What happened
On April 22, 2001, a private Mooney M20E aircraft, registration N200YS, departed Brive, France, on an instrument flight rules (IFR) flight bound for Augsburg, Germany. The pilot was accompanied by two passengers. Shortly after takeoff, the pilot notified the airfield traffic service (AFIS) of smoke inside the cabin. After performing a low pass with the landing gear extended, the pilot reported that the smoke had cleared and continued the flight.
While climbing through 3,000 feet, the pilot contacted Bordeaux Control to receive updated instructions. At 14:14, the controller requested confirmation of the aircraft's altitude; the pilot responded that he was descending to 12,000 feet. This was the final communication from the crew. Shortly before 14:17, radar contact was lost. The aircraft subsequently struck trees at the top of a hill and collided with the ground at a high speed in a steep dive near a residential area. Witnesses reported seeing the aircraft perform a vertical loop before the impact.
The investigation
Investigators examined the wreckage and determined that the engine was producing power at the time of impact, as evidenced by the deformation of the propeller and spinner. Forensic examinations of the three occupants revealed that all died due to carbon monoxide poisoning.
Technical analysis of the cabin heating system, including the heat exchanger and piping fragments, confirmed that exhaust gases had entered the cabin. Specifically, volatile lead bromide from the combustion gases was detected on the internal surfaces of the heat exchanger and the cabin floor. While the exhaust system was too damaged by the crash to be fully reconstructed, no evidence of corrosion or cracks was found in the remaining metal components.
Evidence also emerged regarding the aircraft's recent history. On the day prior to the accident, the same passengers had traveled in the aircraft from Augsburg to Clermont-Ferrand, where the pilot reported feeling headaches due to exhaust odors. On the morning of the accident, the pilot experienced similar odors during a flight from Clermont-Ferrand to Brive. In both instances, the pilot attempted to manage the issue by adjusting the heating and ventilation settings.
Findings
- The primary cause of the accident was the inhalation of toxic exhaust gases within the cabin.
- Carbon monoxide entered the cockpit through the heating system, leading to pilot incapacitation.
- The pilot failed to adequately address the underlying exhaust leak, attempting instead to manage the symptoms by adjusting ventilation.
- The engine had operated for 1,080 hours since its last overhaul.