Narrative:

I was working local control and departed aircraft X VFR right downwind to the east. Initially; I issued traffic to the pilot that was approximately 3 miles northeast of his position. As the traffic converged; I gave aircraft X a suggested right turn of 20 degrees to avoid traffic. I reached out to the traffic opposite direction and they happened to be inbound to the field with traffic in sight. I gave aircraft X an update of the traffic and they reported traffic in sight as well. Aircraft X was instructed to resume own navigation and remain outside B with a frequency change. No traffic was observed east of aircraft X within the scope of my racd settings. Minutes later; aircraft X reported a near miss with an aircraft that was westbound. This occurred at least 10 miles east of myf. The traffic was outside of the scope of my racd settings and I was unaware and unable to advise aircraft X of that traffic. By the time the aircraft Y checked in; traffic was not a factor. Aircraft Y never had aircraft X in sight. Pilot of aircraft X was told to give the tower a call on the land line. I don't have any particular recommendations for the event. Our priority is to focus on the runways and aircraft in our airspace. We provide additional services; however; there is a limit to how far we zoom out on our radar screens. Being too focused on what's beyond the scope of our radar maps will take our eyes off of our D airspace and our runways and will result in a greater safety issue.

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Original NASA ASRS Text

Title: MYF Tower Local Control reports of a near mid air that was reported by a pilot after it left the MYF Class D.

Narrative: I was working Local Control and departed Aircraft X VFR right downwind to the east. Initially; I issued traffic to the pilot that was approximately 3 miles northeast of his position. As the traffic converged; I gave Aircraft X a suggested right turn of 20 degrees to avoid traffic. I reached out to the traffic opposite direction and they happened to be inbound to the field with traffic in sight. I gave Aircraft X an update of the traffic and they reported traffic in sight as well. Aircraft X was instructed to resume own navigation and remain outside B with a frequency change. No traffic was observed east of Aircraft X within the scope of my RACD settings. Minutes later; Aircraft X reported a near miss with an aircraft that was westbound. This occurred at least 10 miles east of MYF. The traffic was outside of the scope of my RACD settings and I was unaware and unable to advise Aircraft X of that traffic. By the time the Aircraft Y checked in; traffic was not a factor. Aircraft Y never had Aircraft X in sight. Pilot of Aircraft X was told to give the Tower a call on the land line. I don't have any particular recommendations for the event. Our priority is to focus on the runways and aircraft in our airspace. We provide additional services; however; there is a limit to how far we zoom out on our radar screens. Being too focused on what's beyond the scope of our radar maps will take our eyes off of our D airspace and our runways and will result in a greater safety issue.

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.