Revised ATS route structure over the Irish Sea

Revised ATS route structure over the Irish Sea (Isle of Man and Antrim Sectors) Airspace Change Proposal Prepared by CPW Peer-reviewed by JB NATS Future ATM & Policy - Airspace Change Assurance Team Issue 1.0 29 th March 2017

Table of contents Table of contents 2 References 4 1 Introduction 5 1.1 The Isle of Man and Antrim Airspace Sectors 5 2 Justification and Objectives 6 2.1 Justification 6 2.2 Objectives 6 2.3 PC Antrim 6 2.4 Alignment with the CAA s Future Airspace Strategy (FAS) Principles 6 2.5 Enabler for network changes in Manchester TMA and Scottish TMA 6 3 Current Airspace 7 3.1 Description 7 3.2 Modernising the air route infrastructure 7 3.3 Revision of minimum radar separation 7 3.4 Traffic Figures & Aircraft Types for the year 2016 9 3.5 Traffic Forecasts 10 3.6 Operational Efficiency, Complexity, Delays & Choke Points 10 3.7 Environmental Issues 11 3.8 Safety 11 4 Proposed Airspace 12 4.1 Requirements 12 4.2 What Would Not Change Under the Proposal 12 4.3 What Would Change Under the Proposal 12 4.4 RNAV equipage 16 4.5 Route allocation 16 5 Impacts of Airspace Change 17 5.1 Net Impacts Summary for Proposed Routes 17 5.2 Noise, tranquillity, stakeholders on the ground, air quality, biodiversity 17 5.3 CO 2 emissions & fuel burn 17 5.4 Delays to air traffic 18 5.5 General Aviation (GA) airspace users 18 5.6 Impact on Aviation Safety, including safety analyses and complexity. 18 5.7 Non-NATS Units Affected by the Proposal 19 5.8 IAA - UK-Ireland Functional Airspace Block (FAB) Partners 19 5.9 MoD including BAE Systems 19 5.10 Commercial Air Transport Impact & Consultation 19 IOM & Antrim Airspace Change Page 2

5.11 Economic Impact 19 5.12 Sponsoring Unit Training Requirements 20 6 Analysis of options 21 6.1 Introduction 21 6.2 Design Principles and Envelope discussion 21 6.3 Design Options General 21 6.4 Design Options - Direct Route Airspace 23 7 Airspace Description Requirement 25 8 Supporting Infrastructure & Resources 26 9 Operational Impact 27 10 Airspace & Infrastructure Requirements 28 11 Environmental Requirements 30 12 Appendix A: List of LoAs to update 37 13 Appendix B: List of Proposed Amendments to the AIP 38 IOM & Antrim Airspace Change Page 3

References Reference 1: Consultation Document. Reference 2: Feedback Report Reference 3: CAP725 CAA Guidance on the Application of the Airspace Change Process. Reference 4: CAP1385 PBN Enhanced Route Spacing Guidance Reference 5: Evidence supporting the use of CAP1385 in an en-route environment (to follow early April) Reference 6: Evidence supporting the use of 2nm minimum CAS containment for RNAV1 environment Reference 7: Project Safety Assurance and Human Factors Plan Reference 8: Project Safety Hazard Identification and Human Error Safety Assurance Process Reference 9: Route Design Analysis Report Reference 10a, 10b, 10c: (a) Environmental and ATC Conflict Fast-Time Sim analysis report (b) Delay cost analysis report (c) Benefits summary report, combining (a) and (b). Reference 11: Airspace Design Definition ADD Reference 12: Chart of the region (switchable layers) Reference 13: Draft AIP submission (from standard CAA Excel sheet for WGS84 coordinate & bearing/distance validation) Reference 14: Draft Training Plan Reference 15: Air Traffic Project Safety Assessment APSA (to follow pre-implementation) Reference 16: Report on RNAV1 coverage for the Irish Sea region Reference 17: Validation Simulation Report (to follow early/mid-may) Reference 18: Zip file of emails from senior aerodrome managers giving NATS permission to truncate certain STARs IOM & Antrim Airspace Change Page 4

