A33Zab
In Flight:
The FMGC uses the weight and center of gravity from the FCMC (Fuel Computer) when available.
The GW and CG computed by the FE part are used:
– as back-up in case of dual FCMC failure.
– to trigger the aft CG caution and warning signals (independently of the FCMC).
FE Weight computation (back up)
– When the aircraft is below 14625 feet and 255 knots :
GW = f(α, CAS, N1/EPR actual, CG from FE part, altitude)
– When the aircraft is above 14625 feet or 255 knots :
GW = TOGW − WFU
TOGW: takeoff gross weight
WFU: weight fuel used acquired from FADECs.
FE Center of gravity computation (back up/aft cg computation)
The CG is computed from the position of the horizontal stabilizer and is
function of the N1/EPR, Vc, ALT, MACH and GW from FE part.
thank you for detailed explanation A33Z
so in case of wrong CAS, MACH or ALT datas, what may be the result or the following aktion for the the FE Weight or Ceneter of gravity computation ??? in which direction will he put the wrong datas in his calculation? will he start pumping more fuel back or forward if the bird fly in level 350 with a (mayby) wrongly indicated CAS <255 ?