Description

On 30 May 2007, at about 0555 hours local time, the crew of an Airbus A340-300 had to apply TOGA (Take-off Go Around) power and rotate abruptly at a high rate to become airborne while taking off from Runway 20C at Singapore Changi Airport, when they noticed the centreline lights were indicating the impending end of the available runway. The crew had calculated the take-off performance based on the full TORA (Take-off Run Available) of 4,000 m because they were unaware of the temporary shortening of Runway 20C to 2,500 m due to resurfacing works.

The Investigation

An Investigation into this Serious Incident was carried out by the Singapore AAIB. This found that the Airport Operator risk assessment had identified risk scenarios associated with the work in progress on Runway 20C which included that pilots may think that the runway was still operating at 4,000m or that an aircraft may overrun the shortened runway into the runway resurfacing work area. To mitigate these hazards, the airport operator:

• established a 500 m safety zone between the temporary runway end and the start of the work area
• placed marker boards with red lights at 260 m from the temporary runway end to demarcate the boundaries of the closed runway
• installed runway end lights at the temporary runway end
• deactivated all airfield lights in the closed section of runway including PAPI, runway centreline and runway edge lights
• changed the distance-coded lighting configuration for the runway centreline lights and runway edge lights to correspond to the reduced TORA actually available
• covered guidance signs within the runway closed area
• replaced guidance signs showing runway distance available
• installed a runway information guidance sign “Shortened Runway”
• installed taxiway edge lights across the runway at access ‘E7’ indicating it as the last runway exit taxiway for the part of Runway 20C in use.

The Investigation concluded that the ‘Significant Factors’ which led to the occurrence were:

• The information on the shortening of Runway 20C was not incorporated into Gulf Air’s Far East NOTAM and that the Gulf Air NOTAM system was not robust enough to ensure that important information was not missed.
• The flight crew listened to the Automatic Terminal Information Service (ATIS) during their pre-flight preparation but did not then check it subsequently any updates, thus missing the information on the shortening of Runway 20C.
• After becoming aware that the flight crew did not have the latest ATIS information, the ATCO did not positively identify to them the latest ATIS edition status. The ATCO also did not attempt to revert to the flight crew to ensure that they had the updated ATIS information.
• The First Officer did not check the ATIS again even though he told the ATCO he would do so when seeking clearance from Clearance Delivery.
• The guidance signs pertaining to the shortened Runway 20C positioned along the taxi route to the runway failed to draw the attention of the flight crew to its information.

During the course of the Investigation, various corrective actions were taken by both Gulf Air and Singapore ATC.

The Full Report of the Singapore AAIB published on 15 December 2008, made three Safety Recommendations:

1. The airport operator review the way important information is indicated on movement area guidance signs concerning any temporary runway length changes so that the signs can be effective in drawing flight crews’ attention.
2. The airline review its procedure and training of the pilots to improve flight crews’ awareness of movement area guidance signs around airports.
3. The airline require its flight crews to report any significant incident which they are aware of to the local air traffic control unit.

Further Reading

• The Investigation into a similar serious incident at Manchester UK in 2003
• The Investigation into a similar serious incident at B773, Auckland Airport New Zealand, 2007