Hello. I've searching for this everywhere on the internet and found out the Internet doesn't satisfy me at all. I only can gathered answers around other planes like B737 hydraulics and such, but not the B747. I've came up with the question on Quora yet the answers dissapoint me further. This is so frustrating. On Boeing 747-400 hydraulics system, if one of the four system fails in-flight, what would happen to the system? How does other system back-ups the failing system in advance? Would you show me the detailed explaination along with its detailed schematic diagram? True, there are schematics diagram for B747 hydraulics but that's simplified. I need to know the detailed circuitary ones. This is for my assignment and my lecturer requires me to have this kind of explaination. Thank you.