What happened
On February 25, 2021, at approximately 16:50 local time, two aircraft were operating in the traffic pattern at Warsaw-Babice (EPBC) under VFR conditions. The first aircraft, a Cessna 172 with registration SP-KLP, was performing a training flight. The second aircraft, a Diamond DA20-A1 with registration SP-ACS, was conducting a recreational flight.
While the crew of SP-KLP was completing a training circuit toward runway 28L, the pilot of SP-ACS contacted AFIS, stating an intention to enter the traffic pattern at the third turn. However, as the crew of SP-KLP exited their third turn, they observed SP-ACS flying significantly to the left of the pattern and approximately 300 feet lower than their position. As SP-ACS began its turn toward runway 28L, the crew of SP-KLP determined that the aircraft would cross their flight path too closely. To mitigate the risk, the crew of SP-KLP reduced speed, and subsequently performed a go-around as suggested by the AFISO.
The investigation
The PKBWL investigation relied on statements from both flight crews and the AFISO. The investigation could not definitively reconstruct the exact flight paths because the aircraft were not equipped with flight parameter recorders or transponders, and the AFIS recording device was malfunctioning at the time of the incident.
Analysis of the reported intentions versus the actual flight paths revealed that while the pilot of SP-ACS reported an intention to enter at the third turn, the actual entry occurred during the fourth turn. The investigation established that if the pilot of SP-A CS had followed the reported plan, the aircraft would have remained at a safe distance from SP-KLP.
Findings
- The crew of SP-ACS performed an improper traffic pattern entry by flying on the outside of the pattern and entering at the fourth turn rather than the third.
- The crew of SP-KLP correctly identified the collision risk and took appropriate action to maintain separation.
- High traffic volume within the traffic pattern contributed to the difficulty of integrating arriving aircraft safely.
- The AFISO provided necessary traffic information to both crews during the sequence.