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| Science & Technology |
| All F-22 Raptors Have Been Grounded Since Early May |
| 2011-06-26 |
| Several pilots have reported problems with their oxygen supply, and some near crashes have resulted blamed on hypoxia. Since January, Raptors have been prohibited from flying higher than 25,000 feet since a training accident in Alaska. The Air Force has more than 160 F-22 Raptors in its fleet and plans to build a total of 187. In 2007-2008 all F-15 fighters were grounded for four months after one aircraft fell apart in flight. |
| Posted by:Anonymoose |
| #2 I agree with one of the comments for this post. Work was perhaps subcontracted out. A glitch in a very sophisticated craft. The molecular sieve material perhaps is needing replaced. It doesn't last forever. As it degrades the purity of oxygen diminishes- Slowly. Should have had some sort of alarm to alert pilot. Yes "It will be interesting to see what the investigation reveals" but we may never know. |
| Posted by: Dale 2011-06-26 22:50 |
| #1 Unlike legacy systems, OBOGS (On Board Oxygen Generating System) takes the outside air and runs it through a membrane that separates the oxyen molecules from the nitrogen and dumps the N2 over the side. In theory a simple and reliable system that is in use in many military aircraft. It will be interesting to see what the investigation reveals. It's sister system, OBIGGS, does the same thing, but retains the N2 for fuel cell inerting and dumps the oxygen. And yes, the various ports and fittings between the two elements ( N2 and O2) are different sizes to reduce potential 'Murphys.' |
| Posted by: USN,Ret. 2011-06-26 18:44 |