B777-200
Flight Crew Air Transport Pilot (ATP)
Time Pressure; Situational Awareness; Training / Qualification
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft; Airspace Structure; Environment - Non Weather Related; Procedure
Landing south in ZZZ; ATC near capacity; busy night. Given a number of speed assignments during our arrival; and we had slowed to 210 kts by 40 NM from field. On base leg to final; Runway XXL; we were assigned 160 kts. Our ZFW of 505;000 lbs required 30 flaps to go below 165 kts; so we asked to stay at 165 and were cleared for that; initially. On dogleg to final; still approximately 20 miles to touchdown; we were assigned 160 kts to 5 NM final. Lowered the gear and as we selected 30 flaps we got an EICAS alert 'PRIMARY FLAPS FAIL'. We ran the non-normal checklist and noted that the flaps were extending beyond 25 as we read the checklist. By the time we finished the checklist; we were configured with gear down and flaps 30; with field in sight and intercepting the glideslope. All indications for the approach were normal; autopilot was engaged and the aircraft was stabilized. As Pilot Monitoring; I made the decision to continue the approach as I considered it a safer course of action than discontinuing approach at that point; especially since we were on final. I elected also to leave the flaps at 30 instead of trying to raise them to 20 at that point; confident that the aircraft in that configuration had more than enough go-around performance. FO was pilot flying and continued the stabilized approach to an uneventful landing.Submitting this report because after completing the 'Primary Flaps Fail' checklist; I determined it safer to remain in current; stabilized configuration for landing than to try and raise the flaps via alternate means to the recommended configuration of flaps 20. Weather was clear and we were confident that the aircraft had more than sufficient go-around capability.Our option was to discontinue the approach; request vectors and reset the flaps from 30 to 20. With the traffic load on approach; we determined it safer to continue to landing. I don't think this type of event can be prevented; as it was an aircraft system malfunction. If the weather was questionable; or if there was any question of go-around performance due to terrain we would have definitely discontinued the approach and reconfigured the aircraft.
B777 Captain reported a primary flaps failure and ran the appropriate checklist. They opted to deviate from the checklist and land with more flaps than the checklist dictated.