fredgrav <<but if you are being vectored, and flying with AP OFF, FD should also be selected OFF, and FPV alone might help you keeping the path>>
No! The time you have to worry about taking the FD off (with regards to this) is if you are not following them. You can perfectly happily fly the aircraft around AP off FD/Athr on in thrust or speed mode during vectoring, or most other stages of flight.
<<I was referring to an AP OFF + FD + ATHR ON condition: here the A/THR is still in THRUST mode>> No, it depends on the vertical mode selected, you could easily have a VS selected and a heading to intercept the ILS, hand flying it, FD + AThr on, selected or managed speed, the aircraft will be in Speed, V/S mode HDG and LOC blue AP off Athr on 1FD2
The time it is very important to bring FD's off to get speed mode is really either a visual approach where the flight directors will offer no guidance obviously, or continuing visually after a non-precision approach or a TCAS RA when you will ignore the flight directors hence you need to turn them off to get speed mode.
I take it you have never flown the aircraft?
Last edited by tom775257; 7th April 2010 at 12:42.