Narrative:

During this event; I was the controller working the arrival 1 and arrival 2 sectors. During this time; we had 2 tfrs active because of the [dignitary] visiting the area. Traffic was very heavy and complex as I was sequencing aircraft to [parallel runways]. I had heavy base leg and downwind traffic at the time. I had so many aircraft on frequency that the number of aircraft checking on my frequency with very long and wordy initial contacts made if very frustrating and difficult for me to make timely transmissions at times. I had base leg traffic and downwind traffic going to both runways. I got behind when at the very last second and in a very untimely fashion; I was told to assign as aircraft X; a general aviation aircraft; runway xyz when it was already assigned runway xya by the feeder controller.I was told by the front line manager (flm) to make this reassignment when then the aircraft X was only 15 miles northeast of [the] airport; which is a very untimely decision. This decision had to be made because; due to the [dignitary] tfrs; no general aviation aircraft were allowed to go to runway xya; only air carriers and medevac flights. Nobody realized this until the traffic management coordinator approached the supervisor and made it clear. This created a wake turbulence situation between the aircraft X and a large category aircraft in front of him. This last second change increased the complexity of this scenario because the base leg and downwind feeds were of a very high volume. Normally AR1 and AR2 are split in a much timelier fashion; but on this occasion; the supervisor did not split the sectors when it was needed. I had never seen these combined sectors so busy without being split off. The supervisor later approached me and apologized for putting me in this predicament.when this 'push' came to an end; there were still many aircraft in the arrival sectors. I was very distracted and frustrated with the situation which was forced on me by the supervisors. All aircraft were sequenced and cleared for a visual approach. I had several wake turbulence situations during this session which also took a lot of attention and time and trailing aircraft were not getting the preceding traffic in sight dependably. I lost in trail separation between aircraft Y and aircraft Z which were both already cleared for a visual approach to runway xya. Closest proximity was 1.93 NM and 100 feet. Aircraft Z had a very large overtake which caused the spacing; which was adequate when I cleared him for the visual approach; to decrease very rapidly. I did not see this situation because of data block overlap on my scope. When I finally saw the unsafe situation and attempted to use visual separation; separation had already been lost. I attempted to get aircraft Z to get aircraft Y in sight and use visual separation incorrectly. Aircraft Z did get aircraft Y in sight; and I instructed aircraft Z to 'follow' the traffic to runway xya. The pilot of aircraft Z agreed to do so. I then changed my mind because I believed it was an unsafe situation. I immediately cancelled aircraft Z approach clearance and sequenced him successfully. The sectors were finally split after I had the error.I recommend that supervisors pay more attention to rapidly developing situations that are made more complex by tfrs. These two sectors are always split off for much less traffic than I had during this period. I recommend that supervisors do not wait until the last minute to make decisions. Sectors should be split before workload becomes too overwhelming.

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Original NASA ASRS Text

Title: D10 TRACON Controller reported working two busy combined sectors and allowed in trail spacing between two to decrease to less than required spacing.

Narrative: During this event; I was the controller working the Arrival 1 and Arrival 2 sectors. During this time; we had 2 TFRs active because of the [dignitary] visiting the area. Traffic was very heavy and complex as I was sequencing aircraft to [parallel runways]. I had heavy base leg and downwind traffic at the time. I had so many aircraft on frequency that the number of aircraft checking on my frequency with very long and wordy initial contacts made if very frustrating and difficult for me to make timely transmissions at times. I had base leg traffic and downwind traffic going to both runways. I got behind when at the very last second and in a very untimely fashion; I was told to assign as Aircraft X; a General Aviation aircraft; Runway XYZ when it was already assigned Runway XYA by the feeder controller.I was told by the Front Line Manager (FLM) to make this reassignment when then the Aircraft X was only 15 miles northeast of [the] airport; which is a very untimely decision. This decision had to be made because; due to the [dignitary] TFRs; no General Aviation aircraft were allowed to go to Runway XYA; only air carriers and medevac flights. Nobody realized this until the traffic management coordinator approached the supervisor and made it clear. This created a wake turbulence situation between the Aircraft X and a large category aircraft in front of him. This last second change increased the complexity of this scenario because the base leg and downwind feeds were of a very high volume. Normally AR1 and AR2 are split in a much timelier fashion; but on this occasion; the Supervisor did not split the sectors when it was needed. I had never seen these combined sectors so busy without being split off. The Supervisor later approached me and apologized for putting me in this predicament.When this 'PUSH' came to an end; there were still many aircraft in the Arrival sectors. I was very distracted and frustrated with the situation which was forced on me by the Supervisors. All aircraft were sequenced and cleared for a Visual Approach. I had several wake turbulence situations during this session which also took a lot of attention and time and trailing aircraft were not getting the preceding traffic in sight dependably. I lost in trail separation between Aircraft Y and Aircraft Z which were both already cleared for a Visual Approach to runway XYA. Closest proximity was 1.93 NM and 100 feet. Aircraft Z had a very large overtake which caused the spacing; which was adequate when I cleared him for the visual approach; to decrease very rapidly. I did not see this situation because of data block overlap on my scope. When I finally saw the unsafe situation and attempted to use visual separation; separation had already been lost. I attempted to get Aircraft Z to get Aircraft Y in sight and use visual separation incorrectly. Aircraft Z did get Aircraft Y in sight; and I instructed Aircraft Z to 'follow' the traffic to runway XYA. The pilot of Aircraft Z agreed to do so. I then changed my mind because I believed it was an unsafe situation. I immediately cancelled Aircraft Z approach clearance and sequenced him successfully. The sectors were finally split after I had the error.I recommend that Supervisors pay more attention to rapidly developing situations that are made more complex by TFRs. These two sectors are always split off for much less traffic than I had during this period. I recommend that Supervisors do not wait until the last minute to make decisions. Sectors should be split before workload becomes too overwhelming.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.