F-22 Raptor missing in Alaska - search underway . . .
I know I'm dim, but to re-ask BEagle's question: why didn't emergency oxygen flow automatically, with a manual 'OFF' rather than a manual 'ON' selection being needed. Fire risk?
Happy to be tutored here.
CG
PS I know the 'actual' answer- it's not designed to!
Happy to be tutored here.
CG
PS I know the 'actual' answer- it's not designed to!
PPRuNe Person
Join Date: Jun 2001
Location: see roster
Posts: 1,268
Likes: 0
Received 0 Likes
on
0 Posts
The report is interesting reading, especially the graph towards the end which shows the poor chap initiated recovery 3 seconds too late 
I suppose "fly the aircraft" is easy to say when you are not in the jet, at night, disoriented and struggling to breathe and encumbered by NVGs, trying to work out what's wrong
Not sure where I heard "task fixation leads to disorientation" but it seems relevant here. Take care out there chaps/esses.
I suppose "fly the aircraft" is easy to say when you are not in the jet, at night, disoriented and struggling to breathe and encumbered by NVGs, trying to work out what's wrong
Not sure where I heard "task fixation leads to disorientation" but it seems relevant here. Take care out there chaps/esses.
Has anyone seen what the actual cabin altitude reached when the event occurred? How is the F-22 canopy sealed to the fuselage?
So there you are, flying a complex sortie, wearing extreme cold weather gear for the first time that year - and it's night. You're supercruising at above 50K when the oxygen supply fails and the cabin pressure fails.....
What about the resulting mist and condensation from the drop in cabin pressure? I remember that being quite significant in the old chambers at Luffenham even doing a simple 25K-45K in 3 sec bang.
You're now groping blindly for a difficult to find ring in cumbersome clothing, in the dark and very probably with a misted up visor....and then you start to suffocate.
The aircraft starts to descend at over 50 000ft/min at supersonic speed......
RIP - and I don't think the pilot should be considered blameworthy in any respect. If you're suffocating, can't see and can't find the poorly-designed EmO2 ring, you might well begin to feel a sense of panic, no matter how good a fighter pilot you are.
If other pilots complained about the design of the EmO2 ring-pull, why the hell wasn't urgent modification action taken?
So there you are, flying a complex sortie, wearing extreme cold weather gear for the first time that year - and it's night. You're supercruising at above 50K when the oxygen supply fails and the cabin pressure fails.....
What about the resulting mist and condensation from the drop in cabin pressure? I remember that being quite significant in the old chambers at Luffenham even doing a simple 25K-45K in 3 sec bang.
You're now groping blindly for a difficult to find ring in cumbersome clothing, in the dark and very probably with a misted up visor....and then you start to suffocate.
The aircraft starts to descend at over 50 000ft/min at supersonic speed......
RIP - and I don't think the pilot should be considered blameworthy in any respect. If you're suffocating, can't see and can't find the poorly-designed EmO2 ring, you might well begin to feel a sense of panic, no matter how good a fighter pilot you are.
If other pilots complained about the design of the EmO2 ring-pull, why the hell wasn't urgent modification action taken?
Join Date: Jan 2001
Location: UK
Posts: 2,044
Likes: 0
Received 0 Likes
on
0 Posts
Has anyone seen what the actual cabin altitude reached when the event occurred? How is the F-22 canopy sealed to the fuselage?
What about the resulting mist and condensation from the drop in cabin pressure? I remember that being quite significant in the old chambers at Luffenham even doing a simple 25K-45K in 3 sec bang.
What about the resulting mist and condensation from the drop in cabin pressure? I remember that being quite significant in the old chambers at Luffenham even doing a simple 25K-45K in 3 sec bang.
I know I'm dim, but to re-ask BEagle's question: why didn't emergency oxygen flow automatically, with a manual 'OFF' rather than a manual 'ON' selection being needed. Fire risk?
PS I know the 'actual' answer- it's not designed to!
A deeper question might be that normal O2 systems are fairly independant of other aircraft systems, and have automatic functions e.g. decompression go to high flow / pressure breathing. Therefore the seat back-up is adequate.
However, OBOGS is tied in deeply to the aircraft systems, and more liable to failure. It might therefore be appropriate for there to be an aircraft emergency system that is more automatic, or at least simple to use? When I flew with OBOGS, it was pretty reliable IIRC, although pretty easy to generate intermittent false warnings - it correctly was a "top level" warning - but that in turn meant you tended to ignore it because it was so regular. I believe it was a factor in an accident when a top-level warning (Flaps?) was ignored in the belief it was the OBOGS (again...)
NoD
NoD, the mighty F-4 could mist up very easily at any level and you could get hailstorms inside a Hunter at times - not just because of rapid decompression. But that was due to the rather antiquated conditioning systems in such jets.
The F-22A cabin pressure warning doesn't seem to have been a low pressure warning, more that it was 'outside the schedule'.
If you're hot and sweaty and the cabin ECS fails, I'm pretty sure that it wouldn't take much to cause the visor to mist up, even if the cockpit itself didn't actually fill with mist.
