What happened
On 20 June 1998, a Piper PA-38-112, registration G-BPJF, was performing a private flight departing from Derby Airfield. The flight was intended to return the aircraft to Woodford, Cheshire, following an earlier visit to Derby. While weather conditions were generally favorable, visibility was limited to 8 km due to light rain showers, and the grass runway was wet.
During the takeoff roll on Runway 17, the pilot struggled with directional control because the lack of a centerline reference on the grass surface made it difficult to maintain the aircraft's path. As the takeoff progressed, the pilot noticed insufficient acceleration. Fearing there was not enough remaining runway to safely abort the maneuver without hitting the boundary, the pilot continued the roll. Approximately 30 meters before the end of the available runway, the pilot attempted to lift the nose, but the main wheels remained in contact with the ground. The aircraft struck a hedgerow, causing the wings to detach, fuel lines to rupture, and significant damage to the propeller and left tailplane. The aircraft eventually came to rest on its port side in a field beyond the hedge.
The investigation
The investigation examined the aircraft's performance requirements and the pilot's experience. Calculations determined that, given the aircraft's weight and the ambient conditions, a takeoff distance of 575 metres was necessary to reach a height of 50 feet. The available takeoff run was only 525 metres, meaning any loss of performance would likely result in an overrun.
Investigators noted that the pilot had limited experience with grass runway operations, having previously performed only two takeoffs from such surfaces, and this was his first encounter with wet grass. Furthermore, the pilot's training had primarily occurred on tarmac runways. The investigation also noted that while the magnetos were switched off following the impact, the carburettor heat control was found partially engaged, potentially moved during the evacuation.
Findings
- The primary cause of the accident was the pilot's failure to abort the takeoff when it became apparent that acceleration was insufficient.
- The pilot's preoccupation with maintaining directional control on the grass surface led to a lack of awareness regarding the diminishing runway length.
- The aircraft's required takeoff distance exceeded the available runway length under the prevailing conditions.
- The pilot's lack of experience with wet grass runway operations contributed to the difficulty in managing the takeoff roll.