Robert Chambers wrote:

Or unless you cancel in the air which is sometimes easier to do at a
field with no RCO or a tower that is closed.

You can also cancel in the air to help people out, I've been on an IFR
plan (but by the time I was approaching the field was VFR conditions)
and I heard a Jet at the hold short "ready for release" the tower said
"I have one IFR arrival inbound, expect a 3 minute delay" once that was
acknowledged I said "N1234 is cancelling IFR at this time" got the
cancellation and they released the jet to go before I got there. The
jet jockey (which surprised me) threw me a thank you before he got
switched over to approach.

Anything to make the system work that makes sense is ok in my book.



Three lousy minutes? The tower should have used visual separation and
let the jet go.