What aircraft was involved and where did it happen?

The accident on 2012-08-22 involved a Shadow Series CD, registration G-MYUS, at Near Laverstock, Salisbury, Wiltshire, GB.

What was the probable cause of the accident?

The pilot likely became incapacitated due to an underlying heart condition, leading the aircraft to enter an unrecovered spiral dive.

Fatal microlight accident near Salisbury investigation

A single-pilot microlight flight ended in a fatal spiral dive near Laverstock, Wiltshire, after the pilot failed to return to the airfield.

What happened

On 22 August 2012, a pilot was conducting a private VFR flight in a Shadow Series CD, registration G-MYUS, departing from Old Sarum. The aircraft, which had been specially modified with hand controls to accommodate the pilot's paraplegia, was intended for a one-hour route via Alderbury and Blandford Forum. After departing at 1347 hrs, the pilot transmitted a radio message at 1357 hrs indicating an intention to rejoin the airfield circuit.

When the aircraft failed to return as expected, a search was initiated. The wreckage was discovered in a field near Laverstock, approximately two miles southeast of the airfield. The aircraft had struck trees at a high speed before impacting the ground, resulting in the fatal injury of the pilot.

The investigation

The AAIB examined the wreckage and conducted flight testing on a representative Shadow Series CD to assess the aircraft's stability. The investigation found no evidence of mechanical failure or pre-existing defects in the aircraft. Flight tests revealed that while the aircraft possessed positive stability, it exhibited a weak divergent spiral mode. If the aircraft were displaced by more than 10 degrees from wings level, it could enter a tightening spiral dive that would continue to gain airspeed and altitude loss without pilot intervention.

Medical and pathological examinations were also central to the inquiry. While toxicology reports were negative for drugs or carbon monoxide, the post-mortem identified a heart condition in the pilot that could have potentially led to sudden incapacitation. This condition had been asymptomatic and was not subject to routine medical testing under the pilot's specific license type.

Findings

The aircraft struck the ground at a high speed, consistent with a spiral dive.

The pilot likely became incapacitated during the flight, preventing the necessary corrective actions to recover from an incipient spiral.

The aircraft's inherent stability characteristics allowed for a developing spiral dive if the aircraft was displaced from level flight by a gust or inadvertent control input.

A pre-existing, previously unidentified heart condition in the pilot provided a possible explanation for sudden incapacitation.