What happened
Following departure, the pilot was cleared to climb to 9000 feet. During the final portion of this climb, the rate of climb began to decrease. Upon reaching 8000 feet, the aircraft entered a descent to 4100 feet, followed by a subsequent climb to 5100 feet. The aircraft then entered another descent and leveled off at 3800 feet, at which point it disappeared from radar. The aircraft subsequently descended and crashed in mountainous terrain.
The investigation
Witnesses at the scene reported that the engine was operating at a high power setting prior to impact. The investigation found no preimpact part failure or malfunction. However, icing conditions were present in the area; an MD-80 and a Beech 99 had both reported encountering moderate rime icing. Additionally, the pilot had previously noted encountering ice during a flight to Rochester.