What happened
On 8 July 2007, a Cessna 150L, registration G-HFCI, departed from the Clutton Hill Farm Strip in Bristol. Witnesses observed the aircraft climbing away with an unusually high nose-up attitude and a lower airspeed than typical for such a departure. Shortly after becoming airborne, the engine appeared to lose power, followed by a rapid roll to the left. The aircraft entered a vertical descent, striking the ground approximately 370 metres beyond the end of the runway. The impact was followed by an extensive fire that destroyed the aircraft. Both the pilot and the passenger sustained two fatalities.
The investigation
The AAIB examined the wreckage and the engine components. Investigation of the engine revealed no mechanical defects or failures; the magnetos were found to be functional, and the carburettor and fuel system were clear of obstructions. Analysis of the propeller blades indicated that the engine was not producing significant power at the moment of impact and that the propeller had stopped.
Investigators also recovered plastic containers from the airfield containing a liquid that was chemically similar to the fuel residue found in the aircraft's right tank. While this liquid contained higher concentrations of toluene and other hydrocarbons, laboratory testing on a research engine demonstrated that such a mixture would not have negatively affected engine performance.
Furthermore, the investigation examined the pilot's recent flying history and medical status. The pilot had experienced previous difficulties with navigation and airmanship, which had led to the revocation of solo flying privileges at a training organisation. Post-mortem toxicology revealed the presence of MDMA in the pilot's blood, likely consumed a few hours before the flight.
Findings
- The aircraft entered a fully developed stall during the initial climb.
- The pilot's pitch attitude was so high that the aircraft reached a state of stall even while the engine was still operating.
- The pilot's use of MDMA likely impaired judgement and the ability to perform complex tasks, reducing the ability to operate the aircraft safely.
- The pilot's flying abilities were considered variable and marginal, as evidenced by previous regulatory concerns regarding his airmanship.