Narrative:

Aircraft X; E190; was lead aircraft followed by aircraft Y; B752; trailing aircraft. At transfer of control point both aircraft were doing same assigned speed from N90. As aircraft X approached FAF he began slowing to land and aircraft Y continued at assigned speed to FAF. The compression on final began and I asked aircraft Y to slow to final approach speed (and he responded); as this was happening the other local (LC2) working the departure runway (inboard runway) 04L; gave me multiple runway crossings of 04L @ fb; F 2X; and G. Due to the IFR weather conditions and low visibility we were in and out of being allowed to have 2.5 miles on final (as opposed to 3) dependent on if we could see the runway exits. At the time of aircraft X landing; I could see the runway (runway) exits so 2.5 miles was acceptable; however as I was completing the coordination to cross 04 left with multiple aircraft; aircraft Y got to within 2.25 miles of aircraft X (as he touched down). Aircraft X exited at the midfield F; and aircraft Y landed without issue behind him. The transfer of control for arrivals on 04R is 8NM; however in many cases we do not get them until just at 8 miles or inside; this doesn't normally allow for enough time on IFR weather days to slow aircraft to account for compression on final within the FAF. N90 routinely assigns speed to the FAF and runs a tight final so unless we are given control at 8 miles (with at least a chance to slow someone) there is no way to accomplish the task. To complicate things further we have to coordinate/accomplish runway crossings at the same time with another controller which takes up a lot of time on frequency during which most separation is lost. There is probably not much we could change to avoid this except allow for proper transfer of control or have N90 stop assigning the same speed to all aircraft because when they slow inside FAF compression is then inevitable. If the lead aircraft is going 180 to FAF; then the trailing should be 170 to build the space they will lose; in IFR conditions and considering aircraft type; characteristics; and wake turbulence.

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Original NASA ASRS Text

Title: JFK local controller reported loss of separation on final approach during IFR conditions while coordinating runway crossings; noting compression of aircraft spacing on final and approach control speed control prior to handoff as contributors.

Narrative: Aircraft X; E190; was lead aircraft followed by Aircraft Y; B752; trailing aircraft. At transfer of control point both aircraft were doing same assigned speed from N90. As Aircraft X approached FAF he began slowing to land and Aircraft Y continued at assigned speed to FAF. The compression on final began and I asked Aircraft Y to slow to final approach speed (and he responded); as this was happening the other Local (LC2) working the departure runway (inboard runway) 04L; gave me multiple runway crossings of 04L @ FB; F 2X; and G. Due to the IFR weather conditions and low visibility we were in and out of being allowed to have 2.5 miles on final (as opposed to 3) dependent on if we could see the runway exits. At the time of Aircraft X landing; I could see the runway (RWY) exits so 2.5 miles was acceptable; however as I was completing the coordination to cross 04 L with multiple aircraft; Aircraft Y got to within 2.25 miles of Aircraft X (as he touched down). Aircraft X exited at the midfield F; and Aircraft Y landed without issue behind him. The transfer of control for arrivals on 04R is 8NM; however in many cases we do not get them until just at 8 miles or inside; this doesn't normally allow for enough time on IFR weather days to slow aircraft to account for compression on final within the FAF. N90 routinely assigns speed to the FAF and runs a tight final so unless we are given control at 8 miles (with at least a chance to slow someone) there is no way to accomplish the task. To complicate things further we have to coordinate/accomplish runway crossings at the same time with another controller which takes up a lot of time on frequency during which most separation is lost. There is probably not much we could change to avoid this except allow for proper transfer of control or have N90 stop assigning the same speed to all aircraft because when they slow inside FAF compression is then inevitable. If the lead aircraft is going 180 to FAF; then the trailing should be 170 to build the space they will lose; in IFR conditions and considering aircraft type; characteristics; and wake turbulence.

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.