Greeting everyone,
I'm currently doing line training on the A320 and I'm trying to find out how the FMGS makes fuel and time predictions when we insert wind value in the Init page on the ground. As I did not find anything on the FCOM, I'm requesting your help:
Assuming airport elevation is sea level and cruising flight level is FL350:
In the climb wind phase if I only insert: "230/25/2000": Will the FMGS assume this value from 2000 feet until FL 350 and zero wind condition from ground to 2000 feet?
Second question: still in climb phase, now if at Waypoint Alpha: I Insert: 110/10/2000 and second wind update at Waypoint Kilo: 130/20/4000... Will the FMGS interpolate the 2 different winds in between waypoint "Alpha" and "Kilo" and assume a wind of"120/15/3000?? Or will it assume the exact wind value inserted at A until reaching Kilo then assume wind inserted at Kilo until reading top of climb? Or none of this?
I assume it's the same computation for the wind during cruise phase and descent phase.
Now , I read somewhere on Pprune that during actual flight the FMGS useS for fuel prediction the actual wind (display in the ND) for short distance and still use the inserted wind for Waypoints further away and the distance depending if it is the Thalès or Honeywell FMGS.. Could someone provide the exact value?
Last question: Assuming you fly from EDDL to LFPG and you insert LFPO as alternate. But you do not build up the destination alternate route... Will the fuel prediction( extra time) consider a flight from EDDL TO LFPG and a straight line to LFPO or disregard the alternate and the extra time is only after assuming a go around at LFPG + 30 min holding?
That's it
Thank you for your time.