1 Introduction NATS is proposing changes to the ATS route structure over the Irish Sea. We propose to introduce a system of RNAV1 routes, for flights in the Isle of Man and Antrim Sectors of NATS Prestwick Area Control Centre. This is part of a phased delivery of a wider programme agreed with our customers under the NATS Long Term Investment Plan (LTIP). By taking advantage of modern navigation performance known as RNAV1, routes can be spaced more closely than the legacy route structure which is based on VOR and NDB radio beacons. This will allow enhanced systemisation and enable more efficient use of the airspace. We consulted with aviation stakeholders from 4 th July to 30 th August 2016 and made changes to the design based on their feedback (Refs 1 & 2). If the proposal is approved by the CAA, implementation of the airspace change is planned for 09 Nov 2017. 1.1 The Isle of Man and Antrim Airspace Sectors NATS Prestwick Centre (PC) manages all en-route air traffic in the northern half of the UK. The PC Isle of Man (IOM) sector of airspace handles much of the air traffic between Dublin and the UK/Europe, and also some of the UK s transatlantic arrivals/departures. PC Antrim sector handles all traffic to/from Northern Ireland, and traffic routing from western Scotland/Scandinavia to Eire. The current network is operating at capacity in the IOM sector. This proposal would provide additional capacity in the IOM sector, reducing the likelihood of delays in the region. It would also modernise this part of the network to take advantage of newer technology available on modern aircraft. PC Antrim PC IOM Figure 1 Prestwick Centre s Isle of Man (FL45-FL285) and Antrim (FL45-FL255) sectors. (Only the areas of PC IOM and PC Antrim sectors relevant to this proposal are shown.) PC IOM and PC Antrim sectors lie beneath PC Rathlin, Swanwick Centre s Sector 7 (SWN S7) and Sector 4 (SWN S4), these are not shown here due to chart complexity. There are also interfaces with the adjoining IAA Dublin and Shannon units, and other SWN/PC sectors. IOM & Antrim Airspace Change Page 5

2 Justification and Objectives 2.1 Justification Capacity limitations in the IOM sector often result in the application of short-term ATC measures 1 (STAMs). A typical example is where Dublin declares dual runway operations, which enables them to expedite first rotation departures. The majority of these departures route through IOM sector in the climb to cruising levels. This situation quickly leads to the IOM sector reaching maximum capacity, which then result in STAMs being required at Dublin. If traffic continues to increase as forecast (or above), increasing levels of delay in the IOM sector are predicted. NATS is obliged through its operating licence to avail on a continuing basis any reasonable level of overall demand and it specifies this in terms of the provision of core services. The delays justify the necessity to make changes to the airspace to increase ATC capacity. 2.2 Objectives The current Monitor Value 2 (MV) for the IOM sector is 43. The objective of this proposal is to increase this by 10%, to 47. This would enable the region to operate with fewer flow restrictions being applied and hence less delay. We would achieve this objective by: a. Increasing the number of parallel east-west routes over the Irish Sea and the number of routes oriented northwest-southeast linking Northern Ireland and the mainland via the Isle of Man, increasing ATC capacity; and b. Optimising the route spacing in accordance with updated guidance from the CAA taking advantage of modern navigation performance; and We minimised the additional controlled airspace (CAS) required to contain these routes. 2.3 PC Antrim PC Antrim interacts very closely with the adjacent PC IOM. The proposed route changes to PC Antrim are required to deliver the increased ATC capacity and improved Monitor Value in PC IOM. PC Antrim sector would naturally benefit, but the specific justification for the changes to Antrim remain the forecast delay reduction in the adjacent IOM sector. 2.4 Alignment with the CAA s Future Airspace Strategy (FAS) Principles A contiguous design of routes in these sectors would improve systemisation. Systemisation is the aim of most future airspace designs. The CAA s Future Airspace Strategy (FAS) is the UK s strategy for modernising the air route infrastructure. 2.5 Enabler for network changes in Manchester TMA and Scottish TMA The proposed IOM & Antrim changes are part of the Prestwick Lower Airspace Systemisation (PLAS) programme of NATS LTIP changes. The changes described herein serve as an enabler for further changes planned to the ATS network in the Manchester and Scottish TMAs. These changes will bring further efficiencies across the network. 1 STAMs include Minimum Departure Intervals (MDIs), Miles in Trail (MIT), Airfield Reasonable Departure Separation (ARDS), Average Departure Interval (ADI), all of which are measures that can be applied to regulate the flow of traffic departing from airports. 2 Monitor Value is a guide value for the ATC supervisor. The greater the MV, the greater the hourly throughput of the sector under normal conditions, before the supervisor considers taking measures to regulate the anticipated flow. IOM & Antrim Airspace Change Page 6

