Socata TBM-700 Unresponsive Over Cuba

If the cabin pressure drops suddenly, or if the cabin altitude is too high and oxygen isn't flowing, why not have the autopilot descend to, say, FL80 after sounding an alarm and waiting 30 seconds?

Basically a dead man's switch / watchdog timer that engages under hypoxic conditions.

 

http://archive-server.liveatc.net/kgso/ZTL-GSO-Sep-05-2014-1400Z.mp3

 

Thomas- That would get you killed in major parts of the West.

 

I believe the newer Cirrus has a interactive AP that will go lower if there's no pilot input for a few minutes. It was on a recent similar situation where the pilot went through the DC FRZ. There is a vert nav chart showing step descents, but it didn't help.

 

Sure, but crew killed by prolonged hypoxic conditions is guaranteed to end up in terrain.

Whatever the specifics, it seems like there are a set of conditions that are almost deterministically incapacitating. Rapid depressurization at high altitude + no oxygen, for example. Would not descent to some preset level, which could be overriden by a conscious pilot, present the lesser risk?

 

The thing that keeps knocking at my head is that there is something wrong with the pressurization systems in these fancy airplanes. How many times is this going to happen? This has never happened in a commercial airliner so why has it happened three or four times now in the pressurized private airplanes? You can go through all the emergency procedures discussions ad infinitum but until the cause of the failure is determined it's going to continue. O2 mask above 12K.

 

What are your criteria? There have been rapid decompression incidents on commercial airliners caused by cargo doors, metal fatigue, corrosion, etc.

 

The Commander that I fly has a light which comes on at 12,000 feet cabin altitude. No horn. Most (all?) of the jets I've flown had a light and a horn.

A friend of mine had a dual flameout in a Lear 25, at 41,000 feet. Of course, when the engines are not running, no air comes into the cabin. He descended as quickly as he could, since you can't air start a CJ-610 about 25,000 (if I remember correctly).

The relevant part is that he has the ATC tape (I've heard it), and throughout his transmissions you can hear the cabin altitude horn going "meep meep meep." Yet he said that until he heard the ATC tape, he had no idea it was going off.

All the lights and horns in the world won't save you if you aren't listening. Has anyone on here seen the YouTube video of the French guys landing gear up in the Trinidad? You can hear the gear horn all the way down. Didn't help them.

Incidentally, my friend in the Learjet got down to 25,000 feet, relit the engines, and flew on to his destination. He had a lot of experience with flameouts...

 

Very rarely do these incidents happen to two pilot crews. Ironically, this might have been one of those cases, since apparently both this gentleman and his wife were qualified in the airplane.

 

I was not thinking about rapid decompression. I was thinking of the slow unannounced failure or leak that causes an undetected lack of O2. I admit that I'm not familiar with the small high altitude equipment. I simply feel that there is something wrong either with the system or the warning methods.

 

One thing that strikes me odd about the news coverage:
They say that the son confirmed that the parents were both killed.
But the aircraft hadn't yet been found at that point.

The media needs to show a little judgment about publishing things from a phone interview with a distraught family member in the middle of a crisis.

I thought that was a lesson they should have learned from the disgraceful badgering of family members during the Apollo 13 flight.

 

It's down....oil slick spotted...R.I.P to both of them, leaving three children.

 

This sounds absolutely right...

He reported "indication of malfunction" and requested to descend, and while Traffic Control was clearing a lower airspace, 'they said' he got more and more confused..
Last transmission was his Call Letters, twice repeated.

Then silence.....cruise control....he never changed altitude...it disappeared from radar within five minutes of the range calculation...

She knew how to fly it, as well....

 

REALLY good post....."Hey, coming thru!!"

...and be really heads up on visual...better than dead.

FAA would fine you into next week, most likely...

 

No not really. The FARs give a pilot authority to break any and all rules to the extent required to deal with the emergency.

You just have to be ready to explain yourself.


Mark

 

Happened ona greek 737 a few years back. But yes its unusual.

 

It does precisely that in my Citation Mustang except the G1000 reads the highest sector you have flight planned and descends to the concurrent MOCA.

 

What's the difference between MOCA and MSA?

 

It's been awhile, but I'll take a stab at it. MOCA is minimum obstacle clearance altitude. Basically you won't hit terra firma at MOCA. I believe it gives you 2000 ft clearance in mountainous areas and 1000 in non mountainous areas. But you may not have radio reception in order to navigate the sector. This is based on VOR navigation. Just about everybody has a GPS of some sort with them nowadays, so navigation is still available. MEA is minimum enroute altitude. It's usually higher than MOCA as it ensures radio navigation.

MSA should mean Minimum Sector Altitude. It provided 1000 clearance within 25 miles of a specified navaid on instrument approaches. But I'm guessing you're referring to minimum safe altitude. I don't believe there's an accepted term (ICAO) for minimum safe altitude. But basically the idea is to fly 1000 ft above congested areas and 500 ft above non congested areas as a minimum. I believe it also says you can fly as low as you want over sparsely populated ares so long as you are 500 ft away from a structure or person.

If I remember that correctly, you can legally buzz the beach as low as you want provided you're 500 ft offshore.

It's been awhile, so don't take my word for these definitions or for buzzing the beach. Check the FARs!

 

In the 747 classic, the cabin altitude warning is the exact same sound as the takeoff configuration warning. I believe the older 737s are like this to. Anyways, there have been flights while climbing out of 10,000 ft the warning goes off. Pilots have wondered why they are getting a takeoff configuration warning at such a high altitude. You wouldn't have much time to wonder as the passenger oxygen masks drop at around 14000 ft I believe.

Oh, the reason for most of these cases was failure to turn the air conditioning packs on. Takeoffs in the older jets required the packs to be off in order to get full takeoff power. Even the 747-400 needs the packs off under certain conditions. Typically the packs are turned on after climb power is set (1500 ft). Of course you can get busy on the radio about that time.

Just some trivia that has led to passenger masks deploying in the past.....

 

Jamaica searchers have found floating wreckage.

 

Hey Lou, If there are at least two people on the beach the FAA will likely call it an open air assembly of persons and you had better be 2000ft off shore. Also don't do anything resembling an "Abrupt change in attitude" or you will get gigged for acrobatics below 1500.

Basically, if it's fun, it's illegal. Unless you have a Christian Eagle of course!

 

X plane austin wears a little thingie on this finger that measures o2 levels. What about these devices?

Flying on Supplemental Oxygen

 

They are called pulse oxymeters and they measure the O2 saturation in the blood. It used to be a very costly thing, but the little finger clamp is a good quick check to insure your have good O2 levels. The sad part is, that if your O2 saturation falls, all the ones I've seen, have no alarm.

It would be much more valuable if there was an audible and physical alarm if it falls below setpoint.

 

Lou- We had two settings in the F-111 for pressurization, combat and normal. If you passed through about FL200 and the cabin pressure warning light came on, it meant one of two things: it was peacetime and the aircraft commander mis-set the switch, or you were in a war and that little light was normal.