What happened
On 9 September 2010, a Piper PA-22-150 aircraft, registration G-ARHN, was conducting a private flight from Popham to Bembridge. Approximately 15 minutes into the flight, while cruising at 1,800 ft, the pilot experienced a sudden engine power loss accompanied by a bang and sputtering noise. Unable to maintain altitude, the pilot attempted a forced landing in a nearby field.
During the approach, the aircraft lacked sufficient energy to reach the intended landing area. The aircraft struck the roof of a house in Woodlands, Hampshire, before continuing its descent into a garden, where it destroyed a greenhouse. The impact resulted in two serious injuries, affecting both the pilot and the passenger. No injuries were reported to anyone on the ground.
The investigation
The AAIB investigation focused on the engine, fuel, and ignition systems to determine the cause of the power loss. Examination of the engine revealed that the carburettor had been damaged, but subsequent testing showed the engine could run normally. The magnetos were also inspected; although the external labels suggested they had not been overhauled since 199 and the wiring showed signs of fraying, bench tests confirmed they were functioning correctly.
Regarding the fuel system, the investigation found that the left tank contained 45 litres of uncontaminated Avgas, while the right tank was empty. Although the fuel selector was found in the right-tank position, investigators noted that the right tank's fuel could have drained away due to a broken fuel strainer caused by the impact. The investigation could not establish a definitive cause for the engine failure.
Findings
- The engine failure had no established cause.
- The pilot's flight path angle was steeper than a typical practice forced landing, which likely contributed to the inability to reach the selected field.
- The aircraft's flight path required crossing a residential street to reach the landing site, increasing the risk of collision with structures.
- The engine's magneto 'P' leads were in poor condition with frayed and broken insulation, though this was not considered the primary cause of the failure.