What happened
On 6 March 2010, a Schleicher ASK 13 glider, registration EI-GLD, was performing a private flight near Punchestown, Co. Kildare. After an uneventful aerotow to 2,000 feet, the pilot released from the tow plane and encountered insufficient wave lift to maintain altitude. Consequently, the pilot decided to execute a crossfield landing at the southern end of Gowran Grange Airfield.
During the final approach, the aircraft descended below the intended glide path. In an attempt to correct the low altitude, the pilot initiated an undershoot procedure, which involves diving to increase airspeed. However, the aircraft remained too low and struck electricity supply cables running perpendicular to the flight path. The impact caused the glider to stall and nose-dive into a ploughed field adjacent to the landing area. The pilot was able to exit the aircraft unaided and escaped with only minor injuries.
The investigation
The AAIU examined the flight sequence, the aircraft's configuration, and the environmental conditions. Investigators noted that the aircraft's airbrakes were partially deployed at the time of impact. The investigation also looked into the mechanics of the undershoot procedure and the pilot's management of the descent profile. The investigation confirmed that the contact with the cables caused a brief local power outage due to a tripped circuit breaker at a nearby substation.
Findings
- The glider's descent profile fell below a safe, stabilized approach path.
- The pilot did not take the necessary corrective action of fully retracting the airbrakes to recover altitude.
- The failure to retract the airbrakes likely increased drag during the attempted undershoot, exacerbating the rate of descent.
- It is possible the pilot was unaware that the airbrakes remained partially deployed during the maneuver.