What happened
On 10 April 2005, a Beech 76 aircraft, registration G-BMJT, departed from Belfast City Airport for a short flight. Shortly after takeoff, following the retraction of the landing gear, the aircraft experienced a noticeable change in engine note, described by witnesses as a reduction in power. The aircraft failed to establish a climb, instead turning left and descending through a line of trees.
After passing through the tree line, the aircraft struck the ground in a nose-down attitude and slid into a boundary hedge. The impact with a steel mesh fence and railings caused a significant post-crash fire. The pilot managed to escape the wreckage unassisted but sustained serious burns. The aircraft was destroyed during the incident.
The investigation
The investigation examined the wreckage, engine components, and propeller mechanisms. Investigators found that the left engine cowl flap was in the closed position and the carburetture heat was set to ON. Evidence from the wreckage indicated that the right propeller was rotating at the time of impact, while the left propeller appeared to have little to no rotation as the aircraft passed through the trees.
Technical analysis of the left propeller revealed a defect in the pitch lock mechanism. Specifically, the piston sleeve had made heavy contact with a cracked pitch lock, which had previously suffered from fatigue. This was likely due to the lock not sliding properly because of corrosion on the retaining bolts. However, investigators concluded that this specific mechanical defect did not cause the power loss observed during the flight.
Findings
- The loss of directional control was most likely caused by a loss of power from one of the engines.
- The pilot was unable to achieve a climb because the power loss occurred at a critical stage of takeoff, immediately after the landing gear had been retracted.
- The aircraft's ability to maintain flight was further compromised because the pilot could not effectively use the engine controls to mitigate the failure.
- The intensity of the post-crash fire was exacerbated by the aircraft's impact with the metal fencing and the subsequent disruption of the airframe.