737) Why do manually enter weight when it was Both FMC fail?
Thread Starter
Joined: May 2012
Posts: 2
Likes: 0
From: tokyo
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...
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...
Joined: Mar 2001
Posts: 4,562
Likes: 33
From: I wouldn't know.
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.
