What happened
On 27 October 2019, a Jabiru UL-45 and registration G-ROYC was performing a private flight at Gransden Lodge Airfield. The aircraft was being operated by two qualified pilots, with the pilot in the right seat acting as the pilot flying. During the approach to the runway, the pilot determined the aircraft was unstable and initiated a go-around at a low altitude.
During the maneuver, the aircraft failed to maintain its altitude, instead descending and drifting toward the left side of the runway. In this area, a SZD-51 glider, registration G-CHEK, was stationary and waiting for a winch launch. The Jabiru UL-45 struck the tail of the parked glider, causing substantial damage to both aircraft. One occupant of the Jabiru UL-45 sustained a minor injury, while the pilot of the glider was uninjured.
The investigation
The AAIB investigation examined the aircraft's configuration, weight, and the actions of the crew. It was noted that the aircraft had been modified with electric flaps, featuring a switch that latches in the fully retracted position. The investigation also reviewed the aircraft's weight, finding it was at 463.5 kg, which exceeded the maximum permitted gross weight of 450 kg.
Investigators also looked into the cockpit ergonomics, noting that the throttle position was unusual for the pilot, and that the flap selector was only accessible to the pilot in the left seat. The investigation also considered the lack of clearly defined roles and responsibilities between the two pilots during the flight.