N4350K

On August 2, 2000, approximately 1020 mountain daylight time, a Kokenge Glastar experimental-category airplane, N4350K, was destroyed in a collision with terrain following takeoff from runway 33 at Bert Mooney Field, Butte, Montana. The private pilot-in-command and his passenger received serious injuries in the accident. Visual meteorological conditions prevailed, and the FAA did not indicate any record of the aircraft filing a flight plan for the 14 CFR 91 personal flight bound for Yakima, Washington.

Witnesses reported that they observed the airplane begin its takeoff roll on runway 33 from taxiway E. They stated that after becoming airborne, the airplane got about 50 to 60 feet in the air, then made a sharp right turn. The witnesses stated that the airplane "[took] a nosedive" or "nosed into the ground" when it made this sharp right turn. The aircraft impacted the ground and came to rest just east of the intersection of runways 15/33 and 11/29. A post-crash fire ensued; however, the aircraft occupants were moved to safety by responding emergency personnel. The pilot reported to the NTSB that he had little recollection of the accident sequence. Investigators did not determine the reason for the sharp right turn and nose drop to ground impact observed by the witnesses. A report by the responding FAA inspector, from the Helena, Montana Flight Standards District Office (FSDO), stated that the aircraft's engine was producing power at impact.

According to one witness, an airport weather observer who had just taken an hourly observation, the weather conditions at the time of the accident were: temperature 79 degrees F, winds variable at 5 knots, few clouds at 10,000 feet, few clouds at 15,000 feet, and visibility 25 statute miles with haze. Based on a pressure altitude equal to Mooney Field's elevation of 5,545 feet above sea level and temperature of 79 degrees F, density altitude at the time was computed to be approximately 8,000 feet.

According to U.S. Government flight information publications, runway 33 is a 9,000 foot long by 150 foot wide grooved asphalt runway. Approximately 7,070 feet are available for an intersection takeoff from taxiway E.