Overview
• Operator: All Nippon Airways (ANA)
• Aircraft Model: Boeing 787-10
• Registration: JA901A
• Flight Number: NH-892
• Route: Ho Chi Minh City (Vietnam) → Tokyo Haneda (Japan)
• Date: 5 February 2025
• Occupants: 244 passengers, 11 crew
• Nature of Incident: Engine oil quantity warning
Incident Summary
All Nippon Airways flight NH-892, operated by a Boeing 787-10 (JA901A), was en route from Ho Chi Minh City (Vietnam) to Tokyo Haneda (Japan) when the crew received a low oil quantity indication for one of the aircraft’s Rolls-Royce Trent 1000 engines. The aircraft was at FL370, approximately 60 nautical miles northeast of Naha (Japan), when the decision was made to divert for a precautionary landing.
The aircraft landed safely on runway 36L at Naha Airport approximately 35 minutes after the diversion was initiated. Emergency services were on standby, but no further issues were reported.
The remainder of the flight was cancelled, and passengers were rebooked on seven domestic flights to reach their final destination in Tokyo.
Sequence of Events
Cruise Phase
• The aircraft was cruising at FL370 when the low engine oil quantity warning appeared for the right-hand Rolls-Royce Trent 1000 engine.
• The crew assessed the situation and decided to divert to Naha as a precautionary measure.
Diversion & Landing
• The aircraft turned around and commenced descent towards Naha Airport.
• No abnormal engine behavior (such as high temperatures or vibration warnings) was reported.
• The aircraft landed safely on Naha’s runway 36L approximately 35 minutes after the decision to divert.
• The aircraft taxied to the gate without requiring emergency assistance.
Aftermath
• The flight was cancelled, and passengers were rebooked on alternate ANA domestic flights to Haneda.
• The aircraft remained on the ground for about 38.5 hours before repositioning to Tokyo.
Analysis & Possible Causes
1. Engine Oil Quantity Anomaly
• The Rolls-Royce Trent 1000 engine has a history of durability issues, including premature wear and oil system concerns.
• Possible causes for a low oil quantity indication:
• Actual oil loss due to a minor leak within the lubrication system.
• Sensor malfunction, leading to a false warning.
• Oil system degradation, such as seal wear or oil consumption exceeding normal parameters.
2. Precautionary Diversion Decision
• A low oil quantity warning does not necessarily indicate an immediate engine failure, but prolonged operation under such conditions could lead to oil starvation, overheating, or mechanical failure.
• The crew made a conservative decision to land at the nearest suitable airport rather than risking continued flight to Tokyo.
3. Engine Reliability Concerns
• The Trent 1000 engine family has had several issues in recent years, including oil-related failures and durability concerns.
• If this issue is linked to ongoing Trent 1000 performance challenges, further maintenance action or fleet-wide inspections may be required.
Preventative Measures & Safety Recommendations
• Post-flight maintenance should include a detailed inspection of the oil system to determine if there was an actual oil leak or a faulty sensor reading.
• Trend monitoring on ANA’s 787-10 fleet should be intensified, especially on Trent 1000-powered aircraft, to detect early signs of oil system wear or degradation.
• If the issue is found to be a systemic problem, Rolls-Royce and ANA should consider engine modifications or increased maintenance intervals.
Aircraft Status & Operational Impact
• The affected aircraft remained in Naha for approximately 38.5 hours before positioning back to Tokyo.
• The flight was cancelled, and passengers were accommodated on alternative ANA flights.
Disclaimer
This report is based on available information as of 10 February 2025. While every effort has been made to ensure accuracy, the completeness of the details cannot be guaranteed. If you are the rightful owner of any referenced materials and wish them removed, please email takedown@cockpitking.com.
