The service's explanation that the numerous cases of oxygen deprivation suffered by Raptor pilots were due to improper use of the gravity suits worn by the pilots rang particularly hollow for one member of the House Armed Services Committee.
"The jury is still out on this fix," Speier told The Hill shortly after the hearing, adding she thought the Air Force was rushing to "put something to bed" at the risk of endangering airmen.
That said, a handful of committee members are considering making a visit to Langley Air Force base, to get more information on Raptor flight operations from F-22 pilots stationed there.
Thursday's hearing was the first time Air Force brass had come to Capitol Hill to explain why the F-22 was causing such damage to service pilots and what the service has done to mitigate that risk.
From April 2008 to May 2010, 14 "psychological incidents" occurred among Air Force pilots flying the F-22. Ranging from severe bouts of dizziness to pilots blacking out, the incidents prompted the Air Force to temporarily ground the entire Raptor fleet twice last year.
Initially, service officials indicated the problems may have been rooted in the deficiencies within the plane's oxygen delivery system. Later, Air Force leaders linked the cause of the incidents to misuse of the gravity suits worn by Raptor pilots.
"Oxygen contamination was ruled out as a potential cause," subpanel Chairman Rep. Roscoe Bartlett (R-Md.) said during the hearing.
When flying under high G-forces, the suits are designed to inflate and provide pressure on the pilot's body. That pressure keeps blood from draining from the pilot's brain when flying under those conditions.
However, premature or incorrect inflation of those suits can constrict breathing and lead to symptoms of oxygen deprivation.
"Systemic factors in the life-support system, such as the combat edge upper pressure garment ... have been identified, removed, and corrective action is under way," Director of Operations at Air Combat Command Maj. Gen. Charles Lyon, who led the investigation into the Raptor flight incidents, told the subcommittee on Thursday.
The Air Force F-22 fleet has not suffered any similar incidents since March 8, according to Lyon.
"Since that time, we've flown more than 10,000 sorties, totaling over 13,000 hours, without incident," the two-star general said. "That trend is on a positive vector not seen in years."
While flaws in the oxygen system were ruled out, the Air Force is also planning on revamping the entire life support system — including the oxygen system — aboard the Raptor, retired Air Force Gen. Greg Martin, who led the Air Force Scientific Advisory Board inquiry into the incidents, said during the same hearing.
Those life system upgrades will be in place by the end of this year, Martin told subcommittee members.
While Bartlett and other members seemed satisfied with the Air Force response, Speier pressed service officials on the possibility of the long-term effects of the incidents that led to Thursday's hearing.
Blackouts, loss of memory and vertigo, along with the so-called "Raptor cough" were common symptoms suffered by service pilots long after they suffered the psychological incidents aboard the F-22, Speier said during the hearing.
Speier said these lingering questions, among others, are the main reason for her suspicion regarding the Air Force's explanation and subsequent remedies to the F-22 problem.
The Air Force was "pushing the envelope" to get the Raptors flying as soon as possible, she said. "We have to be ... clear," Speier said. "They're pushing the envelope with the lives of [American] servicemen."