EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors
Clearance was UGAAA6 AHN transition. Push clearance was tail north; indicating a 9L departure. The FMS was programmed for 8R and was not changed. The taxi check was completed and the brief was UGAAA6; 10;000; RONII was called as the first fix; I did not catch this. We were issued to line up and wait; followed by a takeoff clearance; RNAV to LIDAS. We took off with the wrong runway programmed in the FMS and when the navigation was selected at 400 feet we were tracking the wrong course. We received an RA; complied with it; and were then issued a heading to fly to get us back on our appropriate course. We continued without having further incidences.When we were issued the push clearance indicating a 9L departure; I should have reverified the FMS. It was a busy taxi; yet in retrospect I should have set the brake and visually confirmed the FMS and the first fix. Upon accepting the line up and wait clearance I should have verified the runway on the flight plan page. The extra seconds to do these actions would have prevented this loss of separation.
This was a simple mistake that was missed by the distraction of busy ground operations; a fast taxi; and concerning weather in the area. The Captain was busy with taxiing; following traffic; and watching other aircraft; therefore this was clearly my duty as the FO to re-input the departure runway and double check the route.
ERJ-170 flight crew reported a track deviation and an airborne conflict shortly after takeoff from ATL when they failed to reprogram the FMS following a late runway change on taxi out.