On 23 September 1999, at about 2247 local time, a Qantas Boeing 747-438 aircraft registered VH-OJH (callsign Qantas One) overran runway 21 Left (21L) while landing at Bangkok International Airport, Thailand.
The overrun occurred after the aircraft landed long and aquaplaned on a runway which was affected by water following very heavy rain.
The aircraft sustained substantial damage during the overrun. None of the three flight crew, 16 cabin crew or 391 passengers reported any serious injuries.
When the aircraft was approximately 10 ft above the runway, the captain instructed the first officer to go around.
As the first officer advanced the engine thrust levers, the aircraft’s main wheels touched down (1,002 m along the 3,150 m runway, 636 m beyond the ideal touchdown point).
The captain immediately cancelled the go-around by retarding the thrust levers, without announcing his actions.
Those events resulted in confusion amongst the other pilots, and contributed to the crew not selecting (or noticing the absence of) reverse thrust during the landing roll.
Due to a variety of factors associated with the cancellation of the go-around, the aircraft’s speed did not decrease below the touchdown speed (154 kts) until the aircraft was 1,625 m or halfway down the runway.
Qantas flight QF1 crossed the runway threshold 20 kts above VREF and 32 ft above the ideal threshold crossing height
Parts 1 to 4 identified several unsafe acts and active failures that had a significant influence on the development of the accident. These were:
- The flight crew did not use an adequate risk management strategy for the approach and landing.
- The first officer did not fly the aircraft accurately during final approach.
- The captain cancelled the go-around decision by retarding the thrust levers.
- The flight crew did not select (or notice the absence of) idle reverse thrust.
- The flight crew did not select (or notice the absence of) full reverse thrust.
- The flight crew did not consider all relevant issues when deciding not to conduct an immediate evacuation.
- Some crewmembers did not communicate important information during the emergency period.
Other significant active failures were:
- The runway surface was affected by water.
- The cabin interphone and passenger address system became inoperable.