What happened
On June 18, 2017, at approximately 21:48 LMT, a Boeing 737-400 was taxiing to its assigned parking stand at Warsaw Chopin Airport (AD EPWA). The aircraft was scheduled for a subsequent flight later that day. Due to Schengen/Non-Schengen rotation requirements, the aircraft was assigned a parking stand that did not utilize a passenger boarding bridge.
During the taxiing process, the aircraft was forced to come to a halt. An investigation revealed that a ground service equipment (GSE) unit, consisting of a Mulag engine-powered tractor and passenger stairs, had been parked between the green line designating a winter snow storage area and the service road line. This placement resulted in the equipment encroaching upon the aircraft's Emergency Response Area (ERA).
Once the equipment was moved outside of the ERA, the aircraft was able to continue its taxiing to the designated parking position.
The investigation
The investigation focused on the positioning of the ground equipment and the compliance of the ground handler with airport operational procedures. It was established that the personnel operating the Mulag tractor and passenger stairs held valid training for GSE operation and possessed the necessary permits to drive on the airport apron.
Findings
- The primary cause of the incident was the incorrect positioning of the ground service equipment set (tractor and stairs).
- The placement of the equipment within the aircraft's ERA created an obstruction for the taxiing aircraft.