Date: 201707
Local time of day: 1201-1800
Location: N90.TRACON, NY
Flight conditions: IMC
Weather elements / visibility: Rain; Thunderstorm
Light: Daylight
Aircraft: Medium Transport; High Wing; 2 Turboprop Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class E ZBW
ATC / advisory: Center ZBW; TRACON N90
Second aircraft: Light Transport; Low Wing; 2 Turbojet Eng
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness; Confusion
Second reporter function: Enroute
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance
Contributing factors: Airspace Structure; Company Policy; Manuals; Procedure; Weather
Primary problem: Manuals

Narrative: I was working the Mugzy position getting fed from ZBW with EWR arrivals as well as TEB and other satellite airport arrivals. Thunderstorms were popping up in the area and aircraft were reluctant to stay on the arrivals and wanted basically one track between multiple cells. ZBW interprets the N90/ZBW LOA (Letter of Agreement) which states 'they shall clear aircraft to 6000 feet when other traffic is not a factor' to mean that they can feed aircraft on top of one another at 7000 and 6000. This causes a multitude of problems as this specific situation the corporate jet; which needed to be beneath Aircraft X landing EWR; was actually climbed to 7000 and stacked directly above Aircraft X. There are multiple problems with this operation. The corporate jet needs to be lower than the EWR arrivals because of how the MUGZY sector is designed and the need to descend the satellite arrivals. This was never an option especially since all aircraft coming from ZBW wanted to stay on one specific track to thread the needle between the storms. After advising the ZBW controller I need them in trail not on top of one another an exchange occurs about thunderstorms being in the area and the LOA allows the aircraft to be fed at 7000 and 6000. Nowhere in the LOA is 7000 mentioned. As I stated above it says they shall clear the aircraft to 6000 when other traffic is not a factor. ZBW has been notified multiple times that N90 does not want the aircraft stacked and they refuse to comply because of how they interpret the LOA. If they leave the aircraft at 7000 the Mugzy controller then have to coordinate with ZBW to descend since there is nothing in the LOA which relinquishes control for descent on all arrivals handed off to N90. If a stacked feed was allowed wouldn't control also be given? A Front Line Manager; Controller; and Support Manager have all been on telecons with ZBW and explained why we cannot accept this type of feed and ZBW has refused to sign an updated LOA that clarifies the 'ambiguous' wording which they interpret to allow this type of feed. Furthermore after I reviewed the Falcon replay once I was relieved from position; it seems that this was almost intentionally done. When the handoffs were initiated both Aircraft X and Aircraft Y were at 6000 and Aircraft Y was approximately 4 miles in trail and showing the same speed. It wasn't until approximately 10 miles from the boundary that Aircraft Y was climbed to 7000 and accelerating. This put them both directly on top of one another for no reason at all. Getting ZBW to sign off on the updated LOA needs to be made a priority because situations like this are unacceptable. It has supposedly been being worked on for months now and has been elevated above the facility level. Whatever level is making the decision to fix this should be told it needs to be done immediately. Get ZBW to sign the updated LOA clarifying the procedure so they aren't able to 'interpret' how they please.


Second narrative: There was moderate and heavy precipitation covering 80 percent of the sector with large areas of extreme weather embedded inside. I had Aircraft X level at 7000 feet landing and a satellite airport arrival jet behind at 7000 feet. Approach took the hand off on Aircraft X and I transferred radio communications. They did not descend the satellite airport arrival so it was a factor with the arrival. The Letter of Agreement with Approach states: 'ARTCC must clear...satellite jet arrivals to 6;000 feet when other traffic at 6;000 feet is not a factor.' I was in compliance with the facility directives. Instead of calling me to tell me they needed some room between the aircraft they simply ignored the handoff. When I called them for the hand off; the controller told me that I am required to give those aircraft in trail. He did take a point out on the jet but forced me to issue a 360 degree turn. There was severe weather to the west of course and other arrival traffic at the same altitude to the east of his course. The controller at N90's decision to ignore the aircraft's hand off attempt until I called created a very unsafe situation with the weather and other traffic. If Approach wants all traffic on the airway in trail at 6000 feet; the Standard Operating Procedure Manual needs to be rewritten to reflect that.


Synopsis: N90 TRACON Controller and ZBW ARTCC Controller reported disagreeing on the interpretation of the facility directives regarding handoffs from the Center to Approach Control.