What happened
On 15 September 2023, a private flight involving an RAF 2000 GTX-SE, registration G-CDJN, was departing from Great Heck Airstrip in North Yorkshire. During the pre-flight process, the pilot briefly exited the aircraft to retrieve forgotten items. Upon returning and restarting the engine, the pilot proceeded with the takeoff sequence.
Shortly after liftoff, the aircraft experienced a loss of performance and began to descend. Faced with a line of trees directly ahead and a railway line to the left, the pilot maneuvered the gyrocopter toward a nearby canal. Due to the narrowness of the canal banks and the presence of foliage, the pilot performed a forced landing in the water. During the impact, the main rotor blades detached from the aircraft. The gyrocopter sank, but the pilot was able to exit through the passenger door and escaped with no injuries.
The investigation
Investigators examined the circumstances surrounding the loss of engine performance and the pilot's actions during the pre-flight phase. The investigation established that the pilot had interrupted his checklist to retrieve a pen and a sun cap. After re-entering the aircraft, the pilot noted that the rotor took an unusually long time to reach takeoff RPM.
Analysis of the aircraft's equipment revealed that G-CDSB was not equipped with a rotor brake warning light, a feature not included in the standard build for this model. Furthermore, while the pilot had manually added a check for the rotor brake to his personal checklist, the original manufacturer's checklists did not explicitly require a verification that the brake was disengaged before pre-rotation.
Findings
- The primary cause of the descent was that the rotor brake remained applied during takeoff.
- The interruption of the pre-flight checklist allowed the brake to be inadvertently left engaged.
- Friction caused by the applied brake during the pre-rotation process likely increased the brake's effectiveness as it warmed up, contributing to the loss of performance.
- The pilot's limited landing options were due to the proximity of trees, a railway line, and narrow canal banks.