B747-400
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 120; Flight Crew Total 17400; Flight Crew Type 950
Fatigue; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation - Altitude Overshoot; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Flight Deck / Cabin / Aircraft Event Other / Unknown; Inflight Event / Encounter Unstabilized Approach
General Maintenance Action
Aircraft; Human Factors
We had a HYD LOW QTY and completed the checklist by turning off the ENG and AUX PUMPS on Number 4 shortly after reaching cruise. Prior to TOD we revisited the checklist and determined that we should turn the pumps back on prior to gear extension. In the checklist it says to turn the pumps on before using FLAPS AND GEAR. The PF turned off the autopilot and hand flew the approach. When calling for flaps 1; we got the FLAPS PRIMARY caution. So the flaps were slow to extend. Turning on the pumps late did not cure the problem. Read the checklist to confirm the situation and turned base for the airport. The First Officer was confused with the display of the secondary flaps and was trying to control speed and altitude while monitoring a new display.Communication was lacking due to 14 hour duty day and jet lag. I turned on the autopilot as PF was approaching cleared altitude. The bunkies were very involved with advocating corrective actions for the descent through cleared altitude by 400 FT. The Controller confirmed we had the airport and gave us the visual. Typical [approach] that put us a little high on final with our own problem of self inflicted slow flaps. The rest of the approach and landing were uneventful. I debriefed the crew regarding use of autopilot to reduce workload; and how we interpreted the wording of the checklist was wrong and a 14 hour duty day the checklists should be pretty straight forward. On this particular checklist; I would advocate for the words to turn on the pumps before using flaps or gear. With a warning of what will happen if you start using flaps without Number 4 pressurized.
[Narrative 2 had no additional information]
A B747-400 flight crew deviated from their heading and altitude clearance while dealing with a hydraulic problem.