What aircraft was involved and where did it happen?

The accident on 2010-08-22 involved a Swift S-1, registration G-IZII, at Shoreham Airfield, West Sussex, GB.

What was the probable cause of the accident?

The aircraft stalled and departed controlled flight because the pilot failed to monitor the airspeed during a low-level turn, exacerbated by increased drag from rudder and airbrake usage.

Glider Stall During Airshow Display at Shoreham

A Swift S-1 glider stalled and crashed during a low-level turn at Shoreham Airfield, resulting in serious injuries to the pilot.

What happened

On 22 August 2010, a Swift S-1 glider, registration G-IZII, was participating in an aerial display at Shoreham Airfield, West Sussex. The flight was part of a coordinated team performance involving a tug aircraft and Twister jets. During the display, the glider pilot disconnected from the tug aircraft following a series of aileron rolls.

After releasing from the tow, the pilot attempted to position the aircraft to land at the launch point. Realising the aircraft was likely to overshoot the intended target, the pilot initiated a left turn to land downwind. During this low-level manoeuvre, the aircraft's airspeed decreased, and the pilot's attention was focused ahead rather than on the airspeed indicator. The glider subsequently stalled and departed controlled flight, impacting the runway surface. The impact caused substantial damage to the aircraft and resulted in one serious injury to the pilot.

The investigation

Investigators examined video footage from spectators and cockpit cameras, alongside photographic evidence, to reconstruct the flight path. The investigation established that the pilot was performing a low-level turn at a very low altitude, approximately 35 to 40 feet above the ground.

Analysis of the aircraft's handling revealed that the use of rudder and the intermittent selection of airbrakes during the turn increased drag. The investigation also noted that the pilot's visual scan was limited, as he was looking ahead and slightly to the left of the nose, failing to monitor the airspeed indicator for approximately eight seconds prior to the stall. Furthermore, the investigation reviewed the weather reports and display instructions, noting that the definition of "significant cloud" was potentially ambiguous, which may have influenced the decision to proceed with the display.

Findings

The glider stalled due to a loss of airspeed during a low-level turn.
The pilot's attention was divided between maintaining the flight path and managing the aircraft, leading to a lack of airspeed monitoring.
The application of rudder and airbrakes during the turn increased drag and contributed to the loss of energy.
The pilot was attempting to land downwind, which likely led to an inadvertent reduction in airspeed to match the perceived groundspeed.
The stress of performing low-level manoeuvres at the edge of safety margins likely affected the pilot's ability to maintain sufficient control inputs.