What happened
On 29 February 2004, a Boeing 737-8AS, registration EI-CSF, was operating a public transport flight from Oslo to London (Stansted) Airport. At approximately 22:30 UTC, the aircraft was taxiing along Taxiway Juliet and turned left into Stand 65L. The commander utilized the Azimuth Guidance Nose In Stand (AGNIS) system to guide the aircraft into its position.
Following the engine shutdown and the disembarkation of all 136 passengers and 6 crew members, the pilot was informed that the aircraft's left wing had struck a set of mobile steps. The crew reported that no impact was felt during the taxiing maneuver. The contact resulted in a hole in the outboard leading edge of the left wing, though there were no injuries to anyone on board.
The investigation
Investigators examined the positioning of the mobile steps and the lighting conditions at the time of the incident. It was determined that the steps had been parked on the left side of the stand, with their wheels positioned outside the designated markings. However, the body of the steps and the right-side safety handrail, which remained in the extended position, protruded into the stand area.
At the time of the incident, the operation was taking place at night. While visibility was considered good and the stand was illuminated, the investigators noted that the handrail and the upper portion of the steps might have been obscured from the commander's view. This difficulty was compounded by the fact that a light source was positioned directly behind the steps relative to the aircraft's approach.
Findings
- The primary cause of the incident was the encroachment of the mobile steps into the stand area.
- The safety handrail of the steps was left in an extended position, creating an obstruction.
- The AGNIS system usage implies an assumption by the commander that ground staff had verified the stand was clear and safe for entry.
- Nighttime lighting conditions and the positioning of a light behind the obstacle likely contributed to the lack of visibility of the handrail.