Small Aircraft; Low Wing; 1 Eng; Retractable Gear
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 0.4
Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Separated Traffic
Company Policy; Procedure; Human Factors
Aircraft X was on a practice ILS approach. On the missed approach; I issued runway heading for a jet that would be departing behind and turning northeast. Aircraft Y was told about Aircraft X ahead of him on the departure end of the runway and that he would be turning inside that aircraft; then cleared him for takeoff heading 060. When Aircraft Y was on a roughly half mile departure he advised me; and I could also SEE using TOWER Applied Visual Separation; that he was in the right turn and absolutely no factor for Aircraft X. When Aircraft Y was well established in the turn; as was VISUALLY assured out the window; I shipped him to Departure Control. Once I visually observed Aircraft Y well established in the right turn to 060; I told Aircraft X to turn right heading 040; which is the standard missed approach as per the Letter of Agreement with TRACON and 20 degrees outside of Aircraft Y who made his 060 turn IMMEDIATELY after departure. Both aircraft knew about each other's intent. Runway Separation was applied prior to using visual separation; and then Departure Degree Divergence was applied after visual separation.I firmly believe that there is no issue with this operation and this report is being filed reference a Mandatory Occurrence Report. Things look VERY different looking out a window to separate aircraft than they do on a RADAR scope having both Tower and RADAR experience. This is simply an alarm based on RADAR environment rules when VFR Tower operations were being applied in a completely safe manner. I don't have a recommendation. Just too please be aware that VFR Towers are using Tower Applied Visual Separation differently than Visual is used in a RADAR environment.
A Tower Controller reported following all the guidelines for Tower Visual Separation and Degrees Divergence rules that may have been considered as an operational error.