does the Boeing B-747 have a fly by wire flight control system or hydraulic assisted???
It's not fly by wire. You think they would stoop so low as to use fly by wire? It's a MANS airplane.
The Boeing 747 has a mechanically controlled, hydraulic flight control system. It is not hydraulically assisted unlike the 727 and 737. Without hydraulics the flight controls will not move (except the stabilizer trim). The only Boeing aircraft that is fly-by-wire is the 777 but the 787 is also supposed to be fly-by-wire. Most fly-by-wire systems are hydraulically driven but newer systems are using electric actuators.
Boeing has a lesson learned book of knowledge they design aircraft to. The B-747 have several system install for flight controls. As an example the primary control surfaces Stabilizer and rudder are controlled by dual multifunction computer and flap control includes three computer systems. The horizontal stabilizer trim: fly-by-wire high lift, and dual yaw dampers, which include modal suppression, provide control simplifications. Permanent indexes define the rigging positions of control surfaces and rigging pin positions are readily available. Its hard to believe the rudder trim is a cable control system thru the forward quadrant to a stabilizer trim and rudder ratio module back to the aft quadrant which controls the power control actuators. So it is not a full fly-by-wire system but a little of both fly-by-wire and hydraulic assist.
