Originally Posted by Escape_Slide
Be careful you guys. Do not do procedures NOT based on your FCOM. Your operator may have their AOC suspended.
FCOM states that ATHR usage, IAE engines case in point, requires a 5kt margin on top of VLS.
Now. You are on approach and on the PFD VAPP=VLS. This could because the load sheet is out- Gross Weight FAC & Gross Weight FMGC are routinely three tonne out in my experience. Or is it the alpha probe calibration? Possibly FMGC alogorithm errors quoted at +/- 2 to 3kts.
Do you add 5kts to the VLS on the PFD or accept the 5kt requirement for the use of ATHR is OK based on perf appr page data ie: FMGC computed weight?
FCOM doesn't protect you here Escape Slide. It's your decision. Your airmanship comes into play.
Personally, I ensure the 5kt buffer on PFD VLS. Frightening the thought of being 3 tonne overwight, who knows where the c of g is, flying at VLS, with this particular problem exascerbated when landing at MLW.