DA42 Twin Star
Air Traffic Control Fully Certified
Human-Machine Interface; Situational Awareness
ATC Issue All Types
Air Traffic Control Issued New Clearance
ATC Equipment / Nav Facility / Buildings; Procedure
Low ceilings; pilot training; poor RADAR updates due to new Fusion system. While working position; I had numerous IFR practice approaches along with a few itinerant jet arrivals. While vectoring Aircraft X for sequence for the ILS 7L; I had to break Aircraft X off the approach due to an over take on the aircraft ahead of him. I had Aircraft Y on a downwind to follow Aircraft X. I had issued Aircraft Y a base leg turn but RADAR still showed that Aircraft Y was on the downwind and it appeared due to the RADAR lag in Fusion that Aircraft Y had not begun the turn or was turning at a very slow rate. I issued Aircraft X a 050 heading which would have given me course divergence on both the aircraft on final and Aircraft Y. however again due to the lag in updates under Fusion; I noticed that Aircraft Y went from a downwind track to a base leg track with no updates in between which made it impossible to know exactly where Aircraft Y [was] due to this lag in updates. This is a very serious problem with Fusion. You cannot anticipate an aircraft's rate of turn which allows you to determine weather or not the aircraft is turning or how fast or slow the aircraft is turning. This is a very critical element at DAB due to the numerous training aircraft that we work. We quite often have to deal with student pilots that read back our instructions but do not follow them or are very slow in doing so. Discontinue the use of Fusion until all aspects of the system have been corrected including the ADSB equipment required in the aircraft that make the system work. Currently no aircraft in our area are equipped with the correct version of ADSB.
DAB Controller voiced concern regarding the time lag in the Fusion RADAR system; making the identification of aircraft positions less than desired.