Are flight plans in the usa optional or mandatory? Back in the 70's they were optional, I don't now if that changed after 911.?

Best Answer:

vic: ifr: mandatory. as always.

vfr: optional. as always.

in canada all flights over 25 nautical miles must be on a flight plan or a flight itinerary.

a flight plan is a document of safety, not of enforcement. if you're overdue at your destination, somebody will notice and people will start looking for you.

Other answer:

In most areas rules did not change and flight plans are not required.

A special zone was set up around Washington DC where you are required to be on a flight plan with a preassigned transponder code before entering.

Flight plans are still optional for VFR (Visual Flight Rules) flight. They have ALWAYS been required for flight under instrument rules.
Zaphod Beeblebrox:
Yes, they are still optional for VFR aircraft. The rules have barely changed in that regard except for border-crossing flights. .
Still not always required. Having to file a plan wouldn't stop anybody from ding bad things and the FAA knows it.