What happened
On 9 October 2008, an RAF 2000 gyroplane, registration G-CBCJ, was performing a private flight from Little Rissington to Henstridge Airfield. The flight was part of a return journey following an annual inspection. The pilot was accompanied by another gyroplane flying in company.
During the descent toward Henstridge, the aircraft accelerated. The accompanying pilot, flying in a position behind G-CBCJ, noted that his own airspeed had increased to 95 mph, which was above the permitted maximum speed of 70 mph for the aircraft type. Shortly after this period of high speed, the pilot of the following aircraft could no longer see G-CBCJ. Witnesses on the ground reported hearing loud noises, including sounds similar to engine misfiring, followed by a large bang and seeing debris falling from the sky. The aircraft struck the ground in a near-vertical attitude, resulting in 1 fatality.
The investigation
Investigators examined the wreckage and recovered components including the tail boom, fin, rudder, and propeller blades. Analysis of the wreckage distribution showed that the main rotor blades had struck the aircraft's fin and rudder multiple times. Specifically, reconstruction of the tail surfaces revealed three distinct strikes from the rotor blades.
Engine examinations showed no evidence of mechanical failure prior to the impact, and the carburettor heat air box was found in the hot position. The investigation also reviewed the aircraft's maintenance history, noting that the airframe and engine had relatively low hours, and the annual inspection had been completed recently. The investigation also considered the flight conditions, noting that the pilot was flying near sunset in cold, damp conditions.
Findings
- The aircraft experienced a pitch excursion that caused the main rotor to strike the propeller, fin, and rudder.
- The unmodified RAF 2000 model lacks a horizontal stabiliser, making it susceptible to longitudinal instability at higher speeds.
- The aircraft was likely operating at or near its never-exceed speed (VNE) during the descent.
- The pilot may have been distracted by environmental factors or internal tasks, preventing the detection of the pitch instability.
- The aircraft was not equipped with the CAA-approved horizontal stabiliser modification designed to improve stability.