When their fuel temperature dropped below the minimum allowable a B767-300 flight crew had to declar...

Narrative:

At cruise altitude approximately two hours from rjaa our fuel temperature was at or below minimum temperature. Fom was consulted to verify minimum temperature. QRH procedures were accomplished. Using cpdlc we contacted ATC to ask for lower altitude and a speed increase. We were at 36;000 ft. ATC cleared us for a speed increase but was only able to approve descent to 35;000 ft due to traffic 10 miles ahead at 34;000 ft. We checked the fuel temperature at the lower altitude but there was no increase. With all normal options exhausted; we called the captain to the flight deck from his break and briefed him. We then contacted dispatch and maintenance control via satcom and; after discussion; decided to declare an emergency in order to descend to a lower altitude. We declared the emergency with ATC and; while employing track diversion procedures; descended to 26;000 ft. Messages to ATC and company were relayed so all parties were on same page. When in radar contact; we worked with tokyo control. Fuel temperature came above minimums after approximately 30 minutes at 26;000 ft and we were cleared back flight plan route to rjaa.

Original NASA ASRS Text

Title: When their fuel temperature dropped below the minimum allowable a B767-300 Flight Crew had to declare an emergency in order to descend to a lower/warmer altitude over the Pacific in route to RJAA. Over a period of time the fuel temperature increased to within limits.

Narrative: At cruise altitude approximately two hours from RJAA our fuel temperature was at or below minimum temperature. FOM was consulted to verify minimum temperature. QRH procedures were accomplished. Using CPDLC we contacted ATC to ask for lower altitude and a speed increase. We were at 36;000 Ft. ATC cleared us for a speed increase but was only able to approve descent to 35;000 Ft due to traffic 10 miles ahead at 34;000 Ft. We checked the fuel temperature at the lower altitude but there was no increase. With all normal options exhausted; we called the Captain to the flight deck from his break and briefed him. We then contacted Dispatch and Maintenance Control via SATCOM and; after discussion; decided to declare an emergency in order to descend to a lower altitude. We declared the emergency with ATC and; while employing track diversion procedures; descended to 26;000 Ft. Messages to ATC and company were relayed so all parties were on same page. When in radar contact; we worked with Tokyo control. Fuel temperature came above minimums after approximately 30 minutes at 26;000 Ft and we were cleared back flight plan route to RJAA.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	986506
Time
Date	201112
Local Time Of Day	1201-1800
Place
Locale Reference	ZOA.ARTCC
State Reference	CA
Aircraft 1
Make Model Name	B767-300 and 300 ER
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Oceanic
Flight Plan	IFR
Person 1
Function	Relief Pilot Pilot Not Flying First Officer
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Flight Engineer
Experience	Flight Crew Last 90 Days 120 Flight Crew Total 23000 Flight Crew Type 8000
Events
Anomaly	Aircraft Equipment Problem Less Severe

When their fuel temperature dropped below the minimum allowable a B767-300 flight crew had to declare an emergency in order to descend to a lower/warmer altitude over the pacific in route to rjaa. Over a period of time the fuel temperature increased to within limits.