What happened
On 23 October 2022, an MDM-1 Fox glider, registration SP-3828, was performing a training flight at the Rudniki aerodrome (EPRU) in Poland. The glider was being towed by a WT-9 "Dynamic" aircraft as part of an aerobatics training program.
Shortly after takeoff, at an altitude of approximately 80 to 90 meters, the pilot of the tow plane reported an engine problem, noting vibrations and a loss of power. As the tow plane attempted to return to the aerodrome, the flight team initiated a right turn. During this maneuver, the glider crew released the tow cable. Following the release, the glider's nose rose slightly before it entered a right spin. Due to the low altitude and the developing spin, the crew was unable to recover, and the glider struck the ground. The instructor and the trainee pilot both sustained fatal injuries.
The investigation
The PKBWL investigation examined the technical condition of both aircraft, the maintenance history of the tow plane's engine, and the flight dynamics of the accident sequence. Investigators analyzed the engine's power plant, discovering that excessive carbon deposits and the poor condition of the spark plugs in cylinder 1 had caused a loss of compression and subsequent power drop. The investigation also reviewed the glider's weight and balance, noting that the aircraft was operating with an exceeded maximum takeoff mass and an "extra forward" center of gravity. Furthermore, the investigators looked into the flight maneuvers performed by both the glider crew and the tow plane pilot during the emergency return to the aerodrome.