United Airlines Boeing 747-123 incident
Boeing 747-123 · Incident: airframe, component or system failure en route
From Los Angeles International Airport (LAX) to Narita International Airport (NRT)
Event
- NTSB case
- DCA88IA056
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Incident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Boeing 747-123
- Aircraft type
- Boeing 747
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N157UA
- Operator
- United Airlines
- Onboard fatalities
- Unknown
- Route
- From Los Angeles International Airport (LAX), Los Angeles, CATo Narita International Airport (NRT), Tokyo, JAPAN
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Fuel starvation
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Minor
Cause areas
- Flight engineer › Fuel system, improper use of
- Fluid, fuel › Starvation
- Pilot in command › Procedures/directives, improper
Not plotted · Location withheld: coordinates are missing, conflicting, invalid, or have no accepted acquisition method. No substitute location has been invented.
NTSB narrative
UNITED FLT 97 EXPERIENCED INDICATIONS OF UNEVEN FUEL FLOW FROM MAIN TANKS 2 AND 3 AT FL360 BEGINNING ABOUT 4- HOURS AFTER DEPARTURE ON AN 11-HOUR TRANSPACIFIC FLIGHT. THE FUEL SYSTEM HAD BEEN SET UP FOR ALL ENGINE FEED FROM THE NOS 2 AND 3 TANKS. ALTHOUGH IT WAS LATER ESTABLISHED THAT THE NUMBER 2 CROSSFEED VALVE FAILED IN THE CLOSED POSITION, THE S/O INFORMED THE CAPT THAT THE INTRANSIT LIGHT HAD ILLUMINATED WHEN THE VALVE SELECTOR WAS MOVED TO THE CLOSED POSITION - INDICATING NORMAL CROSSFEED VALVE OPERATION. FUEL SYSTEM PROBLEM WAS MISDIAGNOSED AS A PROBLEM OF FAULTY FUEL GAGE INDICATIONS. FUEL MONITORING INDICATED INSUFFICIENT FUEL FLOW FROM NO 2 TANK WHEN CROSSFEEDING. ENGS 1, 3, AND 4 FLAMED OUT WHEN FUEL WAS EXPENDED FROM ALL TANKS EXCEPT NO 2. EMERGENCY DESCENT WAS MADE TO DESTINATION TOKYO-NARITA AIRPORT. CREW REPORTED THEY USED FLAPS-20, BUT DFDR SHOWED FLAPS-1 WAS USED FOR LANDING. 3 TIRES BLEW ON LANDING. ALL 3 FLIGHTCREW QUALIFIED IN THE B-747 IN THE 13-MONTHS BEFORE THE INCIDENT.
Verbatim NTSB analysis from the NTSB dataset
Sources
NTSB record DCA88IA056
- Event ID
- 20001213X25661
- Case number
- DCA88IA056
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: d23c4e1a9eda17777dee82a080c264e5a3dbb4978185908b376796f6d78dad76; retrieved 2026-09-18T19:22:45.391Z.