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. The Capping and Tunneling Plan is just an example of some TMIs that can occur on SWAP nights, and puts to paper TMIs we have been performing here at ZBW for years.

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 light 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.

En-route Capping

West Plan:

During a large thunderstorm event rerouted flights may cause volume issues in numerous ZBW high altitude sectors. One mitigation strategy to relieve pressure on these impacted sectors is to cap departures from the Boston and New York areas at or below FL260. 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 N90s 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, BED, or other A90-internal airports 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.

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 Plan Description:

The practice of tunneling aircraft below constrained airspace may occur during periods of heavy en route 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 as west as GEE or CFB in ZOB, AOB FL310 or FL270 depending, to descend below congested high-altitude ZBW airspace and other 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.

Note: The North Tunneling Plan and East Tunneling Plan cannot be run concurrently with a GREKI 1 or GREKI 2 Play due to traffic conflictions.

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 will 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.