Unfallbericht:United flight 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 captain 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 gauge indications. Fuel monitoring indicated insufficient fuel flow from no 2 tank when crossfeeding. Engines 1, 3, and 4 flamed out when fuel was expended from all tanks except no 2. An emergency descent was made to destination Tokyo-Narita airport. The crew reported they used flaps-20, but DFDR showed flaps-1 was used for landing. Three tires blew on landing. All 3 flightcrew were qualified in the B747 in the 13-months before the incident.
|Datum:||02 MAI 1988|
|Fluggesellschaft:||United Air Lines|
|Baujahr:|| 1970-09-24 (17 years 8 months)|
|Besatzung:||Todesopfer: 0 / Insassen: 19|
|Fluggäste:||Todesopfer: 0 / Insassen: 239|
|Gesamt:||Todesopfer: 0 / Insassen: 258 |
|Unfallort:||nahe Tokyo (Japan)
|Flugphase:|| Während des Fluges (ENR)|
|Flug von:||Los Angeles International Airport, CA (LAX/KLAX), USA|
|Flug nach:||Tokyo-Narita Airport (NRT/RJAA), Japan|
PROBABLE CAUSE: "fluid,fuel..starvation / fuel system..improper use of..flight engineer / procedures/directives..improper..pilot in command."
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not
display the exact flight path.
Distance from Los Angeles International Airport, CA to Tokyo-Narita Airport as the crow flies is 8696 km (5435 miles).
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.