causes of F-22 oxygen problem have been found

[Air Force Brat]

USAF pinpoints root cause of F-22 Raptor

is this little snippit new performance knowledge?:

""This is a unique airplane," Schwartz says. "You can pull 6Gs at 50,000ft. Tell me what other airplane, ever, can do that?""

This is a very capable aircraft, and it performance parameters are not common knowledge, its true performance is at the limit of a human pilots ability to operate it safely. It remains the most capable fighter aircraft ever fielded, and will likely maintain this status for some time.

 

[colay]

Well, the AF is confident that it has finally found the cause of the hypoxia-like symptoms experienced by some F-22 pilots, namely a valve in the anti-G vest.
Hopefully this is the case and they still carry through with the redesign of the handle of the O2 emergency supply which could be a challenge to activate under certain circumstances. Perhaps they may scrap plans to install a backup O2 system as well.

 

[Air Force Brat]

Well, the AF is confident that it has finally found the cause of the hypoxia-like symptoms experienced by some F-22 pilots, namely a valve in the anti-G vest.
Hopefully this is the case and they still carry through with the redesign of the handle of the O2 emergency supply which could be a challenge to activate under certain circumstances. Perhaps they may scrap plans to install a backup O2 system as well.

I could'nt agree with you more on the handle design, I think think the emergency O2 is a good idea as well. Gen Schwartz also mentioned the charcoal filter and that it was being eliminated immediately, so it was also a contributing factor. Gen Schwartz also empasized a new focus on bio-mechanical interface, stating that early attention to those factors had been relaxed as the years had passed, but that there would be a renewed focus in order to hopefully prevent the types of incidents experience by the F-22 pilots. 07/25/12 AFM Daily Report

 

[RobWilliams]

Actually JameLi they are suspecting the upper pressure vest, they were able to replicate a condition where the upper pressure vest does not deflate as it should, after the g's are reduced, it remained inflated and continued to squeeze the chest, much like being sat on by an elephant. Also, the latest standing order is to not wear the upper g suit vest for "normal ops", whatever that means, this from colays source, "Flight Global", and the Air Force Magazines, daily report. This was replicated in the centrifuge where they can bring the g's up to max and maintain it as long as needed and gradually reduce them. This seems to be a major factor as the fully inflated vest makes it nearly impossible to breath, more testing to come.

Looks like you're correct.

Panetta Lifts F-22 Raptor Flight Restrictions | Aviation & Air Force News at DefenceTalk

The Air Force found that a faulty valve “caused the vest to inflate and remain inflated under conditions where it was not designed to inflate, thereby causing breathing problems for some pilots,” Little said. “The garment has been suspended from flight since June.”

This problem was not identified during initial F-22 testing.

Second, the Air Force removed a canister filter from the oxygen delivery system, and that has increased the volume of air flowing to pilots. The service also is looking at improving the oxygen delivery hose and its connections.

Glad they found the problem, good to see the F-22 being rid of this buisness hanging over it. Who knows, out of this any developments made could benefit future designs so s'all good.

 

[colay]

More on the subject..
Air Force: There Never Was a 'Smoking Gun' for F-22 Problems - ABC News

It says that the AF will install an automatic backup Oxygen system on the Raptor. This would likely have prevented the Alaska crash when Capt. Haney apparently experienced difficulty engaging the manual backup. A plan to install a Ground Collision Avoidance System on the F-22 fleet is also in the cards, I believe.

 

[Zbigniew]

But didn't reports say the pilots sound like drunk and talked weird stuff before they went down?
When they had pressure on the lungs it might sound strange and like drunk but they wouldn't take strange things.

But maybe it was just the sound not what they said, don't remember exactly.

 

[RobWilliams]

But didn't reports say the pilots sound like drunk and talked weird stuff before they went down?
When they had pressure on the lungs it might sound strange and like drunk but they wouldn't take strange things.

But maybe it was just the sound not what they said, don't remember exactly.

Pressure on the lungs means inefficient breathing and therefore lack of oxygen to the brain, so the pilot would demonstrate symptons of hypoxia which would make them sound kinda drunk + they wouldn't be thinking straight.

