B757-200
Air Traffic Control Fully Certified
Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors; ATC Equipment / Nav Facility / Buildings; Procedure
I had just combined both parallel finals at the ARM scope; and this was my first time working these positions with FUSION. Aircraft X; a B752; was on short final talking to the Tower. Aircraft Y; a PC12; was in trail just over 5 miles behind Aircraft X. I completed some work with traffic landing Runway 18L; and went to ship Aircraft Y to the Tower. It looked like I had just over 5 miles; but I was later told I only had 4.99. When Tower called to coordinate the break out for Aircraft Y; it looked like he was at a 5 mile final and Aircraft X was no longer observed. I was later told that the spacing was down to 4.86. FUSION made it very difficult to determine spacing because even targets firmly established on the localizer/final approach course wobbled back and forth. If I am forced to use FUSION; I will have to loosen my spacing in the final box.
M03 Controller described a loss of heavy jet separation event claiming FUSION equipment was a contributing factor.