Narrative:

The flying first officer and I were on our break in the bunks. I was awakened early and the bunkies explained that we had had a dual FMC failure. They had gone through all the flight manual procedures and had discussed the situation with both dispatch and maintenance control. We were operating in standby navigation; with legs; navigation/radar; and progress pages available on the cdus; and normal autopilot operation; with no autothrottles. They had gotten re-dispatched and ZZZ weather was forecast to be 1 mile upon our arrival. The dispatcher told them he would pass along the FMC failure information to the ATC coordinator. We went over everything we could think of to prepare for arrival; and expected to land on runway 10. Center told us to expect holding unless we could accept runway 9R; with braking action fair. I declined and said we'd need runway 10 or runway 28; which was closed right then for snow removal. ZZZ almost always expects us to accept runway 9R or runway 27L; and I've even been given runway 27R; so all the rjs coming in from the south and east can land on runway 28! We never did hold; getting vectors from ZZZ1 approach and the ZZZ approach; and we were about the third aircraft for runway 28; where the braking was reported to be good. On the ILS; approach asked if we would be able to 'stop on the runway.' I answered in the affirmative. When we landed and turned off onto taxiway T; tower asked if the 'emergency' was over and if we still needed assistance. I noticed all the crash fire rescue equipment on the taxiways. Someone had declared an emergency; I guess either dispatch or ATC. No one told us; though; and we had not. Maybe dispatch declared minimum fuel and overreacted. By the way; we landed with fuel of about 28.0; or somewhere in that area. The 3 first officers did an outstanding job -- especially the bunkies; who had to go through all kinds of procedures and radio work. They said dispatch and maintenance control were extremely helpful; so my thanks to them also.

Google
 

Original NASA ASRS Text

Title: A B747-400 experienced dual FMC failures. The air carrier declared an emergency because of poor destination weather and runway conditions. The crew was able to navigate and fly the approach without problems.

Narrative: The flying First Officer and I were on our break in the bunks. I was awakened early and the bunkies explained that we had had a dual FMC failure. They had gone through all the flight manual procedures and had discussed the situation with both Dispatch and Maintenance Control. We were operating in Standby Navigation; with Legs; Navigation/Radar; and progress pages available on the CDUs; and normal autopilot operation; with no autothrottles. They had gotten re-dispatched and ZZZ weather was forecast to be 1 mile upon our arrival. The Dispatcher told them he would pass along the FMC failure information to the ATC Coordinator. We went over everything we could think of to prepare for arrival; and expected to land on Runway 10. Center told us to expect holding unless we could accept Runway 9R; with braking action fair. I declined and said we'd need Runway 10 or Runway 28; which was closed right then for snow removal. ZZZ almost always expects us to accept Runway 9R or Runway 27L; and I've even been given Runway 27R; so all the RJs coming in from the south and east can land on Runway 28! We never did hold; getting vectors from ZZZ1 Approach and the ZZZ Approach; and we were about the third aircraft for Runway 28; where the braking was reported to be good. On the ILS; Approach asked if we would be able to 'stop on the runway.' I answered in the affirmative. When we landed and turned off onto Taxiway T; Tower asked if the 'emergency' was over and if we still needed assistance. I noticed all the Crash Fire Rescue equipment on the taxiways. Someone had declared an emergency; I guess either Dispatch or ATC. No one told us; though; and we had not. Maybe Dispatch declared minimum fuel and overreacted. By the way; we landed with fuel of about 28.0; or somewhere in that area. The 3 First Officers did an outstanding job -- especially the bunkies; who had to go through all kinds of procedures and radio work. They said Dispatch and Maintenance Control were extremely helpful; so my thanks to them also.

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.