Jet/Long Ranger/206
Air Traffic Control Fully Certified
Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert
Human Factors
A Bell 206 was inbound from southwest and requesting to land on the north ramp. A Cessna 172 was in the VFR traffic pattern; and I also had two IFR inbounds landing XXR. As the B206 approached the airport; I realized he'd likely become a conflict once the C172 was back on the upwind in the pattern; so I instructed the B206 to turn northbound and advised him there was traffic in the pattern (C172). I observed B206's RADAR target turning northbound; and once I believed he had flown a sufficient distance to get north of XXL departure end; advised he could 'resume on course' to land as he requested on the ramp. I scanned the position of the C172 (on the runway) and then began looking for the B206 to the west and suddenly spotted the B206 near the departure end of XXL with the C172 on the upwind.  I immediately issued traffic to the B206 and he advised he was looking and determining it was a traffic alert situation; immediately issued the helicopter traffic to the C172. I observed the C172 appeared to be maneuvering to avoid the helicopter as the helicopter reported him in sight. It frustrates me that I allowed my desire to expedite the helicopter's approach back to the ramp to result in a traffic conflict that was avoidable with stronger restrictions to the B206. As the event unfolded; I felt I was providing sufficient positive control up until the point where I allowed the helicopter to turn back on course; but in hindsight; more restrictions were needed to ensure the helicopter stayed a sufficient distance away to avoid the fixed wing operation in the pattern. I may have assumed that the pilot knew to stay clear of the active runways (since there was traffic in the pattern) and I was attempting to expedite the helicopter's operation back to the ramp; since he was involved with SAR/relief operations. However; this is a harsh reminder that providing priority to special operations (MEDEVAC; relief flights; law enforcement; etc.) is important but never to the extent that it compromises safety.
Tower Controller described a conflict event when he provided expedited service to a SAR helicopter arrival that eventually conflicted with VFR pattern traffic.