The F-22A cabin pressure warning doesn't seem to have been a low pressure warning, more that it was 'outside the schedule'.
If you're hot and sweaty and the cabin ECS fails, I'm pretty sure that it wouldn't take much to cause the visor to mist up, even if the cockpit itself didn't actually fill with mist.
Join Date: Jan 2008
Location: UK
Posts: 1,515
Likes: 0
Received 0 Likes
on
0 Posts
Beags,
Good post.
The idea that performance of the pilot can be meaningfully analysed in these circumstances is absurd.
The instant any form of oxygen shortage impacts the brain a whole raft of physiological implications kick in...different in everybody and in each circumstance. They would have had to have had the poor chap wired up with all that crap the astronaults wear, with a squad of flight surgeons chewing it through in real time to get any useful data on how he was reacting...and even then it would count for little more than the square root of **** all.
I remember an occasion at North Luffenham when they blew the chamber with 8 of us on board for rapid decompression drills. Seven of us took our masks off and started chirping down from 100 (minus 7 each time as I recall) IAW the brief. The eighth took his mask off, glazed over and pitched foward out for the count (excuting a near perfect Glasgow Kiss on the onboard medic who was leaning into him, LOL). Seemed he suffered from some sort of shock reaction.
Aircraft and pilot lost due to malfunction...end of. RIP.
Good post.
The idea that performance of the pilot can be meaningfully analysed in these circumstances is absurd.
The instant any form of oxygen shortage impacts the brain a whole raft of physiological implications kick in...different in everybody and in each circumstance. They would have had to have had the poor chap wired up with all that crap the astronaults wear, with a squad of flight surgeons chewing it through in real time to get any useful data on how he was reacting...and even then it would count for little more than the square root of **** all.
I remember an occasion at North Luffenham when they blew the chamber with 8 of us on board for rapid decompression drills. Seven of us took our masks off and started chirping down from 100 (minus 7 each time as I recall) IAW the brief. The eighth took his mask off, glazed over and pitched foward out for the count (excuting a near perfect Glasgow Kiss on the onboard medic who was leaning into him, LOL). Seemed he suffered from some sort of shock reaction.
Aircraft and pilot lost due to malfunction...end of. RIP.
Those are all good points. I don't recall the USAF O2 mask causing suffocation with the supply switched off/failed. It is possible to move your jaw to break the seal and breathe round it. I would have thought hypoxia in that case. Of course my old F-15 kit has probably been superseded by something far more deadly.
Your point about the effects of panic through being unable to breathe is spot on. I do a lot of diving and recall an incident a couple of years back. Not pleasant and totally disproportionate to the reality of the situation. Certainly focusses the mind on a single issue. And not always the most important one!
Your point about the effects of panic through being unable to breathe is spot on. I do a lot of diving and recall an incident a couple of years back. Not pleasant and totally disproportionate to the reality of the situation. Certainly focusses the mind on a single issue. And not always the most important one!
Do a Hover - it avoids G
Join Date: Oct 1999
Location: Chichester West Sussex UK
Age: 91
Posts: 2,206
Likes: 0
Received 0 Likes
on
0 Posts
My generation were very happy to allow Pilot Error as a cause of accidents regardless of whether some aspect of the aircraft made life hard for the pilot.
However in today's more enlightened times given the information in the AIB report (there may be more that we don't have of course) I think to say this accident was pilot error is quite astonishing.
However in today's more enlightened times given the information in the AIB report (there may be more that we don't have of course) I think to say this accident was pilot error is quite astonishing.
Join Date: Apr 2009
Location: Hotel Gypsy
Posts: 2,821
Likes: 0
Received 0 Likes
on
0 Posts
It seems to me that our unfortunate pilot possibly made an understandable error of judgment when faced with a systems malfunction and associated design weakness. Bearing in mind the whole Mull Chinook discussion, the USAF analysis appears to be rather harsh. I wonder how F22 drivers feel. 
Join Date: Feb 2006
Location: Hanging off the end of a thread
Posts: 33,072
Received 2,940 Likes
on
1,252 Posts
Join Date: May 2011
Location: Malkin Tower
Posts: 847
Likes: 0
Received 0 Likes
on
0 Posts
Air Force Blames Pilot in Suspicious Stealth-Jet Crash | Danger Room | Wired.com
I think this sums up nicely what many of you are trying to say
I think this sums up nicely what many of you are trying to say
Join Date: Jan 2008
Location: Australia - South of where I'd like to be !
Age: 59
Posts: 4,261
Likes: 0
Received 0 Likes
on
0 Posts
I read the report but can't remember seeing anything about why the pilot failed to eject at the last minute ? I suspect I missed something.
Nigel, thanks for the link. 
500N
Is ejecting in a Mach 1.1 dive within the envelope for safe ejection?
It appears he was trying to get out of his Unusual Attitude all the way to the deck.
Is ejecting in a Mach 1.1 dive within the envelope for safe ejection?
It appears he was trying to get out of his Unusual Attitude all the way to the deck.
Per Ardua ad Astraeus
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes
on
0 Posts
Is ejecting in a Mach 1.1 dive within the envelope for safe ejection?