B747 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 150; Flight Crew Total 21000; Flight Crew Type 4000
Confusion; Distraction
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter CFTT / CFIT
General None Reported / Taken
Weather; Procedure; Human Factors
Weather during our approach and landing was night; moderate rain; moderate crosswind; and visibility about 2 miles. Disconnected autopilot at about 500 feet; and was lined up well on the runway centerline. Possibly due to fatigue; allowed profile to be less than desired. Was making correction at about the same time as the activation of the GPWS warning; 'Too Low.' I landed the aircraft at after a normal flare. Threshold minimum crossing height is 42 feet for the 747. We debriefed the approach after we landed; and also after block in. It is estimated that we descended through 50 feet just prior to the threshold; and estimate that the actual threshold crossing was about 40 feet; or 2 feet less than minimum. This was a learning experience; and I feel that we should report these occurrences. I will know to guard against this type of 'low on the glidepath' approach and landing in the future.
A fatigued B747 Captain reported crossing the runway threshold low during a night approach in moderated rain and winds.