Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 25
Confusion; Distraction; Situational Awareness; Training / Qualification
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance
Human Factors; Procedure
I was training at the BEARZ D. Aircraft X was on frequency (don't remember where he departed) at 14;000 to BMI. He stated '14;000 is right in the tops; requesting a climb to VFR-ON-TOP.' The radar trainee was unfamiliar with the procedures and her instructor directed her to use the EDST [En-route Decision Support Tool]. VFR-ON-TOP procedures are indexed on the ZAU reference page; my trainee located the paragraph in the 7110.65 (kudos to whomever compiled the reference page. In this instance; it worked flawlessly and was a great help) and the four of us were able to discuss the VFR-ON-TOP clearance. The trainee fumbled through the phraseology the first time; then I corrected her and showed her the phraseology example listed in the 7110. We had no other traffic and she issued the appropriate clearance. The pilot reported reaching VFR conditions on top; and after corrections from her instructor and me; she issued the appropriate response. 'Roger; maintain VFR.' Aircraft X leveled at 14;500.We initiated a handoff to EON (sector 44) and the R-side transferred communications thusly 'For further VFR flight following; contact Chicago Center 120.12.' My trainee and I discussed VFR on TOP and its applications. I explained that it's an IFR clearance and the appropriate computer entries. Later the EON controller called and questioned Aircraft X's clearance. Based on her explanation; I believe Aircraft X did not fully understand his clearance that after reporting reaching VFR ON TOP and the R-side's clearance 'Maintain VFR;' he was VFR. I don't believe it's clear that while VFR-ON-TOP is an IFR clearance; once the pilot reports on top and is instructed to maintain VFR; whose responsibilities are what? I don't think I've seen phraseology 'Cancellation of IFR received.' I thought it was odd an IFR aircraft requested an OTP clearance; climbed to a VFR altitude; was told to maintain VFR.
ZAU Controller reported issuing a VFR on top clearance and confusion ensued as to what the pilot and Controller responsibilities were.