Earlier in the day and prior to the accident flight, the pilot flew uneventfully from Havre City Airport (HVR), Havre, Montana to GDV. The airplane was fueled before departing HVR, and again after arriving at GDV. The pilot then departed on the accident flight at 1843, for STP.
According to preliminary communication and radar data provided by the Federal Aviation Administration (FAA), all communications were normal until the pilot advised air traffic control (ATC) at 1911, that he saw a contrail coming from his airplane, and that "he had never seen that before." At 1934, the pilot advised ATC that he was having communications problems, and at 1937, he was cleared to climb to flight level 270. The pilot did acknowledge the instruction, and no further transmissions were received from him.
At 2032, ATC became concerned because the airplane was approaching its destination, and no request to descend had been received from the pilot. Multiple attempts to make contact with the pilot by ATC were unsuccessful, and the airplane's reported altitude began to fluctuate, at times indicating that the airplane was 300 feet higher than the assigned altitude. At 2040 the airplane over flew St. Paul Minnesota and assistance was requested from the North American Aerospace Defense Command (NORAD).
At 2049, fighter aircraft were "scrambled" to intercept the accident airplane. The fighters visually acquired the airplane at 2114, and after closing with the airplane, attempted to look into the cockpit. The pilots described that they observed either glare from the setting sun or frost on the windows. An attempt to gain the pilot's attention by firing flares and doing a flyby with their afterburners on was unsuccessful.
At 2146, two more fighters were "scrambled" by NORAD to relieve the original intercepting flight, which was running low on fuel. The replacement fighters began tracking the airplane at 2204, and also attempted to gain the pilot's attention by firing flares. The pilots noted that in the darkness, they could see that the airplane's interior lights were on, but could not see the pilot or discern any movement in the cockpit. About 2231, the airplane began to descend, and at 2234 the airplane was lost from radar.
Witnesses that lived adjacent to the accident site reported that about 2250, they heard a "boom," similar to "a bomb" exploding outside of their residence. After stepping outside they observed two fighter airplanes pass overhead. A short time later, an emergency medical service helicopter circled their house, landed, and departed again.
At approximately 2319 they discovered the wreckage of the airplane on a hill behind their residence.
The accident occurred during the hours of night. The wreckage was located at 38 degrees, 30.792 minutes north latitude, 81 degrees, 53.933 minutes west longitude.
Examination of the cockpit revealed that the vertical speed indicator needle was lodged in the -4,400 foot per minute position. The autopilot and trim switches were in the on position. The heater switches were on. The throttle controls, propeller controls and mixture controls were in approximately the midrange position. The flap indicator and flap switch lever were in the flaps up position. The landing gear selector switch was in the gear up position. The left and right fuel selectors were set to "on." The pilot's seat belt and shoulder harness assemblies were found intact and latched. The cabin door latch assemblies and baggage door assemblies were found in the closed and locked position, and exhibited witness marks at the latch pins.
The pilot was found strapped into the left front seat of the airplane wearing an oxygen mask. A pulse oximeter was discovered laying on the ground 6 feet outboard of the left wingtip. In addition to the installed oxygen system on the airplane, a portable oxygen system was found during the wreckage examination. A nasal cannula was connected to the airplane's oxygen system and was found lying on the seat next to the pilot. The mask that the pilot was wearing was found connected to the portable bottle. The regulator valves of both systems were open about halfway, and both were depleted of their contents.
Courtesy of the NTSB NYC06FA079
