Use of oxygen when one pilot is on break
Most of the newer bizjets do have "emergency descent mode" as an autopilot function. Cabin > 13,500-ish, plane >F250, autopilot coupled, and the A/P does a ninety degree turn off course, throttles idle and speed goes to Mmo/Vmo and levels off at F150-ish. Details depend on manufacturer. On Global Express, EDM can also be manually selected by the crew.
GF
GF
Life isn't fair, I guess. There is an assumption that the pilots will respond, disconnect the autopilot and level off at a safe altitude. What are the odds of both pilots being disabled, the plane depressurizing over the highest terrain? Pretty remote and 15,000 covers a remarkable area of the globe--I'd guess 98%. The idea is to get the plane moving down in a controlled fashion.
GF
GF
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Another FAA Overkill? No!
I have to believe that this is good policy: At or above FL250, a temporary 'solo pilot' must use supplemental O2, (my words, not theirs).
Think it through... If already on O2 for a couple of minutes, it saves a lot of time - when - if something happens. How long are those 'Pee Breaks?' Other then the direct business and a polite word to a FA or two, can it take more than five minutes? Most QD masks are not uncomfortable and certainly not for five minutes or so. For Gawd's sake, just do it and be safe. The odds are always in your favor, but do it anyway. If/when, it is one less detail to deal with... Five minutes won't kill you, with or without a FA as a cockpit monitor. Use the O2!!!
Think it through... If already on O2 for a couple of minutes, it saves a lot of time - when - if something happens. How long are those 'Pee Breaks?' Other then the direct business and a polite word to a FA or two, can it take more than five minutes? Most QD masks are not uncomfortable and certainly not for five minutes or so. For Gawd's sake, just do it and be safe. The odds are always in your favor, but do it anyway. If/when, it is one less detail to deal with... Five minutes won't kill you, with or without a FA as a cockpit monitor. Use the O2!!!
Couple of points,
First, It's there to protect the case of pilot incapacitation, better than flying off as a zombie.
Second, it is easily overridden by the pilot. Disconnect the A/P and it's done.
Third, it does NOT deploy speedbrakes, so the descent will not be really rapid giving more time for pilot intervention. I'd guess none of the planes so equipped would descend from F450 Ag much greater than 1500 fpm clean.
Last, to the best of my knowledge, it's hasn't yet been used for real.
GF
First, It's there to protect the case of pilot incapacitation, better than flying off as a zombie.
Second, it is easily overridden by the pilot. Disconnect the A/P and it's done.
Third, it does NOT deploy speedbrakes, so the descent will not be really rapid giving more time for pilot intervention. I'd guess none of the planes so equipped would descend from F450 Ag much greater than 1500 fpm clean.
Last, to the best of my knowledge, it's hasn't yet been used for real.
GF
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For a good example of how this may actually work, read the NTSB report on American Trans Air 406, May 12, 1996.
The mask needs to work for two cases: depressurization and smoke in the cockpit. Several years ago, my MD-80 started filling up with smoke from the AC system at FL 370. That is not the time to find out that the mask is not properly adjusted, the hose is tangled, or the mask mike doesn't work.
I preflight the mask every time I get into a new airplane. It is the old quick-donning mask, so the headbands need adjusting, etc. I routinely (probably 3 times a year) find a mask with an inoperative mask mike.
I can't speak to the full face masks, but the Eros mask we had on the 757/767 was easily preflighted in the box. However, we are required to use it above 250, and I used to find them occasionally tangled or packed in a way that would be a problem if you needed the thing quickly. I found that they were very easy to replace once you practiced it...which, if you use it regularly, you can do.
One of the advantages of using them regularly is that you will be that much more comfortable with donning, setting up comm, and flying that way, so that the day you really, really need to do that you won't be swimming in glue.
That said, I also distinctly remember coming back up from my crew break approaching Land's End to find the O2 pressure on the status page reading zero. It only took me a couple of nanoseconds to realize that the reason for that was that I had left the emergency lever on when I preflighted it back at JFK, and we probably hadn't had any O2 since we were about number 4 for takeoff. That could be avoided by not preflighting the mask, of course, but you could also preflight it carefully and correctly. Fortunately, I am not a skydiver.
I also discovered, fortunately in the sim, that the smoke goggles provided by a particular company did not fit over my drugstore readers. Another useful check to make once in a while.
Bottom line is you're gonna get one shot at getting it right on the day you need it. Whether you are required to use it above 250, 350 or not at all, always preflighting it and periodically using it can't do anything but make your day go better when that moment springs...
The mask needs to work for two cases: depressurization and smoke in the cockpit. Several years ago, my MD-80 started filling up with smoke from the AC system at FL 370. That is not the time to find out that the mask is not properly adjusted, the hose is tangled, or the mask mike doesn't work.
I preflight the mask every time I get into a new airplane. It is the old quick-donning mask, so the headbands need adjusting, etc. I routinely (probably 3 times a year) find a mask with an inoperative mask mike.
I can't speak to the full face masks, but the Eros mask we had on the 757/767 was easily preflighted in the box. However, we are required to use it above 250, and I used to find them occasionally tangled or packed in a way that would be a problem if you needed the thing quickly. I found that they were very easy to replace once you practiced it...which, if you use it regularly, you can do.
One of the advantages of using them regularly is that you will be that much more comfortable with donning, setting up comm, and flying that way, so that the day you really, really need to do that you won't be swimming in glue.
That said, I also distinctly remember coming back up from my crew break approaching Land's End to find the O2 pressure on the status page reading zero. It only took me a couple of nanoseconds to realize that the reason for that was that I had left the emergency lever on when I preflighted it back at JFK, and we probably hadn't had any O2 since we were about number 4 for takeoff. That could be avoided by not preflighting the mask, of course, but you could also preflight it carefully and correctly. Fortunately, I am not a skydiver.
I also discovered, fortunately in the sim, that the smoke goggles provided by a particular company did not fit over my drugstore readers. Another useful check to make once in a while.
Bottom line is you're gonna get one shot at getting it right on the day you need it. Whether you are required to use it above 250, 350 or not at all, always preflighting it and periodically using it can't do anything but make your day go better when that moment springs...
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Mansfield,
Great points, my thoughts exactly as I read this thread. I ensure my co-pilots wear the mask when I leave the cockpit - how? I always let them use the Lav first. They then see that I have put my mask on before they leave and know I expect them to do the same (they find the antiseptic swabs nearby when they come back)
I can't say how many FO's: fumbled putting the mask on, fumbled setting up the audio controls for intra cockpit communication and fumbled ATC transmissions. Twice in the last 20 years, last time about 2 years ago I had to put the mask on for real - cabin pressure loss and smoke. It wasn't easy-peasy but it wasn't the horrendous distraction it could have been.
Captains lead by example, Captains mentor by example. That young fellow or young lady in your right seat is going to fly you around some day as the Captain.
Great points, my thoughts exactly as I read this thread. I ensure my co-pilots wear the mask when I leave the cockpit - how? I always let them use the Lav first. They then see that I have put my mask on before they leave and know I expect them to do the same (they find the antiseptic swabs nearby when they come back)
I can't say how many FO's: fumbled putting the mask on, fumbled setting up the audio controls for intra cockpit communication and fumbled ATC transmissions. Twice in the last 20 years, last time about 2 years ago I had to put the mask on for real - cabin pressure loss and smoke. It wasn't easy-peasy but it wasn't the horrendous distraction it could have been.
Captains lead by example, Captains mentor by example. That young fellow or young lady in your right seat is going to fly you around some day as the Captain.
