F-22 Raptor missing in Alaska - search underway . . .
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Jem60,
Different Tomcat. The tailfin that was washed up came from a jet lost in the Gulf of Mexico!
I believe it now adorns the wall of a certain RAF pilot who once flew the 'cat on exchange.
Different Tomcat. The tailfin that was washed up came from a jet lost in the Gulf of Mexico!
I believe it now adorns the wall of a certain RAF pilot who once flew the 'cat on exchange.
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Oxygen-Generating Systems Under Investigation
The U.S. Air Force is investigating whether the On-Board Oxygen Generating System (OBOGS) found on several U.S. Air Force warplanes, including the F-22 Raptor, might be defective.
"Air Force operational commanders have temporarily restricted F-22 flight operations to an altitude at or below 25,000 feet for routine training missions" ...
"Air Combat Command is conducting an investigation to assess on-board oxygen generating systems on several platforms, including the F-22,...
A Lockheed Martin spokesman confirmed that the restriction has been in place ever since an F-22 based at Elmendorf Air Force Base, Alaska, crashed in November 2010.
One Air Force source said that an OBOGS malfunction might have been responsible for the incident...
{published: 24 Mar 2011}
Aircraft Oxygen-Generating Systems Under Investigation
Ecce Homo! Loquitur...
DefenseNews: USAF Board Blames Pilot, Not Oxygen System, in F-22 Crash
A U.S. Air Force Accident Investigation Board (AIB) report is blaming the Nov. 16, 2010, crash of an F-22 Raptor on Capt. Jeff "Bong" Haney - despite a malfunction of the jet's bleed air intakes, which caused an automatic shutdown of multiple aircraft systems including the primary oxygen system.
An aircraft's engine bleed air system extracts air from a jet engine's compressor section to generate power and supply gases for an aircraft's life support system, among other systems.
The AIB report confirms Defense News' Sept. 8 report, in which an industry source and a pilot both said that a bleed air malfunction had caused the crash by shutting down the oxygen system. The AIB, however, places the blame on Haney for not reacting quickly enough to activate the jet's emergency oxygen system or recover from a dive he inadvertently entered into as he struggled to regain his air supply.
"I find the cause of the mishap was the MP's [mishap pilot] failure to recognize and initiate a timely dive recovery due to channelized attention, breakdown of visual scan and unrecognized spatial disorientation," wrote Brig. Gen. James Browne, president of the AIB.
The F-22's On-board Oxygen Generating System (OBOGS), which supplies breathing air to the pilot and has been under investigation for most of the year, did not malfunction and wasn't a contributing factor, the report said. But the crucial device did shut down because of the bleed-air problem. In September, Air Force Chief of Staff Gen. Norton Schwartz said oxygen had not played any role in the crash.
The report notes that "the MP most likely experienced a sense similar to suffocation," but also rules out hypoxia as contribution factor however despite the shut down of the oxygen system.
"Due to the high affinity of oxygen to hemoglobin, the MP would have had adequate blood oxygen supply after the OBOGS failed," the AIB report states. "It was concluded that the late recognition of the MA's [mishap aircraft's] unusual attitude and appropriate corrective actions attempted by the MP demonstrates that hypoxia was not a factor in this mishap."
A knowledgeable source agreed that Haney would not have fully succumbed to hypoxia, but would have been showing symptoms. Despite what the report says, the source said hypoxia would have played a role even if the pilot had not been rendered unconscious.
"The rate at which he descended, though, he would have been at a hypoxia-safe altitude within time to have not fully succumbed to hypoxia and should have only had symptoms versus unconsciousness," the source said.
The environmental control system (ECS), air cycle system, On-Board Inert Gas Generating System (OBIGGS), cabin pressure and OBOGS were all shut down when the aircraft's computer shut off the malfunctioning bleed-air system, according to the AIB report. The bleed-air system remains closed in the event of a malfunction to prevent fires.
The aircraft's memory unit showed "partial pressure to the MP's [mishap pilot] oxygen stopped shortly after 19:42:37 L, which would lead to severely restricted breathing," the accident report reads.
However, Haney did retain enough consciousness to attempt a recovery from a steep dive the aircraft entered into right before the crash. It was too late, however, as the Raptor impacted the ground a scant three seconds later.
However, Haney did not manage to active the Emergency Oxygen System (EOS) to supply him with air, which he needed to do in case the OBOGS shutdown. As the report notes "severely restricted breathing is a physiological symptom which would have prompted the [mishap pilot] to active the EOS."
Pilots have said that the emergency oxygen supply is notoriously difficult to use in the Raptor.
The AIB report states that as Haney struggled for air, "he channelized his attention on restoring airflow to his oxygen mask."
As Haney fought to restore his oxygen supply, he inadvertently began to roll the aircraft and his "visual scan" of the aircraft's instruments and external situation broke down. He entered into a state of "unrecognized spatial disorientation," according to the AIB report. The aircraft rolled 240 degrees and dropped to a 53 degree nose down attitude. Had Haney not been distracted by trying to breathe, he would have recognized the problem, the report reads. Haney didn't make any intentional control inputs for some 39 seconds.
"The fact that the [mishap pilot] went from a controlled flight regime to an unusual attitude and did not take corrective actions for 30 seconds suggests he had unrecognized spatial disorientation," the AIB report reads. "At 19:42:24L the [mishap pilot] recognized the [mishap aircraft's] position and attempted to perform a dive recovery."
Ultimately, the Air Force chose to blame Haney rather than attribute the crash to a malfunctioning bleed-air system and a difficult to use emergency oxygen supply.
