It means that flight plans (which include departure time) will stay in the system longer after the departure times are missed, so that IFR flight plans will not need to be re-filed. In other words, flight plans have a longer TTL.
replyThis will ease the pain of getting things moving again, assuming they fix it by the time the 4hr window passes.
Normally, a flight plan must be filed with the FAA no later than 60 minutes before it's needed. That's been extended to 240 minutes.
replySo the flight planning system is having problems.
You can definitely file a flight plan later than that. 30 minutes before departure is the recommended filing time (per AIM 5-1-6), but you can even file for an immediate departure. It's just that at less then 30 minutes additional delay is possible, depending on backend handling and human processing. But in most cases the strip will print within a minute or two of submitting the flight plan.
replyBut also, this is about when the flight plans expire out of the system if they're not activated for departure - so it's saying unused flight plans won't be deleted for 4 hours, so pilots won't have to refile for departure.