Incident Overview
On 18 August 2007 at 09:20 UTC, at Faro Airport (LPFR), a Boeing 757-300 (registration G-JMAB, MSN 32242) was parked on stand with engines shut down. A ramp operator, driving a motorized stair, approached the rear passenger door. Another operator was standing on top of the stair to assist with positioning and setting lateral platform guards.
When the operator attempted to brake, the brakes did not respond and the stair platform struck the aircraft fuselage in the area of the pressurization outflow valve. Inspection revealed indentations on the fuselage skin and the outflow valve was found unserviceable. The aircraft had to wait for the arrival and installation of a replacement valve before being ferried to its base for repair. No injuries were reported and damage to the aircraft was classified as light.
Investigation Findings
The operator had already positioned one stair at the front door before maneuvering this second stair to the rear door, suggesting he may have been under pressure to expedite passenger disembarkation. A ground handling personnel strike was in progress, affecting the working environment at the airport.
Although the operator stated that he approached the aircraft "slowly," the service supervisor described the impact as "very violent," and damage evidence supported that the vehicle speed was excessive for the location and maneuver, despite a slight negative slope in the ramp area.
When braking failed, the operator attempted to engage reverse gear, which is normally not possible while the vehicle is moving forward, instead of using the handbrake. He stated he was concerned for the safety of his colleague on the platform. However, any such maneuver would have caused a similar loss of balance for the second operator, which would have been negligible if the vehicle had been moving slowly as claimed.
Maintenance records for the stair showed that the last technical inspection was performed on 12 July 2006. No more recent records confirming any intervention on the braking system were presented. The operator who later removed the stair from the stand and drove it to the equipment parking area confirmed that the brakes were inoperative and used hand braking.
No procedures were referenced requiring verification of system operation before using the stairs. The operator stated that after starting the engine, he only waited long enough for the hydraulic system to pressurize. The operator's last training on equipment operation was on 3 March 2006.
Conclusions
The incident resulted from the operator of the passenger boarding stair not performing the required equipment checks before operation, driving at excessive speed for the location and situation, and failing to stop the stair due to a brake system malfunction of which he was not aware during driving. The stress he was under due to pressure for quick passenger service and the ongoing ground handling staff strike contributed to the omission of recommended equipment checks.
Probable Cause
The incident occurred because the step operator did not perform required equipment functional checks, drove at excessive speed, and could not stop the vehicle due to a brake system malfunction.