What happened
On 16 March 2007, an Ikarus C42 FB100 VLA, registration G-WOLV, was preparing for a private flight from Lower Upham Airfield in Hampshire. The pilot, an experienced instructor, was conducting a flight to familiarise a passenger with the aircraft. During the takeoff roll on a grass runway, the aircraft appeared to accelerate and rotate normally. However, once airborne, the aircraft exhibited a reluctance to climb.
At an altitude of approximately 20 to 30 feet, the left wing dropped and struck the ground. This initiated a cartwheel motion that rotated the aircraft roughly 270 degrees. The impact caused the engine, propeller, and nose landing gear to detach from the airframe, and the left wing tip sustained damage. The two occupants evacuated the aircraft via the door; the pilot sustained no injuries, while the passenger suffered one minor injury.
The investigation
The AAIB examined several factors that may have contributed to the loss of altitude during the initial climb. The investigation considered the runway conditions, noting that the takeoff was performed in an uphill direction, which is standard practice at the airfield to mitigate noise. The investigators also reviewed the aircraft's weight and balance, noting that the aircraft was approximately 8 kg above its maximum takeoff weight, though the pilot believed the actual weight might have been 18 kg below the recorded limit.
Furthermore, the investigation looked into potential engine issues. While the pilot reported normal engine RPM during pre-takeoff checks, the engine lacks a selectable carburettor heat control. This means pilots must rely on monitoring oil temperature to prevent icing. The investigation also considered whether a sudden increase in wind or a subtle loss of power during the ground roll could have influenced the aircraft's performance.
Findings
- The uphill runway slope may have created an illusion that the aircraft was not climbing normally or could have hindered the success of a potential stall recovery.
- There was a possibility of a subtle loss of engine power during the takeoff run.
- The aircraft was approximately 8 kg over its maximum allowable takeoff weight.
- A sudden increase in wind strength could have impacted the climb performance.