Incident
On approach to Lewiston Airport, Idaho, the pilot encountered poor weather conditions and decided to divert to Pullman-Moscow Airport. The alternate airport was also closed to traffic due to poor weather. While on approach in snowfall, the pilot did not recognize that his altitude was insufficient, and the aircraft struck a ridge located approximately half a mile north of the airport. The aircraft was destroyed, and the pilot, the sole occupant, was killed.
Probable Cause and Contributing Factors
The investigation determined the probable cause to be a controlled collision with the ground on final approach due to improper IFR operation. Numerous contributing factors were reported. The weather conditions included a low ceiling, snow, and visibility of half a mile or less, which were below the minimums for the approach. The runway at Pullman-Moscow was closed, as indicated by a NOTAM that prohibited landings because of plowing. However, the controller did not have the NOTAM and therefore failed to advise the pilot of the unsafe airport conditions. ATC personnel also did not advise the pilot of the dangerous situation. Additionally, plows were present on the runway at the time of the accident.