Date: 201604
Local time of day: 1201-1800
Location: DFW.Airport, TX
Light: Daylight
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B DFW
ATC / advisory: TRACON D10; Tower DFW
Second aircraft: EMB ERJ 135 ER/LR
Reporter organization: Government
Reporter function: Other / Unknown
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Time Pressure; Distraction; Situational Awareness; Communication Breakdown
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: DFW Weather MVFR; low layer reported at 900 feet; I was getting arrivals in sight at approximately a 2 mile final. Visibility was excellent below the clouds. Aircraft Y was on final; approximately 10 miles out when I noticed that they were more than 100 knots faster than Aircraft X; but still separated by more than 5 miles (estimated). The Final Monitor Controller initiated coordination with me asking if we (the tower) had the two aircraft in sight and could provide visual separation. I replied that we could not see the second aircraft. Final Monitor took no further action.The Local West (LW) controller and I were discussing the situation when another controller plugged in to Local to relieve the LW controller. LW commented something to the effect 'Oh well; I'll just file a report after July'. It is well known that the LW controller intends to retire. Prior to working LW; the controller had been working Ground West and was engaged in a conversation with the Flight Data West controller and Front Line Manager (FLM). He stated that '184 (referring to the pay cap) and as little responsibility should be all federal employee's goal'.After the LW controller was relieved and went downstairs; I reported the event to the FLM who; I believe; was monitoring the position via wireless headset although he was busy on the computer with something and had another controller at his desk so he may not have been fully aware of what was going on. Also; since he is monitoring the LW position and not the LAW position; he would not have heard the coordination between the final monitor and me.In hindsight I wish that I had directly instructed the LW controller to break out Aircraft Y rather than attempt to influence his actions by asking him if he had it. Sure; D10 could have done a better job; but we had a chance to ensure safety too but we chose to let it go.The LW controller should be referred to Professional Standards and if they are not able to resolve the attitude issue; this controller should be removed from ATC duties until he retires. Training should be developed at DFW and D10 that helps to put the emphasis back on safety and less on efficiency. Professional Standards training for the whole facility to re-instill a professional attitude that reflects the importance of our job.




Synopsis: DFW Tower Controller reported of a loss of separation on final due to speed overtake and the lack of timely go-around instructions.