What happened
On August 23, 2015, at approximately 20:50 UTC, a ground service incident occurred at Lisbon Airport on the west side of platform 70. A Rofan ZH-4 tractor, operated by GroundForce, was maneuvering through the designated lane to provide assistance to an ATR 42 aircraft parked at stand 701.
In an attempt to approach the front cargo hold of the ATR 42 while avoiding other personnel and equipment positioned near the ATR 42's tail, the tractor operator initiated a left turn toward stand 702. During this maneuver, the operator failed to notice a Falcon 7X, registration VQ-BGG, which was parked at stand 702. The tractor, traveling only 11 meters from the stand's lead-in line, struck the trailing edge of the Falcon 7X's right wing.
The investigation
The GPIAAF investigation established that the impact was violent enough to cause substantial damage to the Falcon 7X. Specifically, the front pillars of the tractor's frame tore the aileron on the right wing. Because the aircraft's parking brake was disengaged, although the nose gear remained chocked, the force of the collision caused the aircraft to undergo violent torsion along its fuselage axis. The impact resulted in the aircraft being displaced approximately 10 meters from its lead-in line, ending in a position roughly 80 degrees twisted relative to its longitudinal axis.
Investigators found no evidence on the pavement of any braking or steering corrections attempted by the tractor operator prior to the collision. It was also noted that the pavement was wet due to recent rainfall.
Findings
- The primary cause of the collision was the tractor operator's failure to recognize the presence of the parked aircraft during a turn.
- The impact caused significant structural damage, including tears to the right wing aileron.
- The aircraft's displacement from the stand was facilitated by the fact that the parking brake was not engaged at the time of the incident.
- Environmental conditions, specifically wet pavement from previous rain, were present at the time of the event.
- The tractor operator was not wearing a seat belt during the collision and required medical evaluation at a hospital following the incident.