Synopsis
On 20 February 2009, a DHC-1 Chipmunk 22A, registration G-BWUV, experienced a loss of engine power at an altitude of 300 feet after departing from Runway 29 at Wombleton Airfield, Harome, North Yorkshire. The subsequent forced landing resulted in substantial damage to the aircraft, which was deemed beyond economic repair. The sole pilot, a 59-year-old private pilot with 416 total flying hours (303 on type), sustained minor injuries, while the passenger was uninjured.
History of the Flight
The aircraft had taken off from Runway 29 and climbed to 300 feet when the engine suddenly lost all power. The pilot immediately selected full flap and attempted a forced landing straight ahead. During the landing, the aircraft struck a hedge and a wire fence. The wire fence became entangled with the right undercarriage leg, causing the aircraft to yaw to the right and come to a rapid stop. The aircraft was severely damaged, but the pilot was able to exit normally with only minor injuries.
Investigation Findings
Post-accident examination revealed issues with the magnetos. When the engine was rotated, the left magneto's contact breaker did not open at all, and the right magneto was set to open too far. Consequently, the left magneto was incapable of producing a spark, while the right magneto could only generate a weak and mistimed spark. The pilot reported that the aircraft had flown for approximately 15 minutes without any problems prior to the accident. This suggests that the left magneto setting slipped after the pre-takeoff checks were completed, leaving the engine to run on only the deficient right magneto. This condition may have led to fouled spark plugs, further reducing the engine's power output.