Cessna 210 Centurion / Turbo Centurion 210C; 210D
Air Traffic Control Fully Certified
Situational Awareness
Conflict NMAC
General None Reported / Taken
Airspace Structure; Human Factors; Procedure
Aircraft X; C210 IFR on Visual Approach to our Runway 23 (Point out/hand off taken approx 15 miles out) made first contact with MMU Tower approximately 5 1/2 to 6 miles. At the time I had other operations in progress at the runway. When I checked progress of Aircraft on the RACD; it was rapidly approaching from the West; range approximately one mile indicating same altitude. In the initial contact; pilot stated that he had a (Cessna) in front of or between him and the airport. I had no time to issue traffic as the aircraft were already together. I issued landing clearance to aircraft and asked if Approach had issued the traffic. The pilot replied in the negative. ZZZ1 Tower called advising that one of their pilots said something about a close call. I could not make out clearly the full gist of what ZZZ1 Tower was trying to tell me. I called the FBO and requested they have the pilot of Aircraft X call me in the Tower. When the pilot called; we discussed whether the incident warranted the filing of a NMAC report and the decision was made to file. The pilot also indicated that he thought training was in progress on Approach Control. In speaking with ZZZ1 Tower; it was determined that the other aircraft involved was Aircraft Y; a C172; and that the pilot seemed 'shaken'. Shortly after; my Tower Manager told me that since both aircraft were operating visually that there was no NMAC. That appears to be a personal interpretation. Although the AIM mentions a definitive 500-foot proximity in this definition; it goes on to allow the pilot; or flight crew member; to make a determination as to if a collision hazard existed regardless of how close the aircraft came to one another. More pilot education is needed on the part of some operators. A large amount of their traffic arrives from the West; crossing our Runway 23 approach area. My FLM has previously issued a letter the the local Aviation Community describing the hazard associated with this airspace.
A Tower Controller described a conflict event between IFR arrival traffic and VFR traffic transiting the area. The incident prompted a discussion on the interpretation of a NMAC and the rules governing same.