What aircraft was involved and where did it happen?

The accident on null involved a aircraft, registration EI-GMB, at IE.

What was the probable cause of the accident?

A misjudgment of the necessary glide angle, potentially exacerbated by the use of bifocal sunglasses and the deployment of airbrakes, led the aircraft to strike a boundary hedge and subsequently collide with a stationary sailplane.

Two Sailplanes Damaged in Collision at Kilrush Airfield

An Alexander Schleicher ASW 17 collided with a stationary aircraft and a boundary hedge during landing at Kilrush Airfield, resulting in substantial damage to both aircraft.

What happened

On 10 August 2018, during a club-organized flying event at Kilrush Airfield, Co. Kildare, a single-seat Alexander Schleicher ASW 17, registration EI-GMB, was on final approach to runway 29. While attempting to manage the descent angle and airspeed with airbrakes fully extended, the pilot realized the aircraft was too low to clear the airfield boundary hedge.

In an attempt to avoid the obstacle, the pilot pulled up, causing the tailplane to strike the top of the hedge. The impact caused the aircraft to pitch nose-down, leading the main landing gear to strike the port wing of a stationary Alexander Schleicher ASK 21, registration EI-GLA, which was positioned at the runway threshold. Both aircraft sustained substantial damage. The pilot of EI-GMB and a student aboard EI-GLA were uninjured, though an instructor preparing to board the stationary aircraft sustained minor facial bruising while taking evasive action.

The investigation

The AAIU examined the flight history, aircraft condition, and pilot factors. The investigation established that the pilot of EI-GMB had recently begun using prescription bifocal sunglasses, which may have affected depth perception due to the aircraft's reclined seating position. The investigation also reviewed the operational practices of the Dublin Gliding Club and the Irish Gliding & Soaring Association (IGSA) regarding the positioning of aircraft on active runways during club events.

Findings

The pilot's use of new bifocal sunglasses, combined with the reclined seating position, likely contributed to a misjudgment of the glide angle required to clear the hedge.
The deployment of airbrakes on final approach reduced the aircraft's glide range.
The presence of a stationary aircraft at the runway threshold acted as a distraction and increased the risk of collision.
The pilot's attempt to correct the low altitude resulted in the tailplane striking the boundary hedge.

Safety action

Following the accident, the IGSA announced intentions to update its operational regulations to ensure gliders are only positioned on active runways when it is safe to do so. Additionally, the Dublin Gliding Club issued new guidance instructing members to keep runways clear and to perform pre-flight checks in parking areas rather than on the runway threshold.