What happened
On June 5, 2024, a Pipistrel Virus SW100, registration SP-SIVA, was performing a flight from Nadolna to Warsaw-Babice (EPBC). At the time, glider operations were underway at the aerodrome, utilizing runway 28R, while other aircraft were assigned to runway 28L.
Following instructions from the AFIS coordinator, the pilot of SP-SIVA executed a left-hand pattern for runway 28L. However, during the final turn of the pattern, the pilot failed to maintain the prescribed rectangular flight path, drifting across the approach axis of the parallel runway. At approximately 17:15 LMT, at an altitude of no more than 100m AGL, the Pipistrel Virus SW100 flew extremely close to an approaching SZD-50-3 Puchacz glider. An instructor on board the glider estimated the separation between the two aircraft to be approximately 10 meters. The instructor immediately took control and applied aerodynamic brakes. The powered aircraft passed beneath the glider, slightly ahead of it, but due to the glider's momentum, the two aircraft remained in very close proximity before both eventually landed safely on their assigned runways. Prior to the encounter, the crews had not observed one another.
The investigation
The PKBWL examined the flight paths, the communication between the pilot and AFIS, and the visibility/weather conditions. The investigation established that weather conditions were optimal (CAVOK) with light westerly winds. The investigation also reviewed the roles of the AFIS coordinator and the glider flight controller, noting that while AFIS provides information, it does not provide separation.
Findings
- Improper planning and execution of the southbound pattern by the pilot of SP-SIVA, which resulted in entering the approach zone of the parallel runway.
- Failure to maintain the prescribed rectangular flight path.
- Lack of effective scanning and situational awareness by the pilot of the powered aircraft.
- Excessive entry speed into the fourth turn of the pattern, which caused the turn to widen significantly toward the parallel runway approach.
- Inadequate observation by the glider flight controller, who likely failed to notice the deviation of the powered aircraft.
- Insufficient scanning by the glider crew (instructor and student), who were likely focused on the landing approach and failed to detect the approaching aircraft.