"LDG DIST PROC... APPLY" - a320 question

[737Jock]

The corrections you apply take account of the flap setting to be used, even if the only option is to land conf 3.
However to clarify; some failures give you the choice of landing in flap full or conf 3, for example AC BUS 1 failure:

Conf 3: delta vref = 6 and land dist factor = 1,3 (dry no rev)
FULL: delta vref = - and land dist factor = 1,2 (dry no rev)

As you can see for the same failure the corrections to be applied are different based on the landing configuration. It is clear however that Conf 3 will give a higher Vapp and greater landing distance compared to FULL.
So the correction factors take into account the landing config and that is why you always use vref FULL and landing distance FULL as the basis.

Also the comments regarding more lift for flap full vs conf 3 are wrong. Very simply stated the lift is equal to the weight of the aircraft.
Flaps and slats generate the ability to fly at a lower speed while generating the same amount of lift, lowering the noseattitude of the aircraft (for visibility), reducing VS and producing drag. The change from Conf 3 to FULL is more about drag then lift or VS. Just look at the minor change in VLS, compared to going from clean to Conf 1 (slats only).