Singapore Airlines A330 Runway Excursion at Yangon Airport

Incident Overview and Aircraft Details On 21 May 2014 at approximately 0943 local time, an Airbus A330-300 operated by Singapore Airlines, registration 9V-STS, experienced a runway excursion while landing on Runway 21 at Yangon Airport, Myanmar. The aircraft was on a scheduled passenger flight from Singapore and carried 265 persons on board. It was powered by two Rolls-Royce Trent 700 engines. The occurrence was classified as a serious incident by the then Air Accident Investigation Bureau of Singapore, now the Transport Safety Investigation Bureau (TSIB), which conducted the investigation with the facilitation of Myanmar's Department of Civil Aviation (DCA). ## Approach and Landing Sequence The flight crew, consisting of a Captain as Pilot-in-Command (PIC), a Captain as Co-pilot, and a First Officer (FO) in an observer seat, was cleared for an Instrument Landing System (ILS) approach to Runway 21. During the descent, the crew observed passing showers and received weather updates indicating rain approaching the airfield and visibility reducing to 3,000 metres. The PIC manually flew the approach from 1,100 feet, using a crab technique to maintain alignment with the runway centreline despite a shifting left crosswind. At approximately 100 feet, the left crosswind speed dropped from 20 knots to 10 knots. The PIC reduced the crab angle and rolled the aircraft to the right to prevent a leftward deviation but over-corrected, causing the aircraft to drift right at about 50 feet. The Co-pilot and FO called out to go left, and the Co-pilot called for a go-around just before touchdown, but the PIC elected to land. The aircraft touched down to the right of the centreline, with the right main landing gear approximately 26 metres from the centreline. ## Excursion and Aftermath About one second after touchdown, the right main landing gear exited the paved runway surface. The PIC applied left rudder, and the crew manoeuvred the aircraft back onto the runway. The right main gear remained off the runway for approximately 600 metres, while the left main gear was off for about 300 metres. The aircraft stopped on the runway about 620 metres after re-entering the paved surface. Following the excursion, an ECAM message indicated a low green hydraulic reservoir. The crew performed the associated procedure and requested to be towed to the gate, which was accomplished. The green hydraulic system damage resulted in the loss of nose wheel steering capability. ## Damage and Injuries There were no injuries to the 265 persons on board. Aircraft damage included the green hydraulic system, innermost flap fairing canoes on both sides, the left engine's ingestion of mud and debris, gouging and cuts on several tyres, and deflation of Tyre No. 7. Some runway edge lights were also damaged. The shoulder surface adjacent to the runway was noted to be uneven and not flush with the runway pavement.