ZBW Capping & Tunneling Plan

CAPPING PLANS

During severe weather season, air traffic that is deviating (or has been rerouted) for thunderstorm avoidance may cause complexity and volume issues in numerous ZBW sectors. Subsequently, the Boston Center Traffic Management Unit may implement various Capping and Tunneling Traffic Management Initiatives (TMIs). This Capping and Tunneling Plan describes the coordination necessary to accomplish these initiatives successfully.

For this plan "Capping" refers to restricting departure aircraft at a lower altitude until a point in space beyond the constrained area. Beyond that point these capped flights can safely be climbed to their requested altitude. ZBW TMU utilizes two capping initiatives: Terminal Capping and En route Capping.

For this plan "Tunneling" refers to the practice of descending arrival aircraft sooner than normal and continuing to their destination airport below the constrained area.

ZBW sector complexity, workload, weather, or other factors may necessitate the use of capping turbojet aircraft from eastern ZBW airports at or below (AOB) 10,000ft to New York metropolitan area airports. The city pairs and routes of flight are captured in the SERBOS1 national play. These jet aircraft that would have entered ARTCC airspace at or above (AOA) 11,000 ft will now transit through Yankee TRACON (Y90) and Providence TRACON on routing normally reserved for props/turboprops. This higher volume may result in a departure sequencing program with an associated call-for-release.

Enroute Capping

West Plan:

During a large thunderstorm event, rerouted flights may cause volume issues in ZBW’s central and western high-altitude sectors. One mitigation strategy to relieve pressure on these impacted sectors is to cap westbound departures from the Boston and New York areas at or below FL260, typically to western NY State, Toronto, or the upper Mid West. During a Severe Weather Avoidance Plan (SWAP) event, ZBW TMU will work with the Area supervisors to identify and coordinate the need to cap New York and Boston-area departures.

The GREKI 1 national play is an example of one such capping initiative, where traffic from the New York metro area cannot proceed via N90’s normal west gates to CYYZ, KROC, KBUF, and KSYR. This traffic is moved through ZBW over GREKI, capped AOB FL220 to their respective destinations.

Traffic from BOS or BED routed over HYLND may be capped AOB FL260, or FL220, to avoid entering high altitude sectors that are dealing with other SWAP-related traffic from other origins.

North Plan:

During a large thunderstorm event, rerouted flights may cause sector volume issues in ZBW’s central and western high-altitude sectors around the Albany, NY area. One mitigation strategy to relieve pressure on these impacted sectors by capping GREKI departures from the New York metropolitan area destined to CYUL, CYOW, KBTV, KPBG, KOGS, and other northern ZBW destinations AOB FL230.

Maritime Capping

Two ZBW high-altitude sectors over Maine work a large amount of international traffic to/from the US and Europe. Periodically, these sectors may require a capping play to reduce enroute sector volume or complexity via the form of capping departures to/from the Canadian Maritime provinces of Nova Scotia, New Brunswick, Prince Edward Island, and Newfoundland.

This traffic is destined to or originating in Moncton or Gander ACCs (including, but not limited to, CYHZ, CYSJ, CYFC, CYQI, CYQM, CYYG, CYQX) and will be capped AOB FL280 until reaching Canadian airspace on the other side of ZBW airspace.

Impact on Fuel

Since flying longer distances at lower altitudes burns more fuel, coordination with the aircraft operators should be accomplished prior to implementing either Capping Plan so that extra fuel can be flight planned for each departure. Applicable ATCTs should also ask the dispatchers to remind the pilots to not ask for higher during these Capping Initiatives. Then, thorough coordination needs to be accomplished between the towers, TRACONs, and each affected ZBW sector. TMU will also need to coordinate with adjacent facilities if the flights will remain capped until a point inside their airspace.

Tunneling Plans

Tunneling Plan Description:

The practice of tunneling aircraft below constrained airspace may occur during periods of heavy enroute volume and/or complexity.

East Plan:

During certain scenarios, ZBW will descend BOS-area arrival aircraft sooner than normal below a constrained area, typically between SYR and ALB, AOB FL230. This allows ZBW to reduce congestion particularly in high sectors. In certain scenarios, ZBW may need to tunnel New York TRACON (N90) arrivals from adjacent facilities in the same vicinity between SYR and ALB, AOB FL230. Tunneling may sometimes occur as west as GEE or CFB by ZOB, AOB FL310 or FL270 depending, so as to descend below congested high-altitude ZBW airspace/traffic.

North Plan:

Arrivals to CYUL, CYMX, CYHU, CYQB, Northern New York state and Northern New England from ZNY may be descended AOB FL230 prior to ALB, in the vicinity of IGN. This would also be implemented to avoid congested high-altitude sectors, particularly on nights with severe weather in ZNY and ZBW.

At ZBW, tunneling is typically accomplished on a more tactical basis than capping procedures, but if impacts are expected to be more than minimal, ZBW TMU will accomplish necessary coordination with affected facilities and users.

Maritime Tunneling

Two ZBW high-altitude sectors over Maine work a large amount of international traffic to/from the US and Europe. Periodically, these sectors may require a tunneling play to reduce enroute sector volume or complexity via the form of tunneling aircraft to/from the Canadian Maritime provinces of Nova Scotia, New Brunswick, Prince Edward Island, and Newfoundland.

This traffic is destined to or originating in Moncton or Gander ACCs (including, but not limited to, CYHZ, CYSJ, CYFC, CYQI, CYQM, CYYG, CYQX) and will be tunneled AOB FL280 prior to entering ZBW airspace.

Impact on Airspace:
The routes and distances for all Capping and Tunneling procedures will need to be determined dynamically for each weather/sector complexity scenario. These capping and tunneling procedures may add significant volume and complexity to our low altitude sectors that provide airport control at many airports, therefore additional TMIs (i.e. miles-in-trail) may be needed to manage the additional volume in those sectors.

Internal/External Facility Impact:
ZBW impact depends on the specific area and sectors that are experiencing volume and complexity issues due to severe weather reroutes. Therefore, additional mile-in-trail (MIT) restrictions may be implemented to mitigate volume concerns.

Additionally:

In addition to the coordination described above, all plans to cap or tunnel should also be briefed on all ATCSCC planning telcons. Capping and tunneling with other facilities within ZBW will be done on a tactical basis with the tower and ZBW TMU.