Large Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (mon) 1
Training / Qualification; Situational Awareness; Confusion; Distraction
ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action
Procedure; Human Factors
I had taken a handoff from Wooly Sector with VFR Aircraft Y when he was 9-10 miles to the NW of BWI. When he checked in I told him to proceed direct to [our hospital] and that there were going to be departures off of runway 28. I had quite a few departures that were lined up at the end of the runway. I had departed a few B737 and they had been climbing well and over where Aircraft Y would be crossing the extended center line of runway 28. After clearing Aircraft X for takeoff I called traffic to Aircraft Y when Aircraft X was rolling midfield to be safe. Aircraft Y said that they were looking for the traffic. I saw that Aircraft X was not climbing like the previous departures. After Aircraft X was airborne I then told him the traffic and he also said that he was looking. I saw the traffic outside and saw that they were getting closer and they both did not have [each other] in sight. I continued to call the traffic to both aircraft giving them updates on their current location. After doing another traffic call Aircraft Y said that they had seem them. At that point Aircraft Y was still at 2500-2600 feet and Aircraft X was around 2100. I observed Aircraft X turning north to advert away from the traffic. Aircraft X then said that they were turning back on course and that they had a Resolution Advisory (RA); and he was still climbing. At that point they were past each other and were no longer a factor. I told Aircraft X to contact Potomac. Aircraft Y continued south bound towards his destination and was handed off back to PCT.Be more aware of aircraft performance.
We were cleared the TERPZ4 departure climb via SID to 4;000 off of RWY 28. Shortly after takeoff ATC made a very timely and accurate traffic call of a helicopter at our 1 [o'clock]; 2500 feet; heading south.  We acquired the helicopter on TCAS and shortly after visually.  We were on a collision course with zero LOS (Loss of Separation) and climbing into the helicopter.  Recognizing it would be difficult to level below or out climb; I turned right/north to pass behind the helicopter.  After the maneuver was in progress we received an RA after we had generated lateral clearance.  Estimate we passed behind the helicopter between 500 and 1000 feet.
BWI Controller and airline pilot report of a NMAC. Controller thought climb rate would be better for the air carrier based on previous departures. Once the pilot acquired the aircraft visually; a turned was made to avoid it.