What happened
On 6 October 2013, an Auster J5K Aiglet, registration G-AMMS, was performing a private flight departing from Watchford Farm, near Honiton, Devon. The aircraft, carrying a pilot and one passenger, was operating from a 400 m grass runway that was damp and soft due to recent rainfall.
During the takeoff roll, the pilot applied full power and successfully lifted the tail. However, as the aircraft reached approximately 55-60 kt, it struggled to maintain flight, sinking back to the ground after an initial attempt at lift-off. Fearing the aircraft would run out of runway, the pilot elected to abort the takeoff by closing the throttle and applying the brakes. As the aircraft moved toward the end of the strip, it began to skid sideways. The aircraft eventually struck a wire-and-post fence at a low speed, resulting in no injuries to the occupants but causing damage to the left tailplane, elevator, and rear fuselage.
The investigation
The investigation examined the runway conditions, the aircraft's weight, and the pilot's decision-making process. It was noted that the aircraft was approximately 50 kg below its maximum takeoff weight. The pilot had previously operated from this location in an Auster 6A, which features a different wing loading profile, and the investigation looked at how the current aircraft's performance interacted with the soft, wet surface and the local topography.
Findings
- The takeoff roll was longer than anticipated due to the relatively high takeoff weight and the soft, damp nature of the grass surface.
- The pilot's decision to abort the takeoff was influenced by the aircraft's reluctance to remain airborne and the approaching end of the runway.
- The aircraft failed to stop effectively due to a combination of the downslope terrain and the slippery, wet grass surface.