Originally Posted by
Sam Rutherford
The only information I have found on this is here:
https://www.foreflight.com/support/f...t-plan-filing/
"A VFR flight plan can only be activated with your FSS in the time period of one hour before your filed departure time to two hours after. An IFR flight plan can be activated with ATC in the time period of two hours before your filed departure time to two hours after."
That appears to me to be a discussion of US procedures, if so, of limited relevance to determining local nuance in Belgium.