3 Current Airspace 3.1 Description The charts on the next page illustrate the current ATS route structure from a flight-planning point of view, and also how the airspace volume is currently used in practice. Parallel routes are common in the ATS route network. PC IOM currently has a structure incorporating three east-west parallel ATS routes which are separated by 12nm (see Figure 2 on page 8 (U)L70, (U)L975 and (U)Y124). Currently ATC uses these routes for flight planning and navigation. When climbing and descending, conflicting aircraft are often tactically vectored off two of the flight-plan ATS routes: (U)L70 and (U)L975, creating sets of offset parallel tracks within the existing CAS volumes (see Figure 3). Traffic using (U)Y124 is generally left on its own navigation. A similar structure occurs in the airspace between BEL VOR and WAL VOR, this is also managed tactically by ATC to increase efficiency (see Figure 3 on page 8). This tactical vectoring requires the controller to be constantly monitoring the aircraft headings to ensure radar separation is maintained between all flights a relatively intense task - but it makes far more efficient use of the available airspace. Parallel vectoring means more aircraft can be simultaneously climbed and descended to their desired levels than if all flights follow the centre of the ATS routes, in trail. The proposal would provide the greater efficiency of systemised parallel routes. By using systemised routes rather than vectoring, controller workload will be reduced which will in turn reduce the likelihood of error and increase the capacity of the airspace. In order to achieve this objective two things are required: modernising the air route infrastructure, and revising the minimum radar separation. 3.2 Modernising the air route infrastructure As per the consultation document and feedback report, we propose to establish RNAV1 routes in this region, with updates to CAS volumes at the same time (a small increase in Class C CAS is required in a non-contentious region). Most commercial aircraft already have the ability to conform to RNAV1. The equipage rate for aircraft which are RNAV1 capable in the IOM sector is currently 94% 3. The CAA s Future Airspace Strategy (FAS) 4 also recommends that the ATS route network is improved, to take advantage of available technology such as RNAV1. 3.3 Revision of minimum radar separation In order to comply with CAP1385 requirements, PC implemented 3nm radar separation 5 on the 2 nd March 2017. Specifically for this proposal, 3nm radar separation applies in the IOM sector up to FL285, and in the Antrim sector up to FL255. MATS Part 2 procedures ensure appropriate separation is maintained during the transition between 3nm and 5nm environments, and adjacent ANSPs/non-PC sectors. 3 NATS PBN equipage survey Jan-Feb 2017, % of airframes for flights through the IOM sector. 4 Civil Aviation Authority, Future Airspace Strategy for the United Kingdom 2011 to 2030 www.caa.co.uk/fas 5 Between PC controllers under specified conditions in specified areas (details not included here). IOM & Antrim Airspace Change Page 7

Figure 2 IOM and Antrim existing RNAV5 routes & CAS Figure 3 IOM and Antrim existing tactical vectoring system used by controllers IOM & Antrim Airspace Change Page 8

