Apparently, Air Force accident investigators weren't even aware that there was a flight data recorder aboard the CV-22 that crashed in Afghanistan last April. This pretty big accidental oversight may be partially to blame for the conflicting reports that the crash may or may not have been caused by a combination of engine power loss and pilot error.
While Air Force's lead investigator into the crash, now-retired Brig. Gen. Donald Harvel, said in the summary of his accident investigation that he belied the cause of the crash could well have been engine trouble, the Air Force nixed this as an official cause of the crash, in part because the Flight Information Recorder was destroyed.
However, Harvel tells Steve Trimble that no one was able to review the information from the aircraft's Flight Incident Recorder because it was never looked for.
Several rescue and salvage crews failed to grab the critical device because the incident recorder was not among the items listed for recovery at the crash site, according to Harvel. This was apparently due to a translation problem between U.S. Marine Corps and U.S. Air Force manuals for the V-22.
AFSOC inherited instructional manuals - called "Dash-1s" - for the CV-22 from the Marine Corps' MV-22B units. It was necessary to translate the manuals from Marine piloting and maintenance jargon to USAF terminology, but the translators made a few mistakes, Harvel says.While the aircraft was destroyed with a bomb right after the survivors were rescued, the data recorder was designed to survive such a blast.
"Somehow in that translation there was nothing in [the AFSOC manual] that showed this aircraft had a FIR," he says. "They had absolutely no idea."
As a result, he adds, the FIR "was never on the list to get that off the airplane" after a crash.
However, the Air Force's statement on the matter said the recorder was destroyed, preventing a complete examination of the incident. It doesn't say how it was FIR destroyed.
Yet Trimble's article goes on to say that, a day after the crash, an Army team went to the site to document it and retrieve more sensitive gear. The team took a picture of what might have been the recorder and then left the site with the intention of recovering more items the next day. When they went back however, the device was gone. Sounds like someone other than the U.S. military now has the black box.
This means it's all the more difficult to definitively say what caused the first ever combat loss of a V-22.
The absence of the FIR means several theories about the cause of the CV-22 crash are possible, he says.
"I could understand how there could be people looking at the same evidence and come to different conclusions," Harvel says.For something important like this, shouldn't we focus on standardizing as much information as possible. I know services have their own traditions. That's fine. But why can't U.S. flight manuals feature as much common language as possible; only using distinct terms when discussing parts that are unique to an individual service's version of an aircraft?
Here's his article.