B747-400
Flight Crew Air Transport Pilot (ATP)
Troubleshooting
Aircraft Equipment Problem Less Severe
Flight Crew Overcame Equipment Problem
Aircraft
Crew composite was I and a First Officer that I had been with for the previous 12 days. We were meeting our Relief First Officer in Hong Kong. We all experienced slight delays in getting to the airport which I identified as a distraction to our flight. We all were properly rested; some of us slept better than others; but I did deem we were all fit for duty. During our cockpit setup; I took a moment to speak to both First Officers about the known and any potentially unknown threats. I made special note to turn to my First Officer who was now acting as Relief Pilot. I directed him to be very candid and direct at anything that he observed that was not correct or he had questions about. Weather conditions were rain showers with a wet runway; winds were slightly gusty. Takeoff weight was approximately 820;000 LBS. My First Officer was in need of takeoffs and landings for currency; for which I chose to; give him this leg. We were cleared for takeoff; final check complete; and TOGA power selected with all proper FMA's displayed. At approximately 400 FT; I felt a deceleration and the aircraft began to pitch over. Simultaneously; the Relief Pilot called out 'something is not right.' The First Officer continued to manually fly and flight level change was selected. The airspeed was manually increased through the cleanup portion of the flight. We all stayed focused on aircraft control until approximately 7;000 FT when the autopilot was engaged. Not fully understanding what had happened; the Relief Pilot said all the performance data dropped out for reasons unknown. With no immediate concerns; I elected to continue a normal climb until reaching cruise altitude. We; as a crew; tried to understand what had happened. I requested that both First Officers discuss the FMC issues while I monitor the flight. With no clear apparent reason for what had happened; we as a crew discussed our options as to whether to continue to destination or to divert. During this time; aircraft control was transferred back to the First Officer while I worked with the Relief Pilot to determine what was working and not working on the jet. Prior to calling Dispatch; we as a crew all agreed that we had identified all potential threats and a mitigation strategy to trap any unforeseen errors. An hour after takeoff still south of Japan; I directed the First Officer to handle ATC communications and to monitor the aircraft; while the Relief Pilot and I contacted Dispatch. Upon initial contact; I stated that this was not an emergency but was requesting the assistance of my Dispatcher; and the manager on duty. The conversation continued with all parties regarding the continuation of this flight to destination. I informed everyone of the status of this aircraft-- that the performance functions of both FMC's were inoperative and no longer providing our fuel prediction or altitude capability. Prior to contacting Dispatch; we had clearly established a navigation accuracy check and both navigation platforms were accurate. Additionally; we went through the flight plan and verified its accuracy and fuel predictions for each waypoint and the destination. Based on the status of my aircraft; and complete concurrence with my crew; I asked Dispatch if they could think of any reason that we could not continue the flight safely to destination based on our plan of action. All parties agreed and I announced my decision as the Captain; to continue the flight to destination. The remainder of the flight was uneventful.
As Relief Pilot on a LNAV/VNAV takeoff from VHHH passing through approximately 400 FT radar altitude I noticed that the pitch FMA on flying pilot's PFD (First Officer) incorrectly displayed VNAV ALT instead of VNAV SPD; I immediately looked at the MCP alt window and verified that our initial assigned alt of 5;000 FT was displayed. I then referenced the pilot not flying CDU to check legs page for altitude information and observed that all performance data was missing. I then notified the pilot flying that something was wrong with VNAV and recommended calling for a different pitch mode. The pilot flying was hand flying with FD in LNAV and pitch mode in FLCH. I then noticed that our speed was well above flaps 10 speed and also suggested to pilot not flying to manually set speeds for flap cleanup. After flap cleanup I noticed that the ACARS displayed a 'wind upload rejected due to VNAV in descent mode' message. During climb out to FL290; the VNAV climb page and cruise page had no altitude or performance data displayed. We also noticed that the VNAV descent page was active. Data on the PERF page was verified to be correctly entered. After discussing the best way to correct the situation; the initial cruise altitude assigned was manually entered in the climb page and VNAV was reengaged. Level at initial cruise alt; all navigation checks were completed and verified to be operating correctly; winds were correctly displayed on RTE data page; VNAV Cruise page was active; and VNAV PTH displayed correctly. However; landing fuel quantity was blank on progress page. After consulting with our Dispatcher; the Captain made the decision to continue the flight verifying flight plan fuel and actual fuel at each way point.
B747-400 flight crew describes an FMC anomaly shortly after takeoff resulting in a thrust reduction and loss of all FMC performance data. After some discussion and manual entries the Captain elects to continue to destination.