"The fact that the [mishap pilot] went from a controlled flight regime to an unusual attitude and did not take corrective actions for 30 seconds suggests he had unrecognized spatial disorientation," the AIB report reads. "At 19:42:24L the [mishap pilot] recognized the [mishap aircraft's] position and attempted to perform a dive recovery."
Ultimately, the Air Force chose to blame Haney rather than attribute the crash to a malfunctioning bleed-air system and a difficult to use emergency oxygen supply.
Ultimately, the Air Force chose to blame Haney rather than attribute the crash to a malfunctioning bleed-air system and a difficult to use emergency oxygen supply.
Ergonomics?
Flight regime? I'd love to have a look at the AIB ...
If the emer oxygen system is hard to use, and that difficulty is known, what training is done to overcome that diffiuclty? When you are in extremis, you typically revert back to your training.
Was he in a flight regime where he could not trim S & L while troubleshooting? The info leaves a lot missing.
Thanks for the updates, even if troubling.
It would be interesting to see the F-22 PCL and boldface for an OBOGS malfunction to understand what went amiss here.
Had Haney not been distracted by trying to breathe, he would have recognized the problem, the report reads.
The environmental control system (ECS), air cycle system, On-Board Inert Gas Generating System (OBIGGS), cabin pressure and OBOGS were all shut down when the aircraft's computer shut off the malfunctioning bleed-air system, according to the AIB report.
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Flight regime? I'd love to have a look at the AIB ...
what's the point in having all those clever computers if they screw you up when things get tough?
Ultimately, the Air Force chose to blame Haney rather than attribute the crash to a malfunctioning bleed-air system and a difficult to use emergency oxygen supply
From reading elsewhere, it is a requirement of certain accident reports (may apply to USAF as well?) to attribute a single "cause" to an accident. One also lists contributory factors. Where the combination of factors all combine e.g. removing any one of them would have prevented the accident, then you list the "proximate" (IIRC) factor, which in practice means the final one. Provided my recollection is correct, then this is the correct cause, since the pilot did attempt to recover albeit too late.
Where Defence News has it wrong is to say:
the Air Force chose to blame Haney
NoD
Do a Hover - it avoids G
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It sounds as if the pilot was focused on trying to breathe - and looking at the Rube Goldberg set-up for activating the emergency oxygen system, I'm not surprised that it never got turned on.
Per Ardua ad Astraeus
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How hard would it be to unclip the mask with all the headgear on?
My comment on computers referred to why the 'computer' could not be programmed to turn on the emerg oxy (I appreciate the existing mechanism). I assume there is no inward relief valve on the mask?
My comment on computers referred to why the 'computer' could not be programmed to turn on the emerg oxy (I appreciate the existing mechanism). I assume there is no inward relief valve on the mask?
"For a ha`porth of Tar ,the ship was lost"....Ergonomics is obviously not a strong point in assessing `emergency Controls` under duress....fumbling around ,looking for a 10cent `coke-can ring-pull` (sorry,at F-22 prices it probably cost $1000)..
Presumably the ejection seat has some form of independent oxygen supply?
Therefore, the next time a F-22 pilot has breathing difficulties all he has to do is eject, and the company/USAF will see the cost benefits of an easy to use emergency oxygen system, as opposed to losing a $150M aircraft....
Of course the tragedy here, which my comments are not intended to belittle, is the loss of life caused by the poor design of an essential safety feature!!
Therefore, the next time a F-22 pilot has breathing difficulties all he has to do is eject, and the company/USAF will see the cost benefits of an easy to use emergency oxygen system, as opposed to losing a $150M aircraft....
Of course the tragedy here, which my comments are not intended to belittle, is the loss of life caused by the poor design of an essential safety feature!!
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Biggus,
"Therefore, the next time a F-22 pilot has breathing difficulties all he has to do is eject, and the company/USAF will see the cost benefits of an easy to use emergency oxygen system, as opposed to losing a $150M aircraft...."
Wouldn't they see both ?
If the pilot ejects, they lose the aircraft as well / anyway ?
Or is the F22 that good it has a RTB by itself mode
"Therefore, the next time a F-22 pilot has breathing difficulties all he has to do is eject, and the company/USAF will see the cost benefits of an easy to use emergency oxygen system, as opposed to losing a $150M aircraft...."
Wouldn't they see both ?
If the pilot ejects, they lose the aircraft as well / anyway ?
Or is the F22 that good it has a RTB by itself mode
No doubt my English let me down.....
What I was trying to say was that an easy to use emergency oxygen system would save them the cost involved in losing a $150M aircraft, let alone save lives.....
But I would guess that you knew that was what I was trying to say!!
What I was trying to say was that an easy to use emergency oxygen system would save them the cost involved in losing a $150M aircraft, let alone save lives.....
But I would guess that you knew that was what I was trying to say!!
Post 47 & 48
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How hard would it be to unclip the mask with all the headgear on?
However, nor was it part of the drill. He was at 50K', pressurisation gone as well as Oxy, I am sure from your WIWOL days that getting rid of your Oxy mask was not high on your priority list
In retrospect, he was descending (too) rapdily, the Cabin Alt was only rising slowly, and dumping the mask would have relieved the immediate symptoms... but that requires thinking outside the box and with 20:20 hindisght (IMHO).Think through the UPS 744 out of DXB. Again, inability to breath, and possibly poor training / drills / AEA led to various issues (IIRC, Capt did toggle 100% correctly, so now could not breathe - P2 did not toggle, so could breath, albeit the contaminated cockpit air).
could not be programmed to turn on the emerg oxy (I appreciate the existing mechanism).
When compared to the MB single pull, accessible, visible, toggle ball 
I assume there is no inward relief valve on the mask?
NoD