Of course, what we consider 'normal' to say, the USAF might think of as alarming like - say - excessive "uhhh"-ing. Or something like that.

That's my interpretation of it anyway.

 

[Air Force Brat]

Pressure on the lungs means inefficient breathing and therefore lack of oxygen to the brain, so the pilot would demonstrate symptons of hypoxia which would make them sound kinda drunk + they wouldn't be thinking straight.

Of course, what we consider 'normal' to say, the USAF might think of as alarming like - say - excessive "uhhh"-ing. Or something like that.

That's my interpretation of it anyway.

The Air Force Magazines daily report 9/14/12, states that there has not been an incident since March 8, 2012, I think its safe to say that the breathing issues in general are hopefully resolved. Rob correct me if I'm wrong as this is from memory, but I do believe the Air Force had stated that Capt Haney's incident was unrelated? As I recall Capt. Haney's bird had just had two new engines installed and had a master overheat alarm, due to hot bleed air, which shut down numerous systems, but also the OBOGS, anyway rest in peace Capt Haney. I'm not sure that they were able to nail it down completely, I had read the full accident report posted on this forum, it is quite lengthy, I should look it up and read it again.

 

[RobWilliams]

The Air Force Magazines daily report 9/14/12, states that there has not been an incident since March 8, 2012, I think its safe to say that the breathing issues in general are hopefully resolved. Rob correct me if I'm wrong as this is from memory, but I do believe the Air Force had stated that Capt Haney's incident was unrelated? As I recall Capt. Haney's bird had just had two new engines installed and had a master overheat alarm, due to hot bleed air, which shut down numerous systems, but also the OBOGS, anyway rest in peace Capt Haney. I'm not sure that they were able to nail it down completely, I had read the full accident report posted on this forum, it is quite lengthy, I should look it up and read it again.

This is all from memory (because it's nearly midnight here and i'm too lazy), so it could easily be wrong.

But my understanding of that incident was that it was officially put down as pilot error for not being aware - and not recovering from - his aircraft rapidly losing altitude.

From the actual report, this is what was said about Hypoxia

Hypoxia was considered as a possible human factor. The MP had adequate oxygen supply until 19:42:37L. At that time, the pilot would have experienced restrictive breathing through the oxygen mask. Prior to OBOGS FAIL caution ICAW, the MP should have been receiving adequate supply of oxygen. Due to the high affinity of oxygen to hemoglobin, the MP would have had adequate reserve blood oxygen supply after the OBOGS failed. During the mishap sequence, the MP never activated the EOS or removed his oxygen mask. If the MP had been hypoxic due to the restrictive breathing, the condition would have persisted throughout the mishap and he would not have recovered consciousness to place the aft stick inputs to attempt dive recovery prior to impact. It was concluded that the late recognition of the MA’s unusual attitude and appropriate corrective actions attempted by the MP demonstrates that hypoxia was not a factor in this mishap.

http://usaf.aib.law.af.mil/ExecSum2011/F-22A_AK_16 Nov 10.pdf

I'm fairly sure at one point there was plenty of talk abouth im supposedly sounding "drunk" over the radio too, there's plenty of material on the web that points in that direction anyway.

 

[JameLi1986]

"One person beats the entire engineering staff of Lockheed Martin to solve the oxygen problem on the F22."

My first post was meant as sarcasm or questioning the theory that the oxygen problem was actually solved. There must be thousands of Lockheed Martin engineers working and trying to identify the root cause of the problem? Just don't see one person can solve this problem as he theorized?

Hey man. Delete this post and keep the 1st one will be a good choice. Here is why.

