Bozeman

On March 22, 2009, about 1432 mountain daylight time, a Pilatus PC-12/45, N128CM, was diverting to Bert Mooney Airport (BTM), Butte, Montana, when it crashed about 2,100 feet west of runway 33 at BTM. The pilot and the 13 airplane passengers were fatally injured, and the airplane was substantially damaged by impact forces and a post crash fire. The airplane was owned by Eagle Cap Leasing of Enterprise, Oregon, and was operating as a personal flight under the provisions of 14 Code of Federal Regulations Part 91. The flight departed Oroville Municipal Airport, Oroville, California, on an instrument flight rules flight plan with a destination of Gallatin Field, Bozeman, Montana. Visual meteorological conditions prevailed at the time of the accident.

The cross-country flight was on an instrument flight rules (IFR) flight plan, approximately 42 nautical miles from the tower-controlled destination airport, when the pilot was cleared for the visual approach. Dark night visual meteorological conditions prevailed, and there was an overcast layer of clouds at 11,000 feet. After the en route radar service was terminated, the pilot contacted the local control tower and made a garbled and partially unintelligible transmission. Shortly after the time of the transmission, local law enforcement personnel received reports of a downed aircraft. The wreckage was located later that evening approximately 80 feet below the peak of a ridge that rose to an elevation of approximately 5,700 feet. From the initial point of contact with terrain, the debris path was scattered over the crest of the ridge and continued down the opposing side, in a south-southeast direction, toward the airport. The ridge was the highest obstruction between the accident location and the destination airport. The airport is located in a large valley and is surrounded by rising mountainous terrain. At night, clouds and terrain are difficult for pilots to see, and a gradual loss of visual cues can occur as flight is continued toward darker terrain. Additionally, the horizon is less visible and less distinct at night than during the day. Because the pilot was descending the airplane over rural, mountainous terrain that provided few visual ground reference cues, and because the overcast cloud layer would have prevented moonlight from illuminating the terrain, it is likely that the pilot did not see the rising terrain as the airplane continued toward it. The airplane was equipped with an Enhanced Ground Proximity Warning System; however, impact damage to the unit precluded post accident testing. It is not known how the unit was configured during the flight or what type of alerts the pilot received prior to impact. Post accident examination of the wreckage, to include both engines, did not disclose evidence of a mechanical malfunction prior to impact. Additionally, no evidence was found to suggest an in-flight structural failure.

The airplane was on the final approach segment of an instrument flight rules (IFR) cross country flight that originated approximately 3 hours and 45 minutes prior to the accident when radio communications with the aircraft were lost. The aircraft wreckage was located the following day approximately 2.8 miles from the destination airport. The airplane impacted terrain in a vertical descent and flat attitude and came to rest upright on its fuselage and wings. The cockpit and cabin were intact and both wing assemblies remained attached to the fuselage. Evidence of forward velocity and/or leading edge deformation was not observed to the wings or fuselage. Mixed ice was noted along the leading edge of both wings. At the time of the accident, weather conditions were reported as low ceilings and low visibility due to snow and mist. The accident occurred during dark night conditions. Air traffic control (ATC) transcripts indicated that shortly after entering the holding pattern at 11,000 feet the pilot was issued an approach clearance for the ILS. The pilot acknowledged the clearance and approximately two minutes later ATC communications with the pilot were lost. Pilot logbook records showed that the pilot's total flight time was approximately 1,987 hours. In the six-month period preceding the accident, the pilot logged approximately 40 hours total time, 9 hours of actual instrument time and 7 instrument approaches in the accident airplane. The pilot's total night flying experience was approximately 51 hours. The pilot made no entries in his pilot logbook indicating that he had flown at night in the six-month time frame preceding the accident. Pilots flying the ILS approach prior to the accident aircraft reported mixed icing during the descent and final approach. Post accident examination of the aircraft revealed no evidence to indicate a mechanical malfunction or failure.

While cruising at an altitude of 9,000 feet in good weather conditions, the twin engine aircraft went out of control, entered a dive and crashed on a wooded hill located some 22 km northeast of Bozeman. All 10 occupants were killed.
Crew:
Nick B. Mamer, pilot,
Frederick W. West, Jr., copilot.
Passengers:
T. Anderson,
I. E. Stevenson,
G. A. Anderson,
L. Levin,
Walter Ton,
A. Croonquist,
Douglas McKay,
W. E. Borgenheimer.