A/P ALT re-clearance

[ZAGORFLY]

Thinking at the re-discussed Cipriot 737 disaster As I wrote one year ago this incident has been an insult to the aviation industry research to the safety.

We all know the danger and the benefits of the high altitude flying and oxygen is there to supply the people during those 20-25 minutes more than enough time necessary to descend 30,000 feet.

Dual oxygen system is fitted on our aircraft to secure the crew segregation with a separate Oxygen supply (if you test properly, as you should, the mask before departure to be sure that the system in operative)

How come that an FMS/Autopilot system that is able to perform an auto land is unable to detect "abnormal cabin ALT over and extended time"? How come we do have CAB ALT able to deploy PASS OXY at 14,000 automatically but unable to set a different alarm if the climb continues? That is what I call and insult to this technology design.

is a logic suggestion to design a software that will “re-clear” the autopilot to descend to safe ALT or to prevent a further climb? All those unnecessary deaths will be better remembered.

I am truly amazed and surprised to read that after Golfer Payne and the Cyprus disaster still airplane can’t recover from a such dual crew incapacitation.

[Bluebat_CZ]

I personaly think that the A/P feature that you are referring to might be usefull in cases of decompression at hight altitudes without a descent being initiated by the pilots - assuming that for some reason they did not have enough time to don the mask and went incapacitated (not following the 'above FL410' requirement to wear oxygen mask) - then of course you would need to solve the problem of where the aircraft 'puts down' itself? But other cases - for example like in the case of the Cypriot 737 that continued climbing I think it would be sufficient that another cabin alt horn sound would go off again (while being silenced at FL100) when the cabin alt reached eg FL140. All of the onboard systems assume that the pilots do their job properly (unfortunately not the case of the Cypriot plane)...

[RYR-738-JOCKEY]

If the crew had put on their oxy masks, this would never had happen. So what if the only way of silencing the horn was to pull out the masks of their casing? Too much automation will reduce the pilots to brainless monkeys.

[mustafagander]

Any A/P software which automatically descends the A/C to a lower alt, say FL140 or so, could be mighty exciting on the routes over Afghanistan or L888 over southern China!!!

IMHO what is needed is a very loud alarm which, as RYR posted, requires the oxy masks to be removed from their stowages. Remember that hypoxia is very subtle and, typically, sufferers are unaware of their predicament so it needs to be very simple and unable to be defeated.

[ZAGORFLY]

An "auto-desend" in obviously flyable skyes offcourse! in the fmc database are the rescrictions to keep you far from chinese or afgane peaks.
but keeping the plane below 14000 ft would give you the chance to weak up from your initial potential hypoxia status.

[mustafagander]

No Zagor, we MUST have an alarm! The consequences of an auto descent below LSA don't bear thinking about. Failure is not an option. A loud, undefeatable alarm is the only safe option. Think of the failure case - you may get a headache from the noise. I can live with that - how about the failure case puts you into a hill? Not for me!!!

[DAL2728]

So was this 737 cruising at FL410 before the incident occured? They must have been either light as a feather or strapped for cash for fuel costs to be that high!


It is a requirement for pilots to wear their oxygen masks above FL410 during normal operations?