3.4 Traffic Figures & Aircraft Types for the year 2016 The following data tables describe the aircraft types using the existing RNAV5 ATS routes within the region. The tables below detail the most frequent aircraft types using each route. The aircraft types covering 90% or more of the flights using each route are shown. (U)L70 UNDUX-BAGSO (U)L975 LIFFY-LYNAS 63847 flights in 2016 74998 flights in 2016 AC Type Count Percent AC Type Count Percent B738 22257 34.9% B738 24692 32.9% A320 9805 15.4% A320 12578 16.8% AT76 3765 5.9% AT76 4081 5.4% B763 2877 4.5% B763 3630 4.8% A321 2193 3.4% A332 3032 4.0% A332 2149 3.4% A321 2752 3.7% A333 1944 3.0% A333 2432 3.2% RJ85 1901 3.0% B77W 2381 3.2% B77W 1574 2.5% B744 2134 2.8% B752 1496 2.3% B752 1899 2.5% B744 1460 2.3% B772 1527 2.0% B772 988 1.5% A319 1449 1.9% B788 926 1.5% B788 1389 1.9% E170 803 1.3% DH8D 690 0.9% E190 765 1.2% B764 661 0.9% A319 756 1.2% RJ85 648 0.9% B764 658 1.0% B77L 628 0.8% DH8D 643 1.0% E190 551 0.7% B77L 516 0.8% E170 529 0.7% Figure 4 Current traffic types by route: (U)L70, (U)L975 (U)Y124 DEXEN-LUTIP P6 REMSI-NELBO 14512 flights in 2016 13377 flights in 2016 AC Type Count Percent AC Type Count Percent A320 5275 36.3% A319 5609 41.9% B738 4924 33.9% A320 2924 21.9% A321 789 5.4% B738 1317 9.8% A319 625 4.3% B733 1148 8.6% B752 573 3.9% B734 425 3.2% B763 542 3.7% F70 291 2.2% B734 464 3.2% E170 262 2.0% Figure 5 Current traffic types by route: (U)Y124, P6 B762 232 1.7% IOM & Antrim Airspace Change Page 9

L10 NW-bound FL255- via KELLY L10 SE-bound FL255- via KELLY 23121 flights in 2016 307 flights in 2016 (see also Figure 7) AC Type Count Percent AC Type Count Percent DH8D 10340 44.7% BN2T 154 50.2% A319 3204 13.9% PA31 32 10.4% AT75 2853 12.3% DA42 19 6.2% SB20 1041 4.5% BE20 10 3.3% A320 848 3.7% A319 7 2.3% ATP 593 2.6% C310 7 2.3% L410 561 2.4% ATP 6 2.0% E170 381 1.6% DH8D 5 1.6% BE20 332 1.4% A332 4 1.3% PA31 327 1.4% C130 4 1.3% B738 260 1.1% F406 4 1.3% A306 258 1.1% A320 3 1.0% B763 3 1.0% PC12 3 1.0% A310 2 0.7% B733 2 0.7% B77W 2 0.7% BE40 2 0.7% C208 2 0.7% C56X 2 0.7% Figure 6 Current traffic types by route: L10 FL255-, split by direction of flight* *Note that this is L10 traffic SE-bound excluding EGNS departures, due to a quirk in the data tool. See below right for EGNS departures via L10 SE-bound. (U)L15 PEPOD-SOSIM EGNS departures via L10 (SE-bound) 30747 flights in 2016 8883 flights in 2016 AC Type Count Percent AC Type Count Percent DH8D 9983 32.5% AT75 2845 32.0% A319 8828 28.7% L410 1614 18.2% A320 4632 15.1% A319 1148 12.9% B738 2072 6.7% SB20 1034 11.6% B733 1301 4.2% C310 348 3.9% E170 515 1.7% ATP 284 3.2% B734 441 1.4% DH8D 278 3.1% E170 130 1.5% BE20 120 1.4% PA31 120 1.4% AT76 99 1.1% AT72 96 1.1% Figure 7 Current traffic types by route: (U)L15, and SE-bound EGNS departures via L10 3.5 Traffic Forecasts The traffic using each route in these sectors (the count columns, para 3.4 above) is forecast to increase as follows: 2016 (source data) to 2018 (first full year of implementation): 2016 + 4.8%* 2016 (source data) to 2023 (implementation +5 years): 2016 + 17.1%* * NATS 2016 Base Case Traffic Forecast. 3.6 Operational Efficiency, Complexity, Delays & Choke Points See para 2.1 for capacity limitation in IOM sector. See para 2.2 for objectives on Monitor Value. See para 3.1 for use of manual tactically-vectored parallel routes in the region. IOM & Antrim Airspace Change Page 10

