What happened
On 23 July 2008, a Piper PA-38-112 Tomahawk, registration G-RVRG, was being used for an introductory flight at Barton Aerodrome (City Airport Manchester). During the takeoff roll on the grass Runway 09R, the aircraft unintentionally became airborne after passing over a known hump in the runway surface.
Although the aircraft initially reached an airspeed of 53 kt, it failed to accelerate and climb effectively. The pilot, attempting to maintain control and ensure sufficient performance to clear nearby obstacles such as houses and a viaduct, attempted to raise the nose. However, as the aircraft approached the aerodrome boundary at approximately 50 feet, it lost height and the right wing dropped. The pilot initiated a forced landing in an area of open ground between the boundary fence and nearby houses. During the maneuver, the aircraft entered a stall and impacted the ground nose-first. The pilot sustained serious injuries, while the passenger escaped without significant physical harm. The aircraft was destroyed.
The investigation
The AAIB investigation examined the wreckage, which was located in a hollow of scrubland. The aircraft's longitudinal axis was found significantly offset from its original direction of travel, with the right wing tip having impacted the ground first.
Technical inspections of the Piper PA-38-112 revealed that the engine, which had been recently replaced, was in normal operating condition. Borescope inspections of the cylinders and valves showed no defects. Fuel samples taken from both tanks were found to be free of contamination. The investigation also confirmed that the aircraft was within weight and balance limits, with a takeoff weight of 1,658 lb. The investigation noted that while the fuel selector valve initially appeared to be in the 'off' position, this was likely due to displacement during the impact.
Findings
- The aircraft became airborne at its stall speed due to the runway surface undulations.
- The aircraft failed to achieve sufficient takeoff speed before becoming airborne.
- At the stall speed, there was no performance margin, making the aircraft highly susceptible to a stall following any change in flight path or control input.
- The aircraft was in an airworthy condition and operating normally immediately prior to the accident.