What happened
On 13 July 2018, an Extra 400, registration D-EXKG, was preparing for a private flight from Oban Airport to Shoreham. The aircraft was operating near its maximum takeoff weight, necessitating the use of the full length of Runway 19. During the takeoff roll, the pilot reached a speed of approximately 80 kt before noticing a flock of birds at low level near the end of the runway. Fearing the aircraft would lack the performance to climb above the birds, the pilot decided to abort the takeoff.
While attempting to decelerate, the pilot applied significant braking effort while trying to avoid wheel lock-up. However, the aircraft could not stop within the remaining paved surface. The aircraft overran the runway, struck the airfield boundary fence, and eventually came to a rest in a patch of bushes near the shoreline. There were no injuries to the pilot or the two passengers on board.
The investigation
The investigation examined the aircraft's performance capabilities and the sequence of the braking maneuver. Data from the Pilots Operating Handbook (POH) indicated that at maximum takeoff weight, a lift-off speed of 73 kt would require a takeoff run of roughly 480 m, while a landing roll would require approximately 280 m. In this instance, the decision to brake was made at 80 kt, which increased the required stopping distance.
The pilot reported that during the final 25 metres of the runway, the brakes appeared to lose effectiveness, which he attributed to overheating. The aircraft struck the perimeter fence and bushes at a speed of approximately 5 kt. The investigation also noted the pilot's practice of using higher takeoff speeds than those specified in the POH due to perceived performance limitations.
Findings
- The pilot initiated a rejected takeoff at a speed of approximately 80 kt, which was higher than the standard 73 kt lift-off speed.
- The decision to abort the takeoff was prompted by the presence of birds at the end of the runway.
- The aircraft failed to stop before the end of the paved runway, leading to the excursion.