3.7 Environmental Issues As per the consultation document para 6.2 (Ref 1), we aim to match the proposed route structure to the current vectoring system, thereby reducing controller workload and thus increasing capacity. The lengths of tracks flown by aircraft using the proposed route structure are likely to be comparable to the lengths of tracks flown by aircraft using the original (current) route structure. However they will be doing so in a more systemised way, and the flight plans will be a closer reflection of the actual route of flight. The consultation feedback report (Ref 2) para 4.1 discusses feedback from Dublin-based operators regarding the costs of a small increase in flight plan fuel burn vs the benefits of a reduction in delays. See paragraph 5.3 on page 17 for details of the environmental impacts of the proposal. 3.8 Safety There are no specific safety issues that this proposal is attempting to solve, but we are reducing controller workload to allow for increased capacity. See paragraph 5.6 on page 18 for safety details for this proposal. IOM & Antrim Airspace Change Page 11

4 Proposed Airspace 4.1 Requirements Maintain or improve the level of safety in the affected and neighbouring sectors; Reduce ATC workload (per flight); Increase sector capacity (measured by sector monitor value); Minimise additional controlled airspace required for changes (minimal impact on GA); Have negligible/no impact on military operations. 4.2 What Would Not Change Under the Proposal Existing RNAV5 routes would remain in place, but operators will be encouraged to file the RNAV1 routes via RAD restrictions. 4.3 What Would Change Under the Proposal See maps at Figure 8 and Figure 9 below. This proposal would: introduce four parallel RNAV1 routes over the Irish Sea between Wallasey (WAL) and Dublin; two eastbound and two westbound split by a tactical vectoring area, mimicking the current vectoring practice (see Feedback Report para 5.1); introduce five RNAV1 routes in the current airspace volume between WAL and Belfast (BEL), also mimicking the current vectoring practice (see Feedback Report para 5.1); introduce four RNAV1 link routes to ensure network connectivity is maintained or improved (see Feedback Report para 5.3); extend existing ATS route Y124 and adjust existing ATS route Q4 to improve network connectivity (see Feedback Report para 5.3); make minor amendments at high FLs to the STARs for Manchester, Liverpool, London City, Luton, Stansted and Southend airports, to align with the proposed routes (see Feedback Report para 5.3); simplify the CAS definitions & arrangements in the region (see Feedback Report para 5.2); and require a small strip of additional CAS over the Irish Sea as consulted upon (at least 15nm from any land and none below FL75). IOM & Antrim Airspace Change Page 12

TRA004 New controlled airspace Z196 link added for additional connectivity to NW from the E LISTO Figure 8 Proposed RNAV1 routes with additional CAS strip highlighted NUGRA Y124 extended to LISTO for STAR connectivity IOM & Antrim Airspace Change Page 13

Figure 9 Draft schematic of proposed route usage IOM & Antrim Airspace Change Page 14

Class D EGNS CTR/CTA Class D beneath en-route CAS (no change) Class E TMZ beneath Class C Class E TMZ Class C Figure 10 Proposed CAS arrangements (up to FL195) IOM & Antrim Airspace Change Page 15

