What happened
The pilot and two passengers were returning from a hunting trip when the aircraft crashed approximately seven miles from Fairbanks International Airport. The airplane struck the ground in a vertical attitude at a high rate of speed.
The investigation
Evidence at the crash scene suggested that the left wheel penetration ski had deflected inflight just prior to the impact. Other pilots who have experienced similar problems with this type of ski report that the deflection is accompanied by a violent pitch down of the airplane.
The pilot had not complied with an FAA airworthiness directive dated May 12, 1980, which required the skis be modified to preclude such occurrences. Additionally, the pilot had knowledge of, and failed to remove, three tent poles that had fallen behind the aft baggage compartment. One of these poles and the elevator bellcrank assembly showed signs of interference that indicated control binding.