What happened
On 16 August 2003, an Avid Speedwing Mk 4, registration G-BVAA, was performing a private flight to a grass landing area at Siege Cross Farm Strip, Thatcham. While descending on final approach to the 460-metre northern-facing strip at approximately 400 feet, the aircraft entered an area of sinking air. The pilot responded by increasing power, which successfully stabilized the descent.
However, as the aircraft approached the boundary hedge of the landing area, it encountered a second, more intense area of heavy sink. The pilot was unable to compensate for this sudden loss of altitude, causing the aircraft to strike the top of the hedge. Following this impact, the aircraft made a heavy touchdown in a relatively level attitude. The aircraft traveled approximately 60 feet along the ground before the nose landing gear collapsed rearwards, leaving the aircraft in a nose-down position. The incident resulted in no injuries to the pilot, but caused damage to the flaperon mounting points, the nose landing gear, and one propeller blade, which was found to be bent and split.
The investigation
The investigation was based on the accident report provided by the pilot and meteorological aftercast data. Investigators examined the atmospheric conditions at the time of the occurrence. While the pilot believed the surface wind was south-westerly, meteorological data from four nearby airfields indicated that the wind was actually an east-north-easterly at a maximum of 12 knots. The weather was generally fine, with no significant cloud cover or cumulonimbus present, and a QNH of 1020 HPa.
Findings
- The primary cause of the accident was the encounter with heavy sink that exceeded the aircraft's performance capabilities during the final stage of approach.
- The aircraft struck a boundary hedge due to the inability to arrest the sink rate.
- The subsequent nose landing gear failure was a direct result of the heavy touchdown following the hedge strike.