What happened
On 15 March 2008, a Druine D.31 Turbulent, registration G-APTZ, was participating in a pre-season display practice at Headcorn Airfield. The routine involved a three-aircraft formation performing passes under a set of limbo poles positioned approximately 5 feet above the ground.
During the maneuver, the pilot of G-APTZ followed the leader of the formation, executing a descending approach toward the poles. While positioned near the poles, the aircraft experienced an uncommand to change its flight path. The pilot was unable to recover the aircraft before it struck the ground. The impact caused the aircraft to break up, with the wings detaching and the engine propeller striking the earth. The pilot sustained minor injuries.
The investigation
Investigators examined the flight sequence and the airfield environment. At the time of the accident, a Cessna 172 was operating in the circuit on the active runway. A CAA Display Authorisation Evaluator, observing the practice, noted that the aircraft's flight path changed abruptly just before passing under the bunting.
Evidence from the ground indicated the aircraft hit the surface in a level attitude, likely on the right main wheel. The investigation also considered the possibility of the aircraft striking the bunting, but found no evidence to support this. The pilot noted that while he did not see the other aircraft, turbulence from the Cessna 172 might have been carried toward the practice area by the light south-easterly wind.
Findings
- The aircraft likely encountered a disturbed air mass that caused the uncommanded change in flight direction.
- The pilot was unable to regain control of the aircraft before the ground impact.
- The presence of other traffic in the circuit may have contributed to the presence of turbulence in the practice area.