What happened
On 23 July 2005, a Piper PA-28-181, registration G-BORS, was conducting a private flight from Fowlmere to Oban. After an initial leg of the journey, the pilot landed at Cumbernauld for a break. Prior to departing Cumbernauld, the pilot visually checked the fuel tanks and noted that the right tank contained approximately 65 litres, while the left tank held a lower quantity.
During the departure from Cumbernauld, the pilot performed a tight 180-degree turn and increased power for takeoff. Shortly after leveling off at 3,500 feet while flying south of the P611 Prohibited Area, the engine surged and stopped. The pilot, positioned between Loch Fyne and Loch Awe, immediately initiated a glide toward the shores of Loch Awe. Despite attempts to restart the engine, the power was not restored.
At approximately 1,200 feet, the pilot issued a MAYDAY call and identified a small clearing near the tree line. The aircraft touched down firmly in the grass area, causing the left main landing gear to collapse. The aircraft's forward momentum brought it to a halt against a rising bank. There were no injuries to the two occupants.
The investigation
Investigators examined the aircraft and the fuel system following the accident. Upon inspection of the wreckage, it was discovered that the left fuel tank was empty. Approximately 30 litres of fuel had been drained from the right tank. The fuel selector was found in the position for the right tank.
Analysis of the flight logs and fuel levels indicated that the aircraft had flown for a duration that would have exhausted the left tank's contents. The pilot had noted earlier that the left tank had a lower quantity, yet the engine failure occurred after a period of flight that was inconsistent with the remaining fuel if the left tank had been used.