What happened
On 26 August 2021, a DH82A Tiger Moth, registration G-ANMO, was conducting a training flight at Headcorn Aerodrome in Kent. The purpose of the flight was to instruct a qualified pilot on the specific techniques required to land on a short, unlicenced grass strip.
During the second approach to the runway, the aircraft was flying at a low altitude and insufficient speed. As the aircraft neared a treeline, the airspeed decayed toward a stall. The left wingtip made contact with a tree, and the tailskid subsequently struck a power line supported by wooden pylons. The impact caused the aircraft to pitch down and eventually land on its back. Both occupants sustained minor injuries.
The investigation
The AAIB investigation established that the instructor was seated in the forward cockpit, where both the altimeter and airspeed indicator were unserviceable. Due to his seating position, the instructor also had a compromised view of the strut-mounted airspeed indicator and a limited forward view to provide instruction.
While the pilot flying was aware of the unserviceable instruments in the front cockpit, they were unaware that the instructor's ability to monitor the aircraft's performance was significantly hindered. Furthermore, the pilot flying did not communicate personal concerns regarding the flight conditions or the approach profile to the instructor. The investigation also noted that the instructor was experiencing time pressures that morning, which contributed to a lack of thorough briefing.
Findings
- The aircraft was flying too slow and too low on the final approach.
- The instructor's ability to monitor the approach was compromised by unserviceable instruments and a restricted field of view.
- A lack of communication between the crew meant that neither the instructor's visual limitations nor the pilot flying's concerns regarding the approach were addressed.
- The pilot flying focused on the touchdown point rather than monitoring the airspeed, relying on the instructor for speed corrections that the instructor was unable to provide effectively.