What happened
The flight originated from Scottsdale and was en route to Broomfield, Colorado, at Jefferson County Airport. Shortly after takeoff, the pilot encountered instrument meteorological conditions (IMC). The flight continued without incident until the aircraft reached the vicinity of Colorado Springs. At this point, the pilot reported a malfunction with the directional gyro.
In response to the navigation issue and deteriorating weather, the pilot initiated a descent from 19,000 feet to 8,000 feet. This maneuver took place within clouds, under icing conditions, and in snowfall. Approximately twenty-five minutes after beginning the descent, the pilot transmitted a radio message indicating an engine problem, specifically noting that he was "getting a lot of surging." Two minutes later, all radio and radar contact with N6917R was lost.
The flight had originally been destined for Broomfield but diverted to Arapahoe County Airport when the engine issues arose. The aircraft impacted the ground in a right-wing-low, nose-low attitude at a high rate of speed.
The investigation
Examination of the aircraft's engine following the accident revealed no evidence of a mechanical malfunction or failure that would have prevented normal operation. Due to the extensive damage sustained during the impact, investigators could not determine the position of the alternate air door.
The wreckage analysis confirmed the high-speed impact attitude. No mechanical causes were identified that could explain the reported engine surging or the subsequent loss of control.