4.4 RNAV equipage The equipage rate for aircraft which are RNAV1 capable in the IOM sector is currently 94% 6. RNAV5 aircraft would flight-plan the existing RNAV5 routes and would be monitored by ATC to ensure radar separation is maintained from all other traffic. Restrictions would apply to the retained RNAV5 routes in order to reduce the overall complexity of the network. 4.5 Route allocation The draft flight-plan route allocation is shown on Figure 9 on page 14. This route allocation system would not preclude controllers from vectoring flights, or from giving tactical directs, if they perceive an advantage in flexibility or efficiency. The overall requirement for vectoring would, however, be reduced, so the IOM sector capacity would increase. In accordance with the principle of best-equipped, best-served RNAV1 capable aircraft will be best served by flightplanning the RNAV1 routes. Level restrictions will be in place on the RNAV5 routes, and flight planning systems will default to flight plan RNAV1 aircraft on the RNAV1 routes. There will be no advantage to RNAV1 aircraft filing on RNAV5 routes, and this will be discouraged. See also the Airspace Design Definition (ADD, Ref 11). 6 NATS PBN equipage survey Jan-Feb 2017 based on % airframes using PC IOM sector. IOM & Antrim Airspace Change Page 16

5 Impacts of Airspace Change 5.1 Net Impacts Summary for Proposed Routes Category Impact Evidence Safety/Complexity Capacity/Delay Fuel Efficiency/CO 2 Systemisation of route structure leads to conflict reduction of 53% (IOM sector) and 35% (Antrim sector) Increased MV by 10% Reduce total forecast delay by 100,000+ minutes per year (2023) compared with do-nothing. Reduced likelihood of STAM until 2021/22. System average 3.0kg/flight fuel disbenefit (2018) System average 3.3kg/flight fuel disbenefit (2023) Most affected individual route disbenefit 11kg/flight See Para 5.6 See Para 5.4 See Para 5.3 Noise Leq/SEL No impact See Para 5.2 Tranquillity, visual intrusion (AONBs & National Parks) No impact See Para 5.2 Local Air Quality No impact See Para 5.2 Other Airspace Users Minimal impact See Paras 5.5, 5.8, & 5.9 Table 1: Net Impacts Summary 5.2 Noise, tranquillity, stakeholders on the ground, air quality, biodiversity Under this proposal, all changes to flight-paths would be above FL75 (the majority would be above FL170). The great majority of the affected airspace is over the Irish Sea. The routes cross land at the following points (see Figure 8 on page 13): The northern edge of Anglesey (this route is 2nm south of the existing RNAV5 route, typically aircraft would be FL170 or higher). The south & central Isle of Man (the new routes mimic the current vectoring patterns, typically aircraft would be FL170 or higher). In the mainland area roughly bounded by WAL-AMPIT-NUGRA-LISTO, extended or amended routes are mostly FL150+ except Z197 s lowest useable FL90 within the busy MTMA. Therefore we assess that there would be no noticeable noise or visual intrusion impact to stakeholders on the ground in these areas, no changes to local air quality, and no direct impact on flora, fauna or biodiversity due to the height of the proposed changes. 5.3 CO 2 emissions & fuel burn This proposal aims to systemise the route structure and make it similar to the current vectoring system, reducing controller workload and thus increasing capacity. Systemising the routes would reduce the difference between the flightplanned track and the actual track flown. This has the effect of causing some flightplan routes to slightly increase or decrease in length to more accurately reflect the likely actual track. Consequently, the predictability of fuel uplift for this portion of the route is improved. In response to the consultation, some Dublin-based operators focused on the increase in proposed track lengths. As a result, these Dublin-based operators provided negative feedback on the basis of there being a small increase in flightplan fuel uplift. Users flight planning the proposed route M145 (Dublin jet arrivals) would typically be required to uplift an extra 11kg of fuel per flight. Other routes would benefit, including Dublin jet departures, whilst the reduction in complexity (quantified by calculated reduction in ATC conflicts) decreases greatly (see para 5.6). The Feedback Report para 4.1 (Ref 2) compared predicted costs due to additional fuel uplift with the benefit of reduced delays. See para 5.11 on page 19 for an updated prediction of these costs. Excluding the benefits of reduced delays, overall there would be a fuel disbenefit, summarised as: 2018 increased fuel uplift 519T Ref 10a,c 2023 increased fuel uplift 633T Ref 10a,c Note that flightplan fuel uplift does not necessarily translate into an actual increase in fuel burnt. IOM & Antrim Airspace Change Page 17

