Island-Flyer
The entire flight may have lasted 9 hours, but the tricky problem just came up on final approach to Warsaw. Until then it had just been a case of, lost centre hydraulics, gear will be extended by alternate gear sytem, no need to wake up Boeing for such a straight forward situation.
Joker 72
Code:
No electrical power, no gear extension, regardless of status of the center hydraulic system.
I hope you do realize that with centre hydraulics available, there is no need for alternate extension, and gear can be extended normally, without any electrics (with normal extension, uplocks are released by hydraulic actuators).