Manley,
Not to pick nits, but the leading edge flaps (e.g. inboard krugers) are actually hydraulically operated. They droop open on the ground until ADP's (air driven hydo pumps) are turned on or engine-driven hydro pumps start up. The fiberglass leading edge slats, however, are air-driven, activated by the PDU's (Pnematic Drive units.) But you don't need those until the "Slats retract call." It won't crash loosing air because the PDU has an internal locking mechanism. It is well known that inop bleeds can be defered and wired shut. MEL restrictions then apply.
Agreed, some bleed is needed to pressurize the air "head" on the hydro reservoirs, ADP gear service assist etc. So I guess the 4 bleeds off was the 146 or something.... my apologies.
I remember that you can t/o with the apu running (you actually get 600 lbs extra thrust out of it! But can't count that.) Refresh my memory here.... can the APU supply any elect or pnem demands during t/o (per ops procdrs)? Maybe it was just for back up....
I'm doing pretty good on this oral, huh?
Hand me a bigger shovel so I can dig deeper....
