Incident Overview
On 25 February 2021, at approximately 16:50 local time, an incident occurred at Warsaw-Babice Airport (EPBC) involving two aircraft: a Diamond DA20-A1 (registration SP-ACS) and a Cessna 172 (registration SP-KLP). The incident was classified as an "incident" by the Polish State Commission on Aircraft Accident Investigation (PKBWL). No injuries were reported and neither aircraft sustained damage.
Aircraft and Crew
SP-ACS was operated by Goldwings Flight Academy and was conducting a recreational flight under VFR. The pilot, a male holding a PPL(A) license, was the sole occupant.
SP-KLP was operated by IBEX-UL Sp. z o.o. and was performing training circuits. The crew consisted of an instructor, a 29-year-old male holding a CPL(A) license with a total flight time of 2200 hours (1200 hours at EPBC), and a pilot, a 47-year-old male holding a PPL(A) license who was resuming training after the winter break.
Sequence of Events
SP-KLP was conducting a training circuit for runway 28L. After passing the downwind leg, the crew heard a radio call from SP-ACS, which was returning from a cross-country flight and intended to join the traffic circuit at the third turn via VFR point ZULU. The SP-KLP crew attempted to visually acquire SP-ACS but did not see it during the third turn.
After exiting the third turn, the SP-KLP crew observed SP-ACS flying significantly to the left of the circuit and approximately 300 ft below. As SP-ACS began a turn toward runway 28L, the SP-KLP crew judged that the separation would be insufficient and reduced speed. SP-ACS proceeded to land on runway 28L, while SP-KLP executed a go-around, as suggested by the AFISO. After landing, neither crew reported any irregularities to the AFISO.
Investigation Findings
The investigation was based on crew and AFISO statements, as no flight data recorders or transponders were used, and the radio recording was lost due to a recorder malfunction. The intended plan for SP-ACS to join the circuit at the third turn from point ZULU was correct; however, the aircraft actually joined at the fourth turn, flying outside the circuit pattern. The SP-KLP crew correctly assessed the risk and took evasive action. The exact flight path of SP-ACS could not be unequivocally reconstructed.
Cause
The most likely cause of the incident was the improper execution of the entry into the traffic circuit by the crew of aircraft SP-ACS. A contributing circumstance was heavy traffic in the circuit, which made it difficult for incoming aircraft to integrate.