Recent content by Lord Muck

He may have already been hypoxic with diminished judgement when he made that first call. We shouldn't assume he was not.

This plane had the GFC700... That will try to keep the plane flying level as the speed bleeds off then it will disconnect at a certain minimum IAS. I would guess at that point the plane will slowly start descending. At that point without any further control inputs, the final outcome would depend...

What follows is total speculation so take it for what it's worth (not much): We don't know what happened but the pilot didn't like what he saw and decided he needed to get lower. Perhaps a high cabin altitude warning? For whatever reason he decided to not declare an emergency and did not...

That's why you put the oxygen mask on while you descend.

From the POH: Very easy to set up this emergency descent with the GFC700. Throttle goes to IDLE then use FLC to select the descent at 266 IAS if smooth or 178 IAS if rough according to this. EMERGENCY DESCENTS MAXIMUM RATE DESCENT FLY THE AIRPLANE 1 - Throttle . . . . . . . . . . ...

From the POH Front seats 1 - Take amask on the opposite seat side (pilot : R.H. side ; R.H. Front passenger : L.H. side) : draw it out of the stowage cup and uncoil tube totally. Press on the red side vanes to inflate the harness. Put the mask on the face. 2 - No smokes : 3-position...

Here is the TBM900 POH. http://www.tbm850.com/2014/images/tbm/pim/PIM_900R01.pdf

Yes or you can use FLC and dial in the speed you want to descend at (although I wouldn't do that). Best to set it up for a high descent rate using the emergency descent procedure (speed brakes, gear down, or whatever it is for the TBM900). And reduce power of course.

Very well said.

So possibly wasn't set correctly? There should still be a cabin altitude warning though.

It's an emergency mask probably have to push aside when talking through your headset/mic. Doesn't mean he didn't have a mask on.

Pure speculation of course... He may have gone onto oxygen. Perhaps it wasn't working properly. Perhaps he didn't activate it correctly. I don't know how much time the TBM900 emergency oxygen gives you but it is probably 15 minutes or better. One scenario is he thought he was good and had...

Yes for sure. There will be an emergency descent procedure that he would have had to practice every year as part of recurrent training.

Call me chicken but I wouldn't take that chance. I'd go down to where I can breathe in case it lets go completely. "Center, N123 has lost cabin pressure and is doing an emergency descent to 12,000"

He asked to go to FL180 which is still not safe if he had lost cabin pressure. He didn't say what the problem was. It seems likely it was lost of cabin pressure especially if the windows were frosted over.