Factual Information
On 3 October 2013 at 1122 hours, a Changi Tower controller (Controller 1) informed a maintenance vehicle with callsign Rover 39 of a bird carcass on Runway 02/20C. Rover 39 was instructed to proceed to Rapid Exit Taxiway (RET) E4. Controller 2, responsible for arriving aircraft, planned to permit five more landings before the vehicle would enter the runway.
At 1124 hours, Rover 39 reached the E4 holding point and reported its position. Controller 1 told the vehicle to wait three to four minutes. Controller 2 visually verified the vehicle’s presence at the holding point.
Sequence of Events
At 1125 hours, Controller 3, a supervisor unaware of the earlier coordination, contacted Rover 39 to expedite the bird removal. He instructed the vehicle to proceed for Runway 2 and prepare to enter. The co-worker of the driver acknowledged with “thank you.” Controller 3 did not request a full readback.
Rover 39 moved off at 1125:43 hours and entered the runway at 1126:01 hours, despite red stop bar lights being illuminated. The vehicle stopped on the eastern edge between RETs E4 and E5.
Meanwhile, at 1126:09 hours, Controller 2 cleared a Boeing 777-312ER (registration 9V-SWG) for landing on Runway 20C. Controller 2 had scanned the runway visually but did not notice Rover 39. The A-SMGCS generated warnings, but the controllers did not perceive them.
The aircraft touched down at 1126:47 hours. The flight crew sighted the vehicle when the aircraft decelerated to about 100 knots. The pilot flying disconnected auto-braking and applied manual braking; the pilot-in-command manoeuvered slightly right to increase separation. At 1126:58 hours, Controller 4 instructed Rover 39 to vacate. The aircraft’s left wing passed over the vehicle as it moved away. Both vacated the runway safely.
Personnel Information
The vehicle contained a driver (holding a Category 1 Airfield Driving Permit) and a co-worker (without such permit). Air traffic controllers held valid licences.
Meteorological Information
Weather was clear with good visibility.
Conclusion
The AAIB classified this as a serious incident. The runway incursion was caused by the unauthorised entry of Rover 39 onto the runway.