mcdhu, what would be your suggestion then? In fact, I wonder what is the behaviour of the FMGS. I would suppose the MCDU coding would display -3,0 deg, however when flown in FINAL APP then the observed fpa would show -3,5 or so as the altimeter error is bled off towards MAPt. Upon reaching MDA 530 ft the altimeter still significantly overreads so you are 100' (?) higher with 4 whites on PAPI. The brick, should probably provide corrective angular trajectory towards MAPt (last coded waypoint), where profile is at 160 ft AFE (my calculation, normally shown on LEGS page) and you would overfly with some - 40' (?) ft error compared to target geometrical profile.
If so, my guess is that many would say 'twas ze Airbouse doing strange again'; incidentally, the problem has nothing to do with FBW, sidestick or fixed TLs etc. etc. - as had never been the case.
If flown selected, one could make the correction and leave FAF on 1600 indicated ALT and then select FPA -3 deg.
No, my training and fear of life prohibits me from flying below charted alt. Or, knowing that on 1900 indicated you are in fact at 2200 start FPA -3 deg 1 NM before the FAF
No, my training and fear of life prohibits leaving platform 2 km before step-down fix.
My solution would be to leave FAF from 1900 [2200] but select -3,3. When visual to PAPI duck under to align and keep 3 deg profile until touchdown. Still, I admit to be undertrained.
It would be nice to learn what is the preferred technique of contributing desert specialists. Anyway, what would be the altimeter error for ISA+30 and height difference 1900' ? The deviation tablest I have are for cold weather only.
Yours,
FD (the un-real)