By lex, on December 16th, 2011
Over at the Danger Room, David Axe is making noise ** about the USAF’s official investigation into the loss of an F-22A Raptor and its pilot up in Alaska in November 2010:
When an F-22 Raptor malfunctioned in mid-flight, leading to a crash that killed its pilot, the Air Force went into damage-control mode. Gen. Norton Schwartz, the chief of staff, insisted there was no way that the oxygen generator on his prized stealth jet — a system widely suspected of being dangerously flawed — caused the crash. And even now that an internal inquiry seems to contradict Schwartz, the Air Force is still blaming (the mishap pilot) for the crash that cost (him) his life.
The most important discovery in the Air Force’s official report **on the Nov. 10, 2010 accident in Alaska: The oxygen system in (the) F-22 failed in mid flight. Haney was running out of air. And yet the report concludes the crash was Haney’s fault, not the plane’s.
I plead guilty to actually having followed the link * (pdf), and I think David is off base here. Despite the fact that the OBOGS system onboard the F-22 has proven to be at least potentially responsible for a number of mishaps and near-mishaps, the sequence of events in this particular event indicates a controlled shutdown of the environmental system (ECS) following an engine bleed air warning. The interesting thing about jet engines is that they’re always on fire, but the truly fascinating bit is where the fire is located. A bleed air warning means that fire – or fiercely hot gasses, at any rate – are mucking about where they ought not be. The OBOGS and cabin pressurization system – both necessary to sustain useful O2 uptakes at altitude the mishap pilot was flying – are a part of the associated ECS. They didn’t fail. They were – considering the bleed air warning – purposefully, albeit automatically, shut down.
At OBOGS shutdown, the mishap pilot’s mask was not receiving oxygen. The two choices he had were to activate the emergency oxygen system, and/or remove his mask while doing so. His time of useful consciousness would not have been great with the cabin depressurized, but neither would he have instantly lost consciousness. Contributing factors to the mishap pilot’s failure to activate the EOS were probably his winter weather gear and NVDs, and perhaps the location of the EOS actuation ring.
But any pilot’s first responsibility in extremis is to “maintain aircraft control.” The mishap pilot was coming down from high altitude at a very high rate of descent, and at one point – possibly while straining to activate the EOS – he actually went inverted. At night. In a single-seat fighter. And was sufficiently conscious to execute a sadly delayed dive recovery from an unusual attitude just prior to impact.
I hold no brief for the USAF mishap investigation team, and I’m withholding judgement on the Raptor’s OBOGS implementation. That said, while it’s no doubt tempting to put this particular mishap at the feet of some monstrous military/industrial complex golem, the facts and sequence of events as listed in the mishap report just don’t support that theory.
Sometimes bad things happen.
* 11-06-2018 Link Gone; no replacements found – Ed.
** 11-06-2018 Original link gone; replacement found – Ed.