What happened
On September 11, 2024, at the Piotrków Trybunalski airport (EPPT), several glider operations were underway, including instructional flights and pilot training. At approximately 13:00 LMT, a pilot operating a Grob G10 and2 “Astir CS”, registration SP-3841, was completing a thermal flight. After approximately 20 minutes of flight, the pilot was at an altitude of roughly 300 m AGL near the third turn of the aerodrome circuit and radioed an intention to land.
Simultaneously, ground operations were preparing a SZD-30 “Pirat” for a winch launch. While the pilot of the “Pirat” heard the “Astir”'s intention to land, the pilot of the Grob G102 “Astir CS” did not hear the subsequent radio communications between the ground crew and the winch operator. As the Grob G102 “Astir CS” transitioned to the landing straight, the pilot observed the “Pirat” glider on the ground, attached to the winch cable, moving slowly toward the takeoff position.
Due to unreadable radio transmissions, the winch operator did not initially receive the command to start the tensioning process, though an instructor in the air repeated the command. The winch operator eventually aborted the tensioning after noticing the approaching Grob G102 “Astir CS”. The pilot of the landing glider, unaware of the ground-level coordination, attempted to delay the landing by reducing airspeed to avoid the “Pirat”. This maneuver resulted in the glider flying just above the “Pirat” at minimum speed, leading to a stall. The Grob G102 “Astir CS” subsequently dropped and made a hard landing, striking the ground first on its tail and then with the forward fuselage. The aircraft sustained significant damage, though the pilot sustained no injuries.
The investigation
The PKBWL reviewed documentation provided by the investigating entity to establish the sequence of events and the breakdown in communication and flight execution.
Findings
- Improper approach execution resulting in a loss of airspeed and a subsequent stall prior to touchdown.
- Unclear radio communications between the glider launch site, the winch operator, and the pilot of the “Pirat”, which created an obstacle for the landing aircraft.
- A failure by the pilot of the Grob G102 “Astir CS” to select an unoccupied portion of the airfield for landing.
Safety action
- The user has reorganized the glider flight system at the Aeroklub Ziemi Piotrkowskiej. An instructor must now be present at the launch site before thermal flights begin to supervise ground traffic and launches and manage radio communications in coordination with the flight controller.
- The airport manager has taken steps to expand the usable area of the airfield for glider operations by developing previously unused parts of the takeoff field.