Helicopter
Air Traffic Control Fully Certified
Situational Awareness
ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Airspace Structure; Procedure; Human Factors
A helicopter was outside Class D airspace on a northbound transition west of Krome Ave.  A C172 was in the VFR traffic pattern conducting touch and goes.  Just north of the 5 mile final of RWY 9L; the helicopter pilot informed me that it had a close call with the C172.  I asked how close it was; he informed me it was about 100 feet separation.  Recommendation for this event not happening again would be to give traffic advisories to aircraft in close proximity.  I was busy handling the five aircraft in the traffic pattern and forgot to call traffic to the helicopter.  I have to maintain better awareness.
Tower Controller is advised of a NMAC by a helicopter pilot transitioning northbound through the Class D; with a C172 in the VFR traffic pattern.