What happened
On 30 August 2008, a Piper PA-28R-180 Cherokee Arrow, registration G-AVWN, was conducting a private flight from Caernarfon to Jersey. While cruising at flight level 55, the engine experienced a series of surges, followed by a significant reduction in power. The pilot, unable to reach Exeter Airport, requested radar vectors for a precautionary landing and identified a suitable field near the Exe estuary.
As the aircraft approached the chosen landing site, the pilot identified power lines crossing the field. To avoid these cables, the pilot performed a rapid maneuver, lowering the nose to increase airspeed and turning toward an alternative field. This secondary field was intersected by drainage ditches. During the landing, the aircraft struck one of these ditches, causing the landing gear to detach and the aircraft to slide across a second ditch before coming to rest.
All three occupants—the pilot and two passengers—evaculated the aircraft without injury. While the engine did not stop, the impact caused extensive damage to the wings, a bent propeller, and engine shock loading.
The investigation
The investigation examined the engine performance and fuel levels following the incident. Although the pilot had switched to the left fuel tank during a routine check, he later attempted to switch to the right tank during the emergency. Post-flight analysis by a maintenance organization revealed that the right tank was virtually empty, containing less than one litre of fuel, despite no evident leaks.
The pilot also considered whether a malfunction in the propeller control unit might have caused the initial engine surging. However, the investigation focused on the fuel state and the pilot's actions during the emergency.
Findings
- The engine power loss was likely caused by the depletion of fuel in the right tank following the pilot's attempt to switch tanks during the emergency.
- The pilot's decision to switch tanks may have inadvertently caused the engine failure because the right tank was nearly empty.
- The pilot did not monitor the engine or fuel gauges during the emergency, focusing instead on aircraft handling and passenger safety.
- The presence of power lines necessitated a sudden change in landing approach, leading the aircraft into the drainage ditches.