What happened
On April 11, 2019, at approximately 16:30 LMT, an EC 135P2+ helicopter, operating a HEMS mission for LPR, landed at Warsaw-Babice (EPBC) to refuel after transporting a patient to a hospital in Warsaw. Following refueling, the crew received clearance to depart for their base in Płock. During the initial climb on a course of 10° (DS 10), the helicopter crew followed standard circuit procedures.
While climbing through approximately 1,500 ft, the medical paramedic noticed an aircraft to the left of the helicopter. Although the pilot performed a visual scan and did not initially detect the aircraft on the SDM 68 or ACAS displays, the situation changed during the climb to the second turn. The pilot then observed the silhouette of an aircraft emerging from beneath the helicopter on the right side, estimated to be at a separation of approximately 50 meters below. The pilot subsequently lost visual contact with the aircraft after completing the second turn.
At the same time, a Cessna 172 was performing training circuits. The student pilot of the Cessna had requested landing via radio, and the tower granted permission with an explicit instruction to "be mindful of the departing helicopter," which the pilot acknowledged. As the Cessna landed, the helicopter was climbing to its first turn on the right-south side of the DS 10 track. Realizing a collision risk, the student pilot aborted the climb and maintained an altitude of approximately 70 kt. To maintain separation, the student pilot cut the first turn, moving from the left to the right side of the helicopter's flight path.
The investigation
The PKBWL investigation established the flight paths of both aircraft and the communications between the tower and the Cessna 172 crew. The investigation confirmed that the tower had issued a specific warning to the student pilot regarding the departing helicopter. The commission also reviewed the cockpit observations made by the helicopter crew and the maneuvers performed by the student pilot to avoid the encounter.