Summary
On July 30, 2008, at about 07:44 Japan Standard Time, a Boeing 777-200 registered VN-A146 operated by Vietnam Airlines as Flight HVN950 experienced a right engine fire warning while taxiing after landing at Narita International Airport. The flight originated from Ho Chi Minh Airport. The crew shut down the engine and activated the fire-extinguishing system, which silenced the alarm. After the aircraft arrived at the ramp and all 277 occupants disembarked, the right engine caught fire; the fire was extinguished by the firefighting squad. There were no injuries. The aircraft sustained minor damage.
Flight History
Flight HVN950 took off from Ho Chi Minh Airport at 02:11 JST. About three hours into the flight, while over Taipei at 37,000 ft, status messages "FIRE LOOP 2 ENG R" and "OVERHEAT CIRCUIT R2" appeared. The pilot in command noted the engine parameters were normal and cleared the messages. The aircraft landed on Runway 34R at Narita at 07:41. At 07:43:56, a message "R ENG OVHT CAUT" displayed. At 07:44:35, an "R ENG FIRE WARN" message appeared as the crew began the engine fire procedure.
Crew Actions
The crew shut down the right engine and discharged the fire extinguisher (bottle 2). The fire warning stopped. The pilot declared a MAYDAY and reported the fire. After coordination with air traffic control, the aircraft taxied to the ramp. At 07:52, the parking brake was engaged. All passengers and crew disembarked. Later, the right engine ignited and was extinguished by the firefighting squad.
Investigation Findings
The Japan Transport Safety Board investigated. Examination of the engine revealed that the O-ring on a hose connection in the engine fuel line junction box was broken. This finding was provided to the Civil Aviation Bureau on February 4, 2009. The investigation involved representatives from Vietnam and the United States.
Probable Cause
The probable cause, as stated by the investigation, was the broken O-ring on a hose connection in the engine fuel line junction box.