What happened
On April 14, 2018, an ASK 21 sailplane, registration HB-1629, conducted a landing at Grenchen Airport (LSZG) following a recreational flight. During the approach, the pilot became aware that the grass runway 06L was closed according to the current Notice to Airmen (NOTAM). Believing there was insufficient time to transition to the parallel active runway, the pilot continued the approach on the closed grass strip.
As the aircraft descended, the pilot requested that the runway be cleared. At that moment, another aircraft, HB-YSH, was taxiing toward the threshold of the paved runway 06. Shortly before touchdown, the HB-1629 flew over several aircraft parked on the grass runway, one of which had its engine running. The incident resulted in one light injury to a passenger on board.
The investigation
The investigation examined the operational status of the airfield and the pilot's flight preparations. Records confirmed that a NOTAM had been issued for the day, stating that the grass runway 06L/24R was closed from 08:00 to 21:00 due to a general assembly. Additionally, the ATIS information indicated that only runways 06 and 06R were in operation and that the airspace had transitioned from a Control Zone to a Radio Mandatory Zone (RMZ).
Findings
- The pilot failed to adhere to the active runway information provided in the NOTAM and ATIS.
- The incident was caused by inadequate pre-flight or approach preparation.
- The landing presented a high risk because the pilot had limited maneuverability during the final approach phase, and the flight path crossed over stationary aircraft and an aircraft with an active engine.