Hey guys. It's jamesLi here again. After so many months and the F-22's oxygen problem is still no totally addressed. You know why is this? Because I just don't have the phone No. of the F-22 project manager or some generals of USAF. If Give me 2 minutes to talk to some of these guys. I can make them get it right in minutes. any way the reason I am here back again to post is there is news came out saying I made it very right. Almost proved my theory in someway.
here it is go ahead and read this please:

seach this title : AF Still Reviewing Oxygen Levels for F-22 Cockpit | Military.com

"As the aircraft descends and the pilot puts eight Gs on the aircraft, the percentage of oxygen produced by the Obogs is reduced," the report says. "As the pilot reduces the G load, the Obogs begins to recover and then the percentage of oxygen produced by the Obogs is reduced again when the pilot reapplies the Gs."

The report says, "The amount of oxygen being produced does decrease to between 60 percent and 70 percent."

I am not an arrogant man. BUT I JUST WANT TO SAY A BARE TRUTH HERE: FOR THE f-22 oxygen problem. ONE CHINESE GUY HAD JUST BEAT THE ENTIRE LOCKHEED ENGINEERING TEAM in 3 minutes.

 

[RobWilliams]

Until I see an adequate theory that includes how the pilot somehow managed to inhale propane, CO, synthetic oils and antifreeze i'm never going to be 100% convinced by any theory about the hypoxia-like syndromes.

Then really with the most amount of honesty I can bring, no matter how you preface it, the statement "One Chinese guy just beat the entire Lockheed Martin engineering team in 3 minutes" is still hugely arrogant in my opinion. I'm sure if I was making some comment about me being better than all of Chengdu that you'd be equally as critical of such a statement.

It then leads onto if your knowledge of aircraft engineering is just so vast you know more than the whole of LockMart then how come you're not working for Shenyang or Chengdu - an industry which (considering your apparent knowledge) you're guaranteed to make more money than any other job you could want?

Not to mention that chances are most of the material in regards to this issue isn't in the public domain.

 

[SpudmanWP]

Read the sign: Don't feed the trolls


@JameLi1986
View attachment 5636

 

[RobWilliams]

Very true, but sometimes it can equally be just as interesting to feed them and see just what comes out next.

Surely you've had at least one experience of repeatedly poking a troll to see what goodies they drop

 

[Air Force Brat]

Hey man. Delete this post and keep the 1st one will be a good choice. Here is why.

Hey guys. It's jamesLi here again. After so many months and the F-22's oxygen problem is still no totally addressed. You know why is this? Because I just don't have the phone No. of the F-22 project manager or some generals of USAF. If Give me 2 minutes to talk to some of these guys. I can make them get it right in minutes. any way the reason I am here back again to post is there is news came out saying I made it very right. Almost proved my theory in someway.
here it is go ahead and read this please:

seach this title : AF Still Reviewing Oxygen Levels for F-22 Cockpit | Military.com

"As the aircraft descends and the pilot puts eight Gs on the aircraft, the percentage of oxygen produced by the Obogs is reduced," the report says. "As the pilot reduces the G load, the Obogs begins to recover and then the percentage of oxygen produced by the Obogs is reduced again when the pilot reapplies the Gs."

The report says, "The amount of oxygen being produced does decrease to between 60 percent and 70 percent."

I am not an arrogant man. BUT I JUST WANT TO SAY A BARE TRUTH HERE: FOR THE f-22 oxygen problem. ONE CHINESE GUY HAD JUST BEAT THE ENTIRE LOCKHEED ENGINEERING TEAM in 3 minutes.

Well it was the upper pressure vest relief valve failing to release, and I do believe you may have been partially right about them pushing to much oxygen, that may contribute to the Raptor cough? JamieLi, you're only problem is you're just too modest dude. Maybe you could offer your services back on the mainland, maybe they'll hire you at Shenyang? Cheers Brat

 

[gf0012-aust]

Sorry folks. Closed pending review - and if anyone thinks they have a compelling reason to get this unlocked then PM any Mod and we'll discuss

my patience has run out when I see someone stating that they're not an arrogant man and then capitalising their comments

find another forum if you want to brag about your expertise.

there are ways to engage, and there are clear ways to write yourself off due to an inability to behave properly

 

[Bonza]

Hope you enjoyed your time with us, James. Thankyou for sharing your wisdom on the F-22. Make sure you don't come back. Cheers.