PPRuNe Forums - 737) Why do manually enter weight when it was Both FMC fail?

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sourirelns

8th May 2012 12:18

737) Why do manually enter weight when it was Both FMC fail?

Hello everyone~
Why do manually enter current gross weight when it was Both FMC fail?
I know why put in the Vref and goround N1.
But I can't understand why put in the current gross weight by SPD REF selector...
It's not the FMC works anyway.......
Is that I enter the weight to change anything?
Is it only reference?

Sorry, English is not good...
:p

Denti

8th May 2012 13:29

To display the correct UP speed the system needs to know its current weight, same for the intermediate flap positions (for example, take off flaps 5, the system displays the "1" speed as well). Same for approach settings, the UP speed is displayed based on weight.

sourirelns

9th May 2012 01:22

Ah ha!!!
Thanks!
Thanks a lot!!:ok:

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