The U.S. Air Force unfairly blamed one of its top pilots for the crash that killed him, according to the Pentagon's in-house watchdog, rather than the malfunctioning oxygen systems on his stealth jet.

On Nov. 10, 2010, an Air Force F-22 Raptor stealth fighter piloted by Capt. Jeffrey Haney plunged into the ground in Alaska. Haney died instantly. The Air Force's official Accident Investigation Board (AIB) investigation (.pdf) a year later accused the young pilot of losing control of his $377 million F-22. But it also admitted that the breathable-air system on Haney's jet malfunctioned, with possible effects including oxygen deprivation, impaired judgment and even unconsciousness – symptoms collectively known as "hypoxia."

On Monday, the Defense Department Inspector General called out the Air Force for blaming Haney. The Air Force, it said, pointed a finger at the deceased pilot without adequate evidence and without fully taking into account the possible effects of the failed oxygen gear – problems with which have been found to affect all 180 or so Raptors going back years. "The AIB Statement of Opinion regarding the cause of the mishap was not supported by the facts," the inspector general states in its official report. (.pdf)

The Pentagon's rejection of the Air Force investigation puts the onus back on the flying branch to probe what happened that fatal day over Alaska. At the very least, the Air Force needs to restore the tarnished reputation of a pilot the AIB report itself described as one of the best in his squadron. And if a second probe of the F-22 crash confirms the flawed oxygen system was to blame, the flying branch must take that into account as it tries to fix the pricey stealth jets.

According to the increasingly discredited AIB, "the cause of [Haney's] mishap was the [mission pilot's] failure to recognize and initiate a timely dive recovery due to channelized attention, breakdown of visual scan and unrecognized spatial disorientation." In other words, Haney got confused and flew his plane into the ground.

The Air Force based this conclusion on a second-by-second reconstruction of Haney's final minutes, based largely on data from the wrecked Raptor's black box and analysis of the crash site. The AIB conceded that the F-22's oxygen system malfunctioned and shut down. Following standard procedure, Haney tried to turn on his emergency oxygen, contained in a bottle wedged beside the ejection seat. The Air Force claimed Haney left his oxygen mask on the entire time.

Apparently while fumbling with a tiny green ring that a pilot pulls to start the backup air flow, Haney didn’t notice that his aircraft had rolled over and pointed towards the ground. “It was most likely the [mission pilot] channelized his attention on restoring airflow to his oxygen mask,” the Air Force's report stated.

Three seconds before striking the ground, Haney apparently realized his error and tried to pull up. But it was too late. The F-22 plowed into the snowy earth, digging a deep crater, throwing debris a quarter-mile and killing Haney instantly.

The critical question is whether Haney's cognition was impaired by problems with the oxygen generator in the minutes leading up to the generator's failure and shutdown. If Haney's "channelized" attention and too-late pull-up were consequences of an oxygen-starved brain, then it's not fair to pin the crash on him, the inspector general contends. "The AIB report did not provide a detailed analysis describing why hypoxia was not considered a contributory factor," its report asserts.

What's more, the watchdog office says part of the Air Force's flight reconstruction lack evidence. For one, the inspector insists it's unclear that Haney actually kept his mask on. If he didn't, and instead let the mask dangle so that he could breathe the cockpit's thin ambient air, it could be evidence that Haney was feeling oxygen-deprived even before the oxygen generator's total shutdown.

In other words, the F-22's onboard air system might have started malfunctioning much earlier in the flight, with a possible gradual and pernicious effect on Haney's ability to make sense of his surroundings. That could mean the F-22 killed Haney, not the other way around.

The Pentagon inspector general's report is a powerful blow in Haney's defense against an Air Force eager to protect the tattered fragments of the F-22's once-stellar reputation. But it's not the final word. The Air Force issued a rebuttal to the watchdog office that basically rejects the criticism. "The Air Force found that the AIB President's Statement of Opinion regarding the cause of the mishap was supported by clear and convincing evidence and he exhausted all available investigative leads," the flying branch contends.

The stealth jet blame game isn't over.