>The calculation is done by the plane’s flight computer. Not exactly true. The dispatch release has a flight & performance plan based on the load manifest. It

>The calculation is done by the plane’s flight computer. Not exactly true. The dispatch release has a flight & performance plan based on the load manifest. It's calculated out of band (here, by the software vendor) and punched into the airplane configuration for departure. If the plan is wrong, the plane flies wrong. GIGO at its finest.