Jetlagged From United Kingdom, joined Jan 2005, 2606 posts, RR: 25
Reply 1, posted (3 years 11 months 1 week 5 days 3 hours ago) and read 3200 times:
There should be no need to edit FMC weights in flight and it could be unsafe to do so. Thus it's logical that the INIT B page is inhibited once the engines are running and therefore weight is changing. Airbus uses the same philosophy on their FMCs, though if gross weight has not been initialised before engine start it's possible to enter it via the fuel prediction page. I don't know whether the Fokker 100 FMC has the same possibility on it's FUEL PRED page.
The glass isn't half empty, or half full, it's twice as big as it needs to be.