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 ?
Transfer CG control is another question, pls read the first sentences:
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.
TRIM TRANSFER CONTROL
Before each flight, the crew inputs the A/C Zero Fuel Center of Gravity
(ZFCG) and Zero Fuel Weight (ZFW) data into the Flight Management
Guidance and Envelope Computers (FMGECs) via the MCDU.
The two FMGECs independently transmit this data to the FCMCs.
Each FCMC uses the ZFW from the FMGECs and the tanks fuel weight
to calculate the A/C Gross Weight (GW).
This GW is output to the ECAM FUEL page, and is used, in the FCMCs, to
obtain the target CG from the memorized CG versus percentage of Mean
Aerodynamic Chord (MAC) CG table.
In the same time, the FCMCs calculate the fuel weight CG using the FQI,
the pitch, roll and acceleration data from the Air Data Inertial Reference
Units (ADIRUs) 1 and 2, and the THS position from the Flight Control
Data Concentrators (FCDCs).
Then, with the ZFWCG transmitted by the FMGECs and the fuel weight
CG, the FCMCs calculate the Gross Weight Center of Gravity (GWCG).
This GWCG is output to the ECAM FUEL page.
The FCMCs, in their transfer logic part, compare the GWCG with
the target CG to determine if a FWD transfer or an aft transfer is needed.
CG control during automatic operation:
The master FCMC has full control of the A/C CG when the A/C is above
FL255, until the A/C descends below FL245.
The FMGEC independently monitors the CG of the A/C.
If it detects that the A/C CG is too far aft, it sends a signal ''CG target FWD'' to the FCMCs.
The master FCMC moves the target CG forward 2.0% MAC.
This is latched until the end of the flight.
If the FMGEC detects that the CG is still aft of the new target CG, it
sends a signal to the FCMCs.
The FCMCs then move the target CG forward 0.5% MAC for 10 minutes.
After 10 minutes the system goes back to normal operation.
This procedure can occur twice more until the target CG is first 4.0%
then 6.0% MAC forward of the initial position.
If the error is detected again, the FCMC stops the CG control and shows
an ECAM warning to the crew.
The crew then manually sets a forward transfer.
FCOM figure Posted earlier by Takata:
LINK