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No ZFW on MCDU

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Old 2nd Nov 2013, 03:52
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No ZFW on MCDU

I can no longer find the consequences of neglecting insertion of performance data on the MCDU for departure as it used to be on FCOM 4.
if i can get some help with that. thank you.
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Old 2nd Nov 2013, 06:33
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Once the Engines are running you can't get INIT B.
Therefore FUEL PRED page you can enter GW/GWCG.
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Old 2nd Nov 2013, 06:38
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MD83FO

FCTM PAGE SI-040 P 1/4 A to B
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Old 2nd Nov 2013, 07:01
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I wasnt specific, my mistake.
It has to do with how will the FMGC react in flight if there is nothing on the MCDU.
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Old 2nd Nov 2013, 07:42
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PRO-NOR-SRP-01-10 P 25/32


TAKEOFF WITH NO WEIGHT/CG DATA
If the crew does not enter ZFW/ZFWCG data prior takeoff, or if the FMGC looses these values due
to a power interruption, the following will occur:
‐ At takeoff, the Speed Reference System (SRS) mode is available (provided a V2 has been
inserted)
‐ When the aircraft leaves the SRS mode, the target speed becomes the current speed and
reverts to selected.
Note: If the AP/FD has reverted to ALT or V/S (FPA) mode, the associated A/THR mode is
SPEED. In this case, the system will probably reduce thrust, because the speed will be
equal to, or greater than, the target speed.
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Old 2nd Nov 2013, 10:50
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thank you guys
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Old 17th Nov 2013, 19:37
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Hello MD83FO


Here´s wht you find in the AI FCTM :





ERRONEOUS ZFWCG ENTERED


The CG computed by the FCMC is erroneous. This induces the following

consequences:


· Incorrect CG is displayed on ECAM SD and on MCDU FUEL PRED page

· CG regulation is affected but “EXCESS AFT CG” warning remains




reliable.


· Minor impact on FM predictions.

· Additionally, VLS and Vapp speeds on MCDU PERF APPR page are



impacted (A340-500/600 only).


· At take-off, the pitch trim setting might be erroneous. This is minor since



take-off has been certified in full forward CG with full aft trim and vice

versa.


· In flight, the PRIM operate with CG=30% which has minor consequence



on the aircraft handling


· AP/FD control laws are slightly affected

· VLS displayed on PFD is impacted (A340-500/600 only)



Vaprot, Vamax, Vsw are not affected since based on aerodynamic data.





Regards




ERRONEOUS ZFW ENTERED



GW and, to a lesser degree, CG computed by FCMC are erroneous. This induces

the following consequences:


· Incorrect GW and CG displayed on ECAM and on MCDU FUEL PRED



page


· CG regulation is slightly affected since the aft target CG depends on the



weight but “EXCESS AFT CG” warning remains reliable.


· The SRS mode guidance may be affected (If VLS > V2 inserted on



MCDU PERF TO page).


· FM predictions and speeds are affected

· The FG and PRIM control laws are slightly affected

· The characteristic speeds displayed on PFD are affected.


Vaprot, Vamax, Vsw are not affected since based on aerodynamic data.
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