Date: 201306
Local time of day: 1801-2400
Location: A90.TRACON, NH
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
ATC / advisory: TRACON A90
Second aircraft: B757-200
Reporter organization: Government
Reporter function: Departure; Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Other / Unknown; Situational Awareness
Anomaly: ATC Issue All Types
Detector: Person Air Traffic Control
Result: General None Reported / Taken
Contributing factors: Human Factors; Airport; Procedure
Primary problem: Procedure

Narrative: We were running parallel runway operations to Runway 4R and 4L and I was the final 1 Controller working 4R. I turned Aircraft Y onto the final but was slightly behind the aircraft matched up for 4L by the time Aircraft Y made the turn. Aircraft X was landing 4L with my aircraft in sight; however I also needed to get Aircraft X in sight since I was now behind. Aircraft Y did see that aircraft and was told to maintain visual separation with them as well. They were paired up evenly on final and once inside the FAF both aircraft slowed to their specific approach speeds. Aircraft Y approach speed was faster than Aircraft X and pulled ahead slightly and remained ahead for the duration of the approach. I feel the 7110.65 may need to be revised to adequately cover visual separation. Both aircraft had each other in sight; however it is stated to be illegal for a wake turbulence category aircraft to overtake the lesser category aircraft. The overtake was 0.25 miles and the aircraft could still clearly see each other. The A319 [Aircraft X] knew that the parallel traffic was a B752 [Aircraft Y] and was aware of the wake turbulence situation. Given both aircraft still saw each other; I don't feel this is a safety situation. Based off the current rules; the B752 should have had the approach clearance cancelled and resequenced; but I felt that action would be even less safe than allowing the approach to continue. Runway 4L threshold is displaced further northeast than 4R so even though the B752 was slightly ahead; the A319 was still higher on the glide path to 4L than the wake of the B752 because the glide path remains higher due to the displaced landing zone. Aircraft X also responded to a TCAS RA; although no action was taken. Given that an RA occurred because of aircraft proximity; maybe parallel runway operation procedures need to be amended. Maybe staggering the arrivals instead of pairing them is a better option. That way; an overtake will not occur nor will RA's. If something like that is implemented; the arrival rates will most likely change as well; which is also a major factor. The system demands us to run closely spaced parallel traffic to efficiently run the volume of traffic at busy peak hours; however an occurrence like this one is categorized as a major violation which I don't feel it should be. I don't feel either aircraft was ever placed into an unsafe situation during any phase of flight in our airspace.




Synopsis: A90 Controller described a technical loss of separation event during simultaneous parallel runway operations involving heavy separation; the reporter recommending possible revised procedures.