The flaps/slats on Delta's 737-200s are powered by A system hydraulics while the flaps/slats on our 737-300s and 800s are powered by B the system.
Three questions. Do all 1st gen 737s have A system powered flaps? Do all subsequent generations have B system powered flaps? Most importantly why did Boeing switch the system that powered the flaps from A to B?
p.s. No this is not another A vs B thread.......or is it?