5.4 Delays to air traffic The objective of this proposal is to systemise the proposed route structure by mimicking the current vectoring system. This will reduce controller workload and hence reduce the requirement for STAM flow regulations, allowing for the Monitor Value (MV) of the IOM sector to increase by 10%. See also paragraph 2.2 on page 6 and Feedback Report para 4.1 (Ref 2). The delay predictions from the Feedback Report (Ref 2) have been updated. If this proposal was implemented, we predict minimal delays in the region until 2021/22. For this para, the results of delays and costs avoided (compared to the do nothing scenario) summarise as: Year Delay minutes avoided Cost avoided Refs 2018 7,081 290k Ref 10b,c 2023 108,827 5.8m Ref 10b,c Total over 5yrs 2018-23 266,051 13.8m Ref 10b,c 5.5 General Aviation (GA) airspace users The location and altitude of the proposed additional CAS (over the Irish Sea, FL75+ with the majority FL115+) means these proposed changes would have minimal impact on GA/VFR stakeholders. 5.6 Impact on Aviation Safety, including safety analyses and complexity. The main design principle behind this proposal was to reduce manual ATC vectoring (hence complexity), allowing greater capacity for the same controller workload. See para 2.2 for the objectives, para 3.1 for how the current airspace is managed, para 4.3 for how the region would change, and para 6.2 for the design principles of this proposal. Safety plan, information and analysis (Refs 4, 5, 6, 7, 8, 9, 15.) Ensuring the safety of proposed changes is a NATS priority. The proposal has been developed, and will be implemented in accordance with, NATS safety management systems. See the Project Safety Assurance and Human Factors Plan (Ref 7), the Project Safety Hazard Identification and Human Error Safety Assurance Process (Ref 8) and the APSA (Ref 15, supplied pre-implementation). The Route Design Analysis Report RDAR (Ref 9) demonstrates compliance with CAP1385 (Ref 4) and also contains a total design risk calculation. Compliance with CAP1385 (Ref 4) is relevant in the en-route environment. As recommended in CAP1385, assessment has been made of the increased altitude on the nominal navigation performance and the potential impact on route spacing. The assessment was made by the NATS PBN High Level High Speed trial (Ref 5) which specifically investigated the track keeping performance of aircraft at higher altitudes and speeds. The conclusion of this trial was: altitude and speed do not affect conformance to RNAV1 PBN straight leg routes and that the existing theoretical distribution for straight leg deviations is suitable for use in a high-level high-speed environment as well as in low level terminal airspace for a typical UK fleet mix. Hence in accordance with CAP1385 and the additional evidence provided by the HL-HS trial, the proposed route separations have been deemed to exceed the requirements for minimum route separation. The minimum CAS containment required for this proposal is 2.5nm, in order to reduce the volume of airspace required. Typically 3nm is the norm according to the CAA Controlled Airspace Containment Policy (Jan 2014). We have provided evidence that RNAV1 routes are safe using 2nm CAS containment (Ref 6). In due course NATS will propose to the CAA that 2nm becomes the norm for RNAV1 routes, and will request an update to the containment policy (outwith this proposal). Safety representatives from SARG have had oversight of the safety assurance process. Conflict analysis A fast-time simulation was carried out, comparing conflicts generated by the baseline airspace with those generated by the proposed structure, for forecast 2019 traffic levels. IOM & Antrim Airspace Change Page 18

