What happened
On June 24, 2017, at approximately 20:40 LMT, a Cessna 152 was taxiing at the EPSO aerodrome toward a fuel dispenser for refueling. The aircraft was following another Cessna 152 that was already queued for fuel. The first aircraft, operated by a flight training center, came to a stop at a safe distance from the second aircraft, which was being refueled by a mechanic and a group of students.
Following the completion of the refueling process, the second aircraft was pushed onto the grass area to the left of the taxiway. As the pilot of the first aircraft proceeded to taxi past the stationary aircraft, the mechanic signaled for the movement to continue. During this maneuver, the ground crew began pushing the second aircraft. This resulted in a collision between the left wings of the two aircraft, specifically the left wingtip of the first Cessna 152 striking the leading edge of the left wing of the second Cessna 152.
The investigation
The investigation focused on the coordination between the ground crew and the taxiing pilot. The inquiry established that the mechanic issued the command to begin pushing the aircraft prematurely. Furthermore, the investigation examined the actions of the crew in the taxiing aircraft, noting that they failed to maintain a principle of cautious observation regarding the movement of the aircraft being pushed.