Date: 201501
Local time of day: 0601-1200
Location: DAL.Airport, TX
Flight conditions: VMC
Light: Daylight
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B DAL
ATC / advisory: TRACON D10; Tower DAL
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Distraction
Anomaly: Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Detector: Automation Aircraft RA; Person Flight Crew
When detected: In-flight
Result: Flight Crew FLC complied w / Automation / Advisory
Contributing factors: Airport; Environment - Non Weather Related
Primary problem: Ambiguous

Narrative: I was Pilot Monitoring (PM). Captain was Pilot Flying (PF). Weather conditions were clear with unrestricted visibility. DAL was landing north (Runways 31L/R). After check-in with Regional Approach Control; we were cleared direct to MYLES fix; instructed to join the DAL Runway 31L Localizer final and cleared to descend to 3;000 feet MSL. We complied with all instructions. Approaching MYLES; we reported the [airport] and Runways 31L/R in sight and were cleared a Visual Approach to Runway 31L. We continued on the ILS Runway 31L Localizer as a backup to the Visual; and continued descent to 2;200 feet MSL to intercept the Runway 31L glideslope at JAKID. As we continued; Regional Approach informed us of traffic (a Learjet) at 3;000 feet MSL on a right base for DAL Runway 31R. We initially responded we were searching for the called traffic and continued in-bound on the approach and continued slowing and configuring the aircraft. A few moments later; we both visually acquired the Learjet traffic and reported 'Learjet traffic; in sight' to Regional Control. Regional Control acknowledged our report and instructed us to contact LOVE Tower. Upon initial check-in with LOVE Tower; we reported we were on the Visual to Runway 31L and had the Learjet traffic to Runway 31R; in sight'. LOVE Tower cleared us to land on Runway 31L. Approaching JAKID; Runway 31L glideslope intercept (GSI); we received a TCAS TA; which correlated to the Learjet on our right side landing Runway 31R. Shortly after beginning our final descent on the glideslope/glidepath to Runway 31L; we received a descend TCAS Resolution Advisory (RA); again correlating to the Learjet traffic on our right side; on final to Runway 31R. Captain/PF; complied with the RA; disconnected the autopilot; increased the rate of descent to approximately 1;000 fpm; in compliance with the TCAS RA directions; as we finished configuring the aircraft for landing. At approximately; 1;500 feet MSL; the TCAS announced 'Clear of conflict'; and the Captain/PF decreased the descent rate to re-intercept a more normal three degree final ILS glideslope/glidepath. We reported complying with the TCAS RA to LOVE Tower; when it occurred; and LOVE Tower asked for our intentions. We did not receive any EGWPS cautions or warnings during compliance with the TCAS descend RA.We could have planned to intercept the glideslope/glidepath at a different altitude; we could have intercepted at 3;000 feet MSL and the Learjet traffic to Runway 31R at 2;200 feet MSL. ATC/Regional Control could have directed some lateral offset to aircraft joining a parallel final; 1 NM trail offset. Aircraft joining a parallel final with aircraft established on the parallel final; should attempt all means of achieving some 'offset' vertical (altitude); lateral (ease onto the final/runway centerline from their side of final); and/or establish plus maintain some horizontal offset (1NM offset trail).




Synopsis: A flight crew on final for the left parallel runway received a TCAS RA with respect to a Learjet on a base leg to the right runway at Dallas Love. The runways are about 1/2 mile apart.