Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
ATC Issue All Types; Conflict Airborne Conflict
Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action
Procedure
On takeoff from COS we were delayed due to several training aircraft in the pattern. Shortly after takeoff from 35R tower said there was an aircraft in front of us and switched us to departure. Departure then informs us that there is traffic in front of us and turning to a 360 degree heading. We did not have the aircraft in sight. I mentioned to the First Officer; who was flying; that the aircraft was not in sight though showing at our altitude as we climbed. The TCAS showed 100 ft below us and slightly left when we received the RA to climb. The FO disconnected the autopilot to comply with the RA.ATC launched us into single engine slower traffic which we overtook quickly on takeoff. ATC made no effort to separate converging aircraft. Keep smaller single engine aircraft out of our departure path.
Air carrier Captain reported a TCAS RA departing COS caused by a GA aircraft that had departed just before. COS Tower was controlling both aircraft initially.