What happened
On 29 May 2000, a DH82A Tiger Moth, registration G-AHMN, was performing a private demonstration flight from Middle Wallop Airfield in Hampshire. The flight began under favorable weather conditions, with the pilot noting a northerly wind of 12 to 15 knots. Following standard procedures, the pilot completed engine warm-up and control checks before taxiing toward a takeoff heading of approximately 300°(M).
Due to active parascending activity in the area, the pilot was unable to use a preferred westerly takeoff run and instead utilized an upslope direction. During the takeoff roll, the pilot maintained a wings-level climb. However, as the aircraft crested a rising slope, it encountered significantly stronger winds coming from the left. This wind change caused the aircraft to drift toward a large building located ahead of the flight path.
In an attempt to avoid the structure, the pilot closed the throttle and attempted a right-hand turn. Because the aircraft was at a very low airspeed, the left wing dropped, striking the ground. The aircraft subsequently collided with a small bush and came to rest on its left side. The pilot sustained minor injuries, including a cut to the nose, while the passenger remained uninjured.
The investigation
Investigators examined the wreckage in a hangar at Middle Wallop and found the fuselage had sustained relatively little damage, suggesting a low-speed impact. The right wing had suffered significant damage, including a main spar failure in the outboard section, though no evidence of pre-impact failure was found in the bracing wires or struts.
An examination of the cockpit revealed that the leading edge slat locking lever was in the unlocked position. In this configuration, the slats are free to extend under aerodynamic loads at low speeds. While the left wing slat cable was found to be severed, this was attributed to damage caused during the recovery of the aircraft rather than a mechanical failure prior to the accident.
Findings
- The primary cause of the accident was the sudden increase in wind strength and a change in wind direction as the aircraft crested the ridge.
- This wind shift caused the aircraft to drift toward an obstacle.
- The pilot's attempt to abandon the takeoff was initiated too late.
- The combination of low airspeed and the attempt to bank the aircraft resulted in a wing drop at the stall.