 20,300'. But don't really care to tempt fate again, so having the gain of height award I now settle for sensible heights, no more than 12,000, thank you.

But gliders fly up to 50,000' in mountain wave these days. Pressurised systems and suits, I believe.

Anyone know what indications a TBM would display for loss of cabin pressure?
. . . In all older Boeing’s, an audible alarm would sound for cabin altitudes above +10,000 ft, and such alarm could NOT be silenced until cabin altitude returned below that threshold. I would expect that manufacture certification requirements are strict.

Many airlines have mandatory memory checklist items for such anomalies. . . Ours was to descend immediately to a breathable altitude, only after putting on oxygen masks at 100% oxygen, retarding thrust levers, and deploying speed-brakes (ATC to be advised later).

Do GA pilots have/ use/ are disciplined in such mandatory memory items?

Well since "GA" covers most if not all flying which isn't part 121 airline or military, answers may vary among different segments of GA.


I can say with assurance that the part 135 jet charter segment trains loss of pressurization scenarios at each simulator training event, at least in my own experience. It was definitely specified in the last part 142 training center agreement I reviewed in it's entirety. As per our approved company training program of course. This was for my last part 135.293/297 recurrent training and checking event. I know it's included in type rating training for non air-carrier bizjet and turboprop pilots too.

Since the TBM is a light prop airplane and does not require a type rating, then the training and endorsement required by 61.31(g) (one-time) may be the only "hard" regulatory requirement. However I find it highly unlikely that any part 142 simulator training center would leave it out of an initial or recurrent simulator training event. Pilots/owners of such aircraft may find their insurance carriers "encourage" ;) their insured to partake of such training as well. Or so I've been told by more than one owner of a high altitude turboprop.



westhawk