Narrative:

Aircraft X called wanting a frequency to file a VFR otp flight plan. I identified the aircraft and asked if he could maintain his own terrain and obstruction avoidance through 025. He stated that he could; so I issued the clearance. He reported on top at 014 which was below a layer that had been giving VFR pilots trouble. I was concerned about the aircraft being on top so far below the mia that I restated the clearance and the aircraft started to climb. I was busy so I put in a VFR on top flight plan and then did other tasks. Soon after; aircraft X declared an emergency and stated that he was turning to land at ZZZ. I obtained the emergency info and issued distance and direction to the airport. He got the airport in sight and I gave him a phone number to call so we could know he arrived safely. Later; I realized that I treated him like a VFR aircraft. I never issued him an altitude to maintain nor did I clear him for a visual approach. These are things I would do with any other aircraft. I assume I made this mistake because I never updated the data block to show VFR/otp and the VFR in the data block just led me down the wrong path. The aircraft landed safely.I could tell that I was getting behind so I should have asked for help. Also; I would update the data block immediately or if I had help I would use the template.

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Original NASA ASRS Text

Title: Controller describes a situation where the aircraft is VFR on top and declares an emergency. The aircraft is never given an altitude to maintain or a clearance for a visual approach to the airport.

Narrative: Aircraft X called wanting a frequency to file a VFR OTP flight plan. I identified the aircraft and asked if he could maintain his own terrain and obstruction avoidance through 025. He stated that he could; so I issued the clearance. He reported on top at 014 which was below a layer that had been giving VFR pilots trouble. I was concerned about the aircraft being on top so far below the MIA that I restated the clearance and the aircraft started to climb. I was busy so I put in a VFR on top flight plan and then did other tasks. Soon after; Aircraft X declared an emergency and stated that he was turning to land at ZZZ. I obtained the emergency info and issued distance and direction to the airport. He got the airport in sight and I gave him a phone number to call so we could know he arrived safely. Later; I realized that I treated him like a VFR aircraft. I never issued him an altitude to maintain nor did I clear him for a visual approach. These are things I would do with any other aircraft. I assume I made this mistake because I never updated the data block to show VFR/OTP and the VFR in the data block just led me down the wrong path. The aircraft landed safely.I could tell that I was getting behind so I should have asked for help. Also; I would update the data block immediately or if I had help I would use the template.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.