The National Transportation Safety Board has published the official "probable cause" of the 2007 accident that cost wealthy adventurer Steve Fossett his life. It was "the pilot's inadvertent encounter with downdrafts that exceeded the climb capability of the airplane [in combination with] mountainous terrain."
It sounds as if it were an act of God: Poor Fossett was flying along and suddenly a rogue wind grabbed him and slammed him into a mountain. But it was almost certainly more complicated than that.
The NTSB's conclusion in the Fossett investigation was not based on a lot of highly scientific CSI-style analysis. Some NTSB accident investigations are. But in this case, there was almost nothing to analyze. The airplane was so badly pulverized that searchers flew over it without noticing the debris. Meteorologists knew that there was a moderate southwest wind over the mountains at the time of the accident, but their computers could not tell them what the air was doing at any particular location. Reports from several pilots, and from a camper who probably saw Fossett clawing his way southward against a strong head wind minutes before the crash, painted inconclusive, even contradictory, pictures of conditions that day. The coroner had nothing to work with but a couple of bones.
On the other hand, when an airplane slams into a mountain and the "damage signatures" on the propeller blades prove that the engine was delivering power on impact, the NTSB does not have a lot of causes to choose from. The diagnosis pretty much has to be turbulence, pilot error, pilot incapacitation or suicide.
The board has not hesitated to ascribe similar accidents to poor preflight planning or faulty in-flight decision-making or to failure to remain clear of terrain -- all somewhat circular verbal formulas that boil down to "failure to avoid the accident." When faced with a dearth of material evidence, the board even sometimes resorts to "for unknown reasons."
In this well-publicized case, however, "unknown reasons" might have looked incompetent, there was no evidence to support incapacitation or suicide, and "pilot error" would have been controversial and even offensive to the victim's many admirers. And so the board invoked "downdrafts."
But pilots know there had to have been more to the story. One fundamental rule of flying is: Always have a way out. A cautious pilot would have weighed the likelihood of unpredictable turbulence against the limited capabilities of his plane in the thin air and would have kept a good deal of space between himself and the rocks.
