Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 250; Flight Crew Total 21000; Flight Crew Type 8500
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Aircraft; Human Factors
On six to eight mile final in VFR conditions for Runway 34L at Tokyo Narita an EICAS FLAPS PRIMARY FLAPS appeared. This occurred when flaps 20 was selected for reducing to target speed in compliance with the 10 DME 160 KTS speed to 4.8 DME then reduce to target speed restriction. The aircraft at the time was at 160 KTS and landing gear was down. The flaps fully extended to flaps 20 and the airplane was fully stabilized. I was the pilot flying and was hand flying at the time. The Captain and other First Officer worked the problem and we jointly determined it was prudent; desirable; and safe to continue to land rather than go-around since we were fully stabilized and there were no other issues to address with Maintenance or Dispatch. Landing conditions were ideal and 34L is very long runway. Since we were at flaps 20 the VREF was changed to 20 REF and we added 5 KTS to the target speed and reduced to that speed (auto-throttles were on). The 500 FT call was made and we verified flaps 20. We did however forget to select the GPWS for Flap Override Switch and we did receive the aural warning. It was quickly selected and we landed without incident.After landing we contacted Dispatch on SATCOM to advise him of the incident. I agree with the Captain and our crew decision to continue the approach as we were ahead of the airplane and fully stabilized. If there was any doubt in our minds there would have been no hesitation to go-around especially when IMC; behind the airplane; on a shorter runway; or at an unfamiliar airport. In retrospect I could have briefly reengaged the autopilot and perhaps caught the flap override switch omission; but that too could have been only for a brief time before having to disengage it for the landing. Exercising Captain's emergency authority was addressed but it we felt that this not rise to that standard nor was it necessary.
[Narrative 2 has no additional information]
An air carrier First Officer and Relief Pilot reported that they experienced an EICAS FLAPS PRIMARY message on final approach to RJAA. They decided since they were stabilized and familiar with the airport and the long runway they were okay to continue with the landing.