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Despite bleed air failure and multiple system shutdown, bleed air system not blamed in crash

Now that its investigation is complete, the USAF has come back and handed down its decision on what caused the pilot of an F-22 Raptor to crash his aircraft in November 2010. According to sources and other pilots, the issue that led to the death of Capt. Jeff "Bong" Haney was a malfunction of the Raptor's bleed air intakes.
 
The report has now been issued and according to the USAF Accident Investigation Board, the cause of the accident was Haney, not the malfunctioning bleed air system in the stricken Raptor. The AIB found that while the bleed air system on the F-22 had failed, Haney didn’t react quickly enough to save the aircraft.
 
President of the AIB, Brig. Gen. James Browne wrote in the AIB report, "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."
 
Fingers were pointed early on at a failure of the On-board Oxygen Generating System or OBOGS as a cause of the accident. The accident report has determined that the OBOGS was functioning and was not a contributing factor to the accident. However, the OBOGS did shut down due to the bleed air problem the F-22 encountered.
 
The report read, "The MP most likely experienced a sense similar to suffocation." Despite that statement, the report also rules out hypoxia as a contributing factor to the accident. The report continues, "Due to the high affinity of oxygen to hemoglobin, the MP would have had adequate blood oxygen supply after the OBOGS failed. 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."
 
Defense News cites a source that claims that Haney would not have succumbed to hypoxia fully, though he would have had symptoms. The source notes that the hypoxia would have been a contributing factor even if the pilot were still conscious. Along with the OBOGS system on the stricken Raptor, the environmental control system, air cycle system, and On-board Inert Gas Generating System as well as cabin pressure were also shut down.
 
The recovered aircraft memory unit reportedly showed that the "partial pressure to the MP's [mishap pilot] oxygen stopped shortly after 19:42:37 L, which would lead to severely restricted breathing."
 
Haney was conscious enough to attempt to recover from the steep dive his Raptor was in right before the crash. The F-22 hit the ground three seconds after Haney first attempted to recover. The report notes that for 39 seconds Haney did nothing to address the flight condition of his aircraft.
 
The report reads, "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. At 19:42:24L the [mishap pilot] recognized the [mishap aircraft's] position and attempted to perform a dive recovery."
 
This was the second F-22 lost in service since the aircraft went operational. In March of 2009, another Raptor crashed killing the pilot. This accident was a contributing factor to the Raptor stand down that lasted months.
 
This week the final F-22 Raptor rolled off the assembly line and will replace the aircraft lost in the fatal crash that took Haney's life.

Source: Defense News



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Negative Dynamic Control
By simian pete on 12/16/2011 10:28:09 AM , Rating: 3
So if the pilot had enough time to correct (A BIG IF) even though he was experiencing "suffocation" then could the Raptor have other "aerodynamic" problems ?

Maybe Pilot induced oscillation or Oscillation induced by a faulty control system ? Maybe ? Or could the Raptor specs be overrated, flying outside it's "envelope" ( i.e. maybe 60,000 feet altitude is to high ?) ...

You just wonder what the heck is wrong -- Anyhow, I'm just speculating. Then Air Force engineers/technicians have mucho smarts. They will probably figure it all out ....

Once the bugs are solved they should build some more Raptors, like another 400 at least .... get the assembly line going again !




RE: Negative Dynamic Control
By rlandess on 12/16/2011 11:25:40 AM , Rating: 2
quote:
So if the pilot had enough time to correct (A BIG IF)


The article states that the pilot did nothing for 39 seconds. It seems to me that what they are saying is that the pilot failed to follow protocol and get to a safe altitude for 39 seconds, then took a steep dive in the last 3 seconds.

39 seconds is a long time.

I'm surprised pilots don't get an emergency air supply for flight testing. Then if the plane goes haywire or HAL tries to kill you you can just pop the mask on and concentrate on landing safely.


RE: Negative Dynamic Control
By Solandri on 12/16/2011 12:14:14 PM , Rating: 5
According to the report, he was at over 50,000 feet when the oxygen generator cut out and the plane lost pressure. At that altitude and pressure (about 1/10th sea level pressure), even breathing 100% oxygen you're having to cope with less than half the oxygen you get at sea level (equivalent to breathing unassisted at about 18,000 feet). Without supplemental oxygen, you'll be unconscious within 10-15 seconds.

It sounds like he did the correct thing in those seconds - point the plane down so he could get to an altitude where he'd have enough oxygen to stay awake. But the rest of the flight reads like he fell unconscious (little to no input to the controls), and only woke up a few seconds before the crash (7.5g recovery maneuver). It really does seem like a whitewashing by blaming the pilot for failing to do anything while he was most likely unconscious.


RE: Negative Dynamic Control
By Reclaimer77 on 12/16/11, Rating: -1
RE: Negative Dynamic Control
By voodoochile123 on 12/16/11, Rating: -1
RE: Negative Dynamic Control
By voodoochile123 on 12/19/11, Rating: -1
By inperfectdarkness on 12/18/2011 5:22:12 PM , Rating: 3
this. as a flyer myself, i've done altitude chamber testing, and i can personally vouch for the effects of hypoxia on a person at 30,000 feet (chamber pressure). considering i was breathing 100% oxygen for 20-30 minutes prior to this, the argument for hemoglobin being able to compensate for the lack of o2 is simply hogwash.

it's one thing if the pilot is performing a 9-g maneuver and blacks out & noses the plane into terrain. it's quite another if he's flying a fairly benign profile at 50,000' and the same thing happens. FL 500 is very, very close to the altitudes that u2's fly at...and i can also speak to the dangers of hypoxia on u2 pilots whose oxygen systems have malfunctioned. TUC (time of useful consciousness) at 50,000 feet is less than 10 seconds. 10 seconds is next to non-existent when you don't even instantly recognize your own hypoxia; especially when you're tasked with 1. trying to correct the oxygen deficiency, 2. trying to lose altitude so you can increase your TUC or breathe normally on cabin pressure, 3. task-saturated, which further reduces the useful duration of oxygen (resting will increase your TUC, while vigorous activity will reduce it).

i really do smell a cover-up here. sad. how many more pilots and f-22's (which we already have fewer than we need) will we have to lose before the real issues are fixed? yes, pilot error is a factor in a majority of mishaps (fatal or otherwise)...yet this still smacks of quite a bit more than the USAF is letting on about.


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