The outside air was cold enough to cause water dissolved in the Pilatus PC-12/45’s Jet-A fuel to form ice crystals that accumulated on the main fuel filter and built up sufficiently on components in the left wing tanks to block the flow of fuel from the tanks. The airplane became increasingly left-wing-heavy as excess fuel returned by the engine was added to the fuel trapped in the left tanks while the right tanks continued feeding the engine.
The pilot pressed ahead toward the planned destination until he apparently realized that his efforts to balance the fuel and to correct the low-fuel-pressure condition were not working. He diverted the flight to an alternate airport but lost control of the airplane while maneuvering to land. The PC-12 crashed near the runway, killing all 14 people aboard.
In its final report on the March 22, 2009, accident, the U.S. National Transportation Safety Board (NTSB) said that the probable causes were “the pilot’s failure to ensure that a fuel sy…
