What happened
On 30 June 2018, a DH82A Tiger Moth, registration G-ANRM, was conducting a training flight at Sywell Aerodrome in Northamptonshire. The aircraft, operated by a vintage flying experience provider, was performing its third flight of the day. After two successful landings on the grass runway, the pilot was on short final for Runway 03R.
During the landing flare, a sudden and unpredictable gust of wind struck the aircraft. This caused the plane to roll sharply to the left. The pilot attempted to correct the roll and initiate a go-around, but the low-speed aileron authority was insufficient to counteract the movement. Consequently, the left wing struck the ground, causing the aircraft to rotate and eventually come to rest inverted. Both the pilot and the passenger sustained minor injuries.
The investigation
The investigation examined the wind conditions at the time of the accident and the aircraft's handling characteristics. While the pilot had observed a windsock indicating a wind direction approximately 10 degrees to the right of the runway heading, official airfield information reported a wind of 040 degrees at 15 knots.
Further inspection of the aerodrome revealed discrepancies in wind indications. The investigation found that different windsocks on the airfield were providing conflicting information, and the anemometer reading from Sywell Information differed from the windsock nearest to the incident site. Additionally, the investigation noted that while the operator's guidelines recommend avoiding crosswinds exceeding 15 knots, the aircraft's original notes contained no specific wind limitations.
Findings
- The aircraft's low wing loading made it highly susceptible to sudden gusts.
- A sudden wind gust during the flare caused an uncorrectable left roll due to reduced aileron effectiveness at low speeds.
- Conflicting wind direction indicators were present on the airfield at the time of the accident.
- The wind conditions were near the operator's recommended limit for crosswind operations.