What happened
On the night of 12 November 1998, a Gulfstream G-IV, registration VP-BHG, was performing a private flight from Pontoise Airport, France, to London Stansted Airport. The flight was the final leg of an evening itinerary that had included a stop at Paris Le Bourget. The crew, consisting of a commander, a first officer, and a licensed ground engineer, arrived at Stansted at 2356 hrs.
During the approach, the crew received ATIS information regarding ongoing runway maintenance. The information included a specific warning that the green threshold bar should not be used as a touchdown point and that pilots must use a 3.5° approach angle via temporary APAPI units. The crew discussed the warning and interpreted the instruction to mean they should avoid landing at the end of the runway marked by green lights.
As the aircraft approached Runway 23, the commander transitioned to a visual approach. The pilot targeted a touchdown point alongside red "wing bars" located on the runway. During the landing, the aircraft overflew runway end cones and came to a stop 100 metres before the threshold of Runway 05. While the aircraft was moving along the runway at a high speed, the tower controller issued commands to stop and hold position. The crew, believing they were still airborne, did not realize they had landed on a closed section of the runway until notified by Air Traffic Control several minutes later. There were no injuries and no damage to the aircraft.
The investigation
The investigation examined the maintenance schedule at Stansted, which involved a phased closure of the runway. At the time of the incident, the airport was in phase two of the project, which closed the south-western half of the runway. The investigation reviewed the lighting configuration, which included approach lights, threshold greens, and the red wing bars.
Investigators found that the crew's mental model of the airfield was influenced by a successful landing on the first phase of the maintenance two nights prior. The investigation also looked at the visual cues available to the pilot, noting that the commander identified the red wing bars as the primary landing reference and that the approach path was measured at 3° rather than the required 3.5°.
Findings
- The crew misinterpreted the ATIS warning regarding the green threshold bar, leading them to believe the end of the runway was unavailable.
- The pilot misidentified the red "wing bars" as the primary landing reference.
- The approach angle flown was approximately 3°, failing to meet the required 3.5° standard.
- The crew's reliance on visual cues led to the landing on a closed segment of the runway.
- The presence of dimmed runway edge lights from the closed section may have contributed to the pilot's perception of the runway's extent.