B747 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural MEL / CDL
Flight Crew Returned To Departure Airport; Flight Crew FLC complied w / Automation / Advisory
Aircraft; MEL
Captain flying. Dispatched with Number 1 engine driven hydraulic pump inop. Flight had reached 32;000 ft cruise and approximately XA:40 we got master caution; autopilot disengaged and EICAS message HYD Press Eng 1. After reviewing HYD synoptics display and confirming loss of Number 1 HYD system. Appropriate checklist was run without regaining the Number 1 HYD system. The SAT Com was used to contact dispatch; [maintenance] and [company]. Captain made decision to return. Fuel was dumped. In preparation for landing the FO (First Officer); per checklist; selected alternate gear extension switch and it came apart in his hand. He was able to activate the switch. In the alternate mode; we noted flaps not extending equally. We got EICAS flaps drive message. Checklist run. Now limited to flaps 25 landing with high VREF speed. We requested longest runway. The aircraft had to be towed to ramp. The tug broke down halfway to [parking] on taxiway Romeo. A second tug was sent to rescue broken tug and a third sent for aircraft. From stopping on runway to block in on ramp took 1:27 minutes. The aircraft should have had HYD system fixed in [destination] where they had pulled it back into service. It is concerning that [the company] seems to be 'skimping' on maintenance and ultimately safety. Also concerning that while communicating with dispatch and [maintenance]; they were not aware that the engine driven hydraulic pump was MELed (inop).
[Report narrative contained no additional information.]
B747 flight crew reported loss of Number 1 hydraulic system in cruise after being dispatched with Number 1 engine driven hydraulic pump on MEL. Flight crew returned to departure airport with limited flaps.