F22 fleet grounded

[sr01]

http://www.airforcetimes.com/news/2011/ ... t-050511w/

[james84]

Interesting. I would like to see what happens in the case of a similar occurrance with the F-35... several countries would have no defence at all!

[sprocky]

"Grounded"? I think it was flightglobal where I read about a stand-down not a grounding. They explained that grounding would be if an aircraft type had something serious related to the controls or engines. In this case they could still fly at lower levels

[james84]

Iread somewhere that the 4 Hawaii ANG Raptors are not flying, and the patrol duties have been temporariliy taken over by some Montana ANG F-15s.

[Firebird]

Well if it's anything like my time in the RAF the fleet would still be WG anyway, War Go-er.

For example we would have the F-4s as WG with only one engine working, no ejector seats, or no radar. This would be a peacetime restriction so it's not quite as bad as it seems. Pilot currency would be the only issue, but that is what sims are for.

[hawk_sh]

I am somewhat surprised that the Raptors are still grounded...

http://www.airshowbuzz.com/cms/244689/a ... _fly_again

[reconmercs]

eh, maybe its time for a QF-22 program instead of the QF-16...outside of flying a cool airshow and being in a couple movies this thing has been nothing more than a maintenance nightmare since it reached IOC here's hoping the F-35 isn't Raptor part deux....

[Firebird]

Roll up, Roll up get yer brand new Typhoons 'ere. We will even let you build them if you ask nicely.

[Keith Jones]

Roll up, Roll up get yer brand new Typhoons 'ere. We will even let you build them if you ask nicely.

[MIKE JG]

Thought it had something to do with the onboard O2 generation system?? Something about the system that takes ozone fron the atmospere and converts it into breathable O2 for the pilot.

[Victory103]

It does, the Navy had the same issue with their OBOGS and fixed it, guess the AF doesn't want to ask them for help. T-38's should be arriving at Tyndall and Langley soon so the Raptor drivers will have something to fly.

[hawk_sh]

T-38's should be arriving at Tyndall and Langley soon so the Raptor drivers will have something to fly.

Are these the T-38s planned for adversary duties or do they relocate extra aircraft?

[reconmercs]

T-38's should be arriving at Tyndall and Langley soon so the Raptor drivers will have something to fly.

Are these the T-38s planned for adversary duties or do they relocate extra aircraft?

They are supposed provide local adversary duties, a couple had already arrived at Langley when I was up at the airshow a couple months back, don't know how many they're supposed to end up getting though

[Victory103]

I believe also to fill currency requirements much like the HO T-38's did.

[Greg]

Roll up, Roll up get yer brand new Typhoons 'ere. We will even let you build them if you ask nicely.

Keep your Typhoons, all we had was trouble with them at Koksijde Air Show.

Both the Italian and German Typhoons were leaking fuel like crazy because for some reason our standard, NATO qualified GPU's aren't compatible with this aircraft and the pilots couldn't vent their fuel tanks or they wouldn't have enough power left for start-up. A few hours in the blazing sun and you can imagine how much pressure there must have been in those tanks.

At some point, there was so much kero leaking on the static line that it was creating a pool around the landing gear before the fire crew could get there. And because kero and rubber don't go well together, the pilot was afraid he would blow his tire on take-off.

The pilots were complaining that they have this problem at most airshows.

[MIKE JG]

An update: http://www.airforcetimes.com/news/2011/ ... ng-072111/

The prolonged grounding of the Air Force’s F-22 Raptor fleet may be due to carbon monoxide entering the cockpit via the aircraft’s oxygen system, two sources said.

Service leaders grounded the stealthy twin-engine fighter May 3, after 14 incidents when F-22 pilots suffered “hypoxia-like symptoms.”

Air Force officials initially suspected a problem with the aircraft’s On-Board Oxygen Generation System (OBOGS), but that is looking less likely, the sources said.

Instead, investigators now suspect that carbon monoxide generated by the plane’s jet engines is getting into the cockpit.

Part of the problem may be the procedures used at Elmendorf Air Force Base, Alaska, where most of the known incidents have occurred. Because of the harsh climate, pilots often start their jet engines inside a hangar before taking off. Investigators suspect that exhaust gases are getting trapped in the building and subsequently sucked back into the engines, where they enter the bleed air intakes that supply the OBOGS, sources said.

The design and placement of the intakes, which are located within the engines’ compressor sections, are fairly standard for jet aircraft.

There is no immediate fix in sight, sources said.

Asked for comment, an Air Force spokesman said he had no further information at this time.

“The safety of our aircrews is paramount, and the Air Force continues to carefully study all factors of F-22 flight safety,” said Maj. Chad Steffey.

One aviation safety expert said that if the hypoxia is being caused by carbon monoxide in the cockpit, the gas is likely being generated by the plane’s engines.

“I would think that it has something to do with exhaust flow somehow getting into the oxygen generating system,” said Hans Weber, who sat on the U.S. Federal Aviation Administration’s Research, Engineering and Development Advisory Committee, and is president of Tecop International, a San Diego consulting firm.

Even a small amount of the colorless, odorless gas can have serious effects, Weber said.

“It doesn’t take a large concentration of carbon monoxide to start affecting people, making them ill — and not just ill but really diminishing their ability to perceive anything.”

Weber said the difficulty of the fix will depend on the problem.

If the carbon monoxide is being ingested because the engines are being started in confined spaces, a fix could be as simple as moving the jet outside, Weber said. If the engine must be started inside the hangar, the startup of the oxygen system might be delayed until the jet is out in the open, he said.

But if dangerous levels of carbon monoxide are entering the cockpit despite these changes, the Air Force might have to add bulky cartridges or scrubbers to the life-support system, he said.

The Navy has had similar problems with the OBOGS on its F/A-18 Hornet, which sucked carbon monoxide into its oxygen system during carrier operations.

Between 2002 and 2009, Hornet aviators suffered 64 reported episodes of hypoxia, including two that killed the pilots, according to the July-August 2010 issue of “Approach,” a Navy Safety Center publication.

Some 77 percent of the incidents happened in single-seat Hornets, which saw 3.2 incidents per 100,000 flight hours. The two-seat version saw 1.7 incidents per 100,000 flight hours.

According to Navy documents, “Prolonged exposure to jet engine exhaust while sitting behind another aircraft waiting to take off and operating with low bleed air pressures can result in carbon monoxide (CO) breaking through … into the pilot’s breathing gas.”

The Navy modified the planes’ OBOGS to fix the problem, has had no recent similar incidents, and is not currently investigating the systems, Naval Air Systems Command officials said.

Interesting..... I hope it's not as simple as not starting the jets indoors.... Don't get me wrong but I can't see professionals overlooking such a thing.