What happened
On 2 January 2006, a modified Avid Aerobat, registration G-LAPN, was performing a private flight at Otherton, Staffordshire. During the takeoff roll on Runway 25L, the pilot noted a distinct change in the engine's sound. Upon checking the engine RPM gauge, the pilot observed a reduction of approximately 250 RPM.
As the aircraft reached the end of the available runway, there was insufficient distance remaining to stop. The aircraft overran the runway and struck a single-track road characterized by two ruts separated by a raised grassy ridge. The impact launched the aircraft into the air to a height of 5 to 10 feet before it fell back to the ground in a nose-down attitude. The incident resulted in no fatalities and no injuries to the pilot or the passenger. The aircraft sustained damage to the propeller and both wingtips, and mud was found within the engine cooling air intakes.
The investigation
The investigation was based on the aircraft accident report submitted by the pilot and meteorological data from the Met Office. The pilot had performed engine power checks at the holding point, which were satisfactory, and had verified that there was no fuel contamination during a pre-flight drain sample.
Investigators examined the engine performance during the roll and noted the pilot's assessment that the power loss was likely caused by fuel or air starvation. Meteorological analysis revealed that at the time of the accident, a ridge of high pressure was situated over England and Wales. According to the Met Office carburettor icing probability chart, there was a probability of serious carburettor icing at any engine power setting under the prevailing atmospheric conditions.
Findings
- The aircraft overran the runway due to insufficient remaining distance to stop after the engine power decreased.
- The reduction in engine RPM occurred during the takeoff roll.
- Atmospheric conditions at the time of the accident indicated a high risk of carburettor icing.