What happened
On 22 August 2015, a Zenair CH 601 XL (registration 54-AS and 54-ASJ) departed from Sandown Airport on a private flight intended for France. The weather conditions were favorable, with a light north-easterly wind. Following a normal takeoff roll on the grass runway, the aircraft lifted off after approximately 350 metres.
Immediately upon rotation, the aircraft began an unplanned left turn. The pilot attempted to counteract this movement by applying right rudder and right aileron, but these control inputs appeared to have little effect. In an attempt to stabilize the aircraft's track, the pilot reduced power at an altitude of roughly 30 feet. While this briefly helped reduce the bank angle, the pilot reapplied power to avoid nearby trees. The aircraft continued in a nose-high, climbing left turn, which eventually resulted in a loss of airspeed. The aircraft then stalled and entered an incipient spin to the left, crashing into a grass field approximately 300 metres from the runway threshold. The impact caused a post-crash fire, and the pilot sustained serious injuries.
The investigation
Investigators reviewed witness accounts, photographs, and video footage of the flight. The video and still images confirmed that the ailerons were in a neutral position at the start of the takeoff roll and showed the pilot's right-hand control deflections during the turn. The pilot, who had built the aircraft from a kit, suggested the possibility of a jammed aileron, though the investigation could not confirm this.
Technical analysis noted that while the aircraft's documentation listed a 59 kW engine, the engine installed was likely a 75 kW Rotax 912 ULSFR. The investigation also noted the aircraft's flight control configuration, which included a 'hingeless' aileron system and an all-flying vertical tail.
Findings
- The aircraft entered an unintended left turn immediately after liftoff.
- The pilot's control inputs to counter the turn were ineffective.
- The sustained nose-high pitch attitude led to a reduction in airspeed.
- The loss of airspeed ultimately caused the aircraft to stall and enter an incipient spin.
- There was insufficient evidence to determine the specific reason why the initial left turn occurred.