What happened
On 23 July 2001, a Fuji FA-200-180AO, registration G-KARY, experienced a loss of engine power shortly after departing from Runway 26 at Tibbenham Airfield. The engine failure occurred at an altitude of approximately 250 feet. In an attempt to restore power, the pilot performed several checks, including adjusting the throttle, magnetos, and mixture, and switching fuel tanks. However, as the aircraft descended to 150 feet without any change in engine performance, the pilot determined that a forced landing was necessary.
Due to the low altitude and airspeed, the pilot was unable to safely execute a turn toward a suitable landing area oriented perpendicular to the flight path. Consequently, the aircraft landed across a field, crossed an unfenced road, and came to a stop in a ditch. The impact was severe enough to dislodge the pilot's spectacles, but the pilot remained uninjured as the four-point harness functioned correctly. The aircraft sustained substantial damage and was deemed beyond economic repair.
The investigation
Investigators examined the circumstances surrounding the fuel system and the aircraft's recent history. While the aircraft was part of a large flying group, it had been stationary for approximately four weeks prior to the accident. During the pre-flight inspection, the pilot had drained the fuel and observed small amounts of water in the starboard tank, though the port tank sample appeared clear. Following this, the aircraft was refuelled and underwent standard power checks, including a tank change.
Upon recovery of the wreckage, investigators observed that the liquid leaking from the engine area onto the tarmac was primarily water, with minor traces of fuel. It was determined that the port tank filler cap was prone to allowing water ingress, and heavy rainfall had occurred during the aircraft's four-week period of inactivity. The pilot noted that a combination of slight colour blindness and an opaque sampling tube may have prevented the detection of pure water in the port tank sample. Because the starboard tank had been sampled first, the scent of fuel on the tube likely masked the presence of water.
Findings
- The engine power loss was caused by water entering the fuel system following a change to the port fuel tank.
- Water had accumulated in the port tank due to a faulty filler cap and recent heavy rainfall while the aircraft was parked.
- The water likely reached the engine only after the initial fuel in the lines was consumed and the tank selector was switched.
- The process of refuelling may have disturbed the fuel-water mixture, facilitating the movement of water toward the engine.
- The pilot's ability to identify the water was hindered by the opacity of the sampling equipment and personal visual limitations.