On 28 February 2002, ARROW AIR flight APWP6L touched down on Runway 02L at Singapore Changi Airport at 0029 hours. The runway controller at Changi Tower instructed the aircraft to park at Bay 117, a remote aircraft parking bay.
The ground movement planner at Changi Tower selected the taxiway centre line lights to guide the aircraft along Taxiway WA to Bay C7 (Bay 117 is the second parking bay after Bay C7).
Instead of stopping at the end of its assigned taxi route, the ARROW AIR flight APWP6L continued taxiing past Bay C7 along a diverted portion of Taxiway WA. At about 0037 hours, the aircraft called Changi Tower to indicate its position near Bay 106.
Realising that the ARROW AIR flight APWP6L had missed its assigned parking position, the ground movement planner at Changi Tower reselected the taxiway centre line lights to guide the aircraft back to Bay 117.
The aircraft followed the return route until it was abeam Bay 117 on the straight section of the diverted portion of Taxiway WA.
At that location, the pilot saw the ground marshaller in position at Bay 117 on the aircraft’s right side. Instead of continuing to follow the taxiway centre line lights on the assigned taxi route, the aircraft turned right. In doing so, it left the Taxiway WA centre line and went onto a grass area between Taxiway WA and the parking apron.
The nose gear of the aircraft went across a drain within the grass area. The aircraft came to a halt when its main landing gears went into the drain at about 0044 hours.
– The accident took place at night in clear weather.
– The flight crew members were properly licensed, qualified, medically fit, and in compliance with flight and duty time regulations
– The flight crew had the latest revision of the Jeppesen charts showing the layout of Singapore Changi Airport, including the yellow supplementary chart showing the area near Bay 117 in greater detail.
– The flight crew was not familiar with the Terminal 1 West Apron area where Bay 117 was located.
– The flight crew was aware of the NOTAM tow-in requirement at Bay 117 during hours of darkness.
– The Apron Control duty supervisor was aware of the requirement for aircraft to be towed into Bay 117. He did not coordinate with ATC and the ground handler on towing arrangements as there was no towing procedure established for aircraft assigned to Bay 117 or 118.
– The runway controller was not aware of the requirement for aircraft to be towed into Bay 117. He instructed ARROW AIR flight APWP6L to follow the green lights to Bay 117 in accordance with standard ATC procedures.
– The flight crew did not stop at Bay C7 to ask for instructions or guidance to get to Bay 117.
– After missing Bay 117 initially, the flight crew continued taxiing in search of the bay on their own
– On the subsequent return towards Terminal 1 West Apron, after sighting Bay 117 and the marshaller on the right of the aircraft, the flight crew deviated from the Taxiway WA centre line marking and green centre line lights and turned the aircraft to the right directly towards Bay 117.
– The flight crew did not see a turn signal from the marshaller but believed they saw the marshaller waving a “move ahead” signal.
– The flight crew did not notice on the Jeppesen charts that there was a turf island separating Taxiway WA from the parking apron where Bay 117 was located.
– The flight crew turned right from the straight section of the diverted portion of Taxiway WA to head directly towards Bay 117 even though there was no turn signal from the marshaller, no instruction to turn from ATC and no aircraft parking bay guidance marking on the ground to indicate to the flight crew to turn right
– The landing lights of the aircraft were turned on.
– As taxiway centre line lights were provided along Taxiway WA, according to ICAO Annex 14, there was no requirement for taxiway edge lights to be provided. However, where there is a large unmarked paved area adjacent to a taxiway, the provision of taxiway edge lights or reflective markers (in addition to taxiway centre line lights) would provide an additional cue to pilots to stay within the taxiway. This may help to prevent pilots inadvertently straying off the taxiway.
– There were no edge lights or markers to show the grass area between Taxiway WA and the parking apron where Bay 117 was located. There is no requirement in ICAO Annex 14 for edge lights or markers to show the presence of grass areas adjacent to taxiways.
– The drain located within the grass area between the diverted portion of Taxiway WA and the parking apron was outside the taxiway strip. According to ICAO Annex 14, drains located outside a taxiway strip are not required to be covered.
– The airworthiness of the aircraft was not a factor in this accident.