ever since captain jeffrey haney lost consciousness and crashed his f-22 into an alaskan mountainsider force and lockheed martin engineers have struggled to find the cause. the air force grounded the f-22 for four months last year, but since the raptors returned to flight in september, 11 pilots and five maintainers have complain -- complained of hypooxy restrictions. rebecca grant is the president of iz ris independent research which advises the air force, navy and other agencies and contractors, including f-22 maker lockheed martin. rebecca, welcome back. >> thank you, vago. nice to be here. >> why did secretary panetta do what he did, how unusual was his involvement in the program and when do we expect this all to be lifted? >> secretary panetta obviously wasn't satisfied with what he was saying. i think he has a big heart, he was concerned about the human element, what's really going on with the pilots who fly the f- 22, why are they standing up and saying that they're worried about being in this aircraft. and it's very unusual. i can't remember, vago, maybe you can, a time when w

. >> reporter: two years ago, captain jeffrey haney was killed when his oxygen was cut off and his f-22 crashed in alaska. but to the outrage of his family, the air force blamed him, not its expensive aircraft. >> he gave his life and he just deserves the truth. >> reporter: this computer simulation prepared by the air force shows what happened to captain haney. >> the beeps going off are telling the pilot, something's gone wrong with the airplane. >> reporter: former navy pilot steve ganyard, an abc news consultant, says the intrumt shows that he blacked out and the gaining con shssness too late. for the lockheed martin company, and in a ceremony today the final of some 187 f-22's was turned over to the air force. >> we complete the f-22's fifth generation, flight or fleet. >> reporter: but for now, the prominent use is to perform tricks in air shows, a $500 million stunt claim. the fleet was grounded last year for five months and they could not fix the oxygen problem. as you will see on "nightline," the air force says it has added safety features for a flean they are calling a turke

. >> reporter: two years ago, captain jeffrey haney was killed when his oxygen was cut off and his f-. but to the outrage of his family, the air force blamed him, not its expensive aircraft. >> he gave his life, and he just deserves the truth. >> reporter: this computer simulation, prepared by the air force, shows what happened to captain haney. >> the beeps going off are telling the pilot something is going wrong with the airplane. >> reporter: an abc news consultant said the instruments seemed to show that haney blacked out for at least 15 seconds and regained consciousness too late to save the plane. the f-22 has meant huge profits for the lockheed martin company. and in a ceremony, the final of some 187 f-22s was turned over to the air force. >> we complete the nation's f-22 fifth generation fighter fleet. >> reporter: but for now, however, the f-22's most prominent use seems to be to perform tricks in air shows. in effect, a $500 million stunt plane. the air force says some of the f-22s have now been deployed to the middle east as a show of force to iran and that it has added new