What happened
On 26 August 2017, a DH82A Tiger Moth, registration G-ADXT, was conducting an introductory flight near Compton Abbas Airfield, Dorset. The aircraft was carrying a pilot and one passenger. During the takeoff roll from Runway 08, the engine was heard to misfire, though the aircraft successfully became airborne and continued to climb.
Shortly after departure, the pilot transmitted to the airfield that the engine was running roughly and expressed his intention to perform a 180-degree turn to land on Runway 26. Witnesses observed the aircraft on its approach, noting that it appeared to be flying at a low airspeed. As the aircraft reached approximately 200 feet above the airfield, the nose pitched down sharply. The aircraft then entered a steep, descending left turn and failed to recover before impacting a crop field. The impact was followed by a post-crash fire. Both the pilot and the passenger sustained two fatal injuries.
The investigation
AAIB investigators examined the wreckage and found the aircraft was structurally intact prior to the impact. The investigation focused on the engine's performance and the aircraft's flight path. While the engine was heard misfiring during takeoff, investigators could not definitively determine the cause of the rough running due to the extensive damage caused by the fire and impact.
Testing of the aircraft's flight characteristics revealed that at low power settings, the aircraft's rate of descent increases significantly. Investigators also looked into the possibility of the passenger inadvertently restricting the movement of the flight controls during the emergency. The investigation also reviewed the engine's maintenance history, noting previous reports of low compression and recent work on the magneto and cylinder heads.
Findings
- The engine exhibited symptoms of rough running or misfiring during the initial climb.
- The aircraft entered a steep, nose-down descent and a left turn from which it did not recover.
- The exact reason for the final, rapid descent—whether due to a stall, an attempt to regain airspeed, or a change in landing site—could not be determined.
- The engine was still turning at the time of impact, as evidenced by the broken propeller blades.