What happened
On 27 April 2008, an Airbus A340-313, registration G-VAIR, was conducting a commercial passenger flight from London Heathrow to Nairobi. During the approach to Runway 06, air traffic control informed the crew that a preceding aircraft had reported low landing visibility, specifically a cloudbase of 300 ft and a visibility of 3,000 m.
The crew performed an RNAV approach using autopilot and autothrottle. While the pilots initially maintained visual contact with the runway lights between 300 ft and 200 ft, the aircraft entered a patch of fog after touchdown. As the aircraft floated at approximately 20 ft, the pilot flying lost sight of the right side of the runway and the runway lights. The commander also lost visual contact with the right edge of the runway.
Upon realizing the aircraft was drifting, the commander initiated a go-around. The crew advanced the thrust levers to full power, and the aircraft became airborne again after being on the ground for less than five seconds. During the maneuver, the aircraft's left main gear left the paved surface, causing minor damage to the lower fuselage and destroying one runway edge light.
The investigation
The AAIB investigation, conducted alongside Kenyan authorities and the French BEA, examined the aircraft's flight recorders and runway conditions. Investigators identified ground marks starting 800 m from the runway threshold. These marks indicated that the left main gear traveled 160 m along the runway before striking a light and then continuing 180 m parallel to the runway off the paved surface.
Technical inspections of G-VAIR revealed minor scratches to the left aft lower fuselage and mud spray on the fuselage and horizontal stabilizer. The investigation also reviewed the runway's infrastructure, noting that the edge lighting was positioned 7.5 m from the paved edge, which deviates from ICAO standards.
Findings
- The crew experienced a loss of visual references due to fog during the landing flare.
- The touchdown zone of Runway 06 was heavily contaminated with rubber deposits, which may have reduced braking effectiveness.
- There was a discrepancy between the visibility reported by the automated weather system (550 m RVR) and the information provided to the crew during the approach.
- The runway edge lighting was located further from the paved surface than recommended by ICAO Annex 14.