ATCinWI Senior Member Illinois

Yeah, it's not required that a pilot cancels IFR when reaching VFR conditions; I just do it as a hint that they *can* cancel. My (limited) experience has been that if you don't tell the pilot to report reaching VFR conditions on top AND report canceling IFR, then they won't cancel, even if they want to; they think that reporting that they're in VFR conditions IS their cancellation (it's not a common procedure for pilots, either . . . I'd say less know about VFR on top than, say, SVFR, which, I'm finding, is not as well-known as I thought).

He's on an IFR flight plan, but he's providing the separation . . . as long as their is some sort of separation, you're legal, right? We use visual separation all the time, right? Pilots in VFR conditions are still supposed to see-and-avoid, even on an IFR flight plan (although if at a hard altitude and route, ATC has the responsibility in controlled airspace). If they're flying VFR-on-top, it lets them climb and descend and maneuver as they need to to stay VFR and avoid other traffic, but retain their IFR clearance.

Kind of hand-in-hand with VFR on top is the VFR climb of an IFR aircraft. I have never seen this before, but I watched a CBI a while ago on it . . . "Climb VFR between 5000 and 14000" or something like that . . . it's pretty much the same thing.