On my high altitude IFR maps (H-1 though H-6) they have VFR or VFR On Top in the cruising altitude "compass". What does VFR On Top mean, and why is it there if no VFR is allowed above 18,000 MSL?Chris

VFR On Top is a clearance that is left over from years ago. The pilot is on an IFR flight plan (clearance) but requests and is cleared to maintain a VFR altitude in VMC conditions, now assuming responsibility for his/her own separation, but required to fly the previously assigned (or modified) route. It has very little practical use anymore, especially with higher performance aircraft. In my 34 years in various forms of FAA ATC, I really can't remember seeing it requested maybe more than twice in the last 15 years. There would have to be a most unusual situation for it to benefit a pilot. Roger

Vfr on top is a clearance that allows you to remain in the IFR system, yet choose your own VFR cruising altitude.If you are using a VFR on top clearance-you must fly the appropriate VFR cruising altitude, comply with minimum visibilities, and cloud clearance requirements, follow see and avoid procedures, and adhere to all IFR flight rules applicable to the flight (i.e. MEa's, Mra's etc.). When doing my multi engine training we several times got an pop up ifr clearance for vfr on top at my class C airport to takeoff from the field in ifr conditions-climb above the local clouds-and then do multiengine maneuvers in vfr conditions above the clouds.I think the logic of the no VFR above 18,000 ft. is that most aircraft flying at and above those levels are going very fast. See and avoid is harder at those speeds-requiring ifr ensures safety.Hope that answers your question.http://mywebpages.comcast.net/geofa/pages/rxp-pilot.jpg

Thanks guys. That makes perfect sense to me.Chris

My understanding of VFR on top was the use of VFR flight above the clouds where the terrain was not visible; After a take off in IFR conditions then climbing to "VFR on top" of the clouds.

There's something that sounds similar but is very different- an IFR clearance "To VFR on top". This is requested on the ground, and is where the IFR clearance is terminated when in VFR conditions, and the flight continues as a VFR flight. The original question referred to "VFR on top", which is a clearance obtained in-flight, and has elements on both VFR and IFR to it, but the IFR clearance is still valid.Yes, it is confusing! Then add terms such as "contact approach" and such, and it gets even worse. I often think that the IFR written should feature alongside the PhD. thesis in complexity!! :)Bruce.