PC IOM s conflicts decreased by 53%, PC Antrim s conflicts decreased by 35%. This is a significant complexity benefit, leading to improved capacity as per the objectives of this proposal. See Ref 10a para 4.2 for details. 5.7 Non-NATS Units Affected by the Proposal The IAA s Shannon and Dublin units were engaged (see para 5.8 below), as was the MoD and BAE Systems Warton (see para 5.9 below). Isle Of Man Ronaldsway Airport was also engaged and had no objection. Airports where STARs would change/truncate at high level were also notified of the proposed change and had no objection (Manchester, Liverpool, London City, Luton, Stansted, Southend). 5.8 IAA - UK-Ireland Functional Airspace Block (FAB) Partners NATS UK-Ireland FAB partners the IAA were identified as a key stakeholder in the proposed changes, as PC IoM sector has a direct interface to both the IAA s Shannon and Dublin units. The IAA has contributed to design workshops and simulations to ensure that the impact of the designs does not detrimentally impact the FAB airspace. During consultation, the IAA stated that some of their Dublin-based customers had raised concerns regarding additional costs this proposal might have on their operation (see para 4.1 of the feedback report Ref 2), and that there could be issues caused by changing the presentation of westbound traffic. Following engagement with the IAA we have mitigated their concerns regarding presentation of traffic. We acknowledge the comments of the IAA s customers as per para 5.3, which led to the IAA s reservations about the impact this proposal could have. We are continuing to work with the IAA on interface agreements using the modified design proposed in this document, mitigating impacts as far as reasonably possible. At the request of the IAA the proposed route structure interfaces with the existing arrival transitions and SIDs at Dublin, hence there are no changes to the COPs at the FIR boundary (see para 6.3.2 re Dublin s proposed new parallel runway and associated implications). 5.9 MoD including BAE Systems The MoD (DAATM) and BAE Systems Warton were identified early on as the stakeholders having the most interest in these changes due to their operations in this area. There was pre-engagement with these stakeholders (see Feedback Report para 2.1 Ref 2). Extract from MoD (DAATM SO3) letter, our ref NTMAC26-1: Having reviewed the stakeholder consultation document, dated June 2016, the MOD has no objections to the implementation of RNAV 1 systemised procedures or the additional airspace proposed to facilitate these routes. Extract from BAE Systems letter, our ref NTMAC03-1: Providing NATS can assure Warton that it can manage Warton s entry into the airspace, and that the Unit has autonomy within it, we do not object to the proposal. Both the MoD and BAE Systems queried the proposed upgraded classification of Y911 to C. That upgrade has been deleted from the final proposal, which would remain Class E TMZ. 5.10 Commercial Air Transport Impact & Consultation Most commercial air transport operators supported or had no objection to the proposal. As per para 5.3 above, some Dublin-based operators fed back concerns that the proposed airspace arrangement would cause increased costs to their operation. This concern was answered in the Feedback Report para 4.1 (Ref 2), which compared the predicted small increases in fuel uplift with the benefit of reduced delays. See next para for more details. 5.11 Economic Impact The Feedback Report para 4.1 (Ref 2) contained a table for forecasts regarding predicted delay avoidance vs potential fuel costs with respect to Dublin operators. This has been updated for the ACP, for 2018 (first full year of operation) and 2023 (five years after implementation). The Benefits Summary report Ref 10c combines and summarises the more detailed evidence in Ref 10a and Ref 10b. IOM & Antrim Airspace Change Page 19

Whilst Dublin arrivals in particular would accrue additional fuel costs per flight of 11kg, this is partly mitigated by other routes in the proposed structure (eastbound), and also greatly outweighed by the benefits of systemisation i.e. reduced complexity/conflicts leading to fewer delays. Over the five years 2018-2023 the predicted net benefit of delay cost avoidance vs additional fuel cost would accumulate to c. 12m. 5.12 Sponsoring Unit Training Requirements See Ref 14 for draft training plan. IOM & Antrim Airspace Change Page 20

6 Analysis of options 6.1 Introduction The NATS model for end-to-end airspace design is characterised by steps, starting with design principles, through design envelopes and finally to specific route alignments. Each step reduces the number of options whilst increasing the detailed understanding of those options that move through to the next stage. The finalised design proposed here is the result of the refinement of the options. 6.2 Design Principles and Envelope discussion CAS volumes in part of the region are being redefined as specified CTAs rather than based on widths of ATS routes (CAA AIC Yellow Y068/2016 refers), and much of the region is being converted from Class A to Class C. CAS containment has been designed to 3nm in general and 2.5nm in specific places. Evidence supplied by NATS Analytics (referenced in paragraph 5.6) shows that 2nm containment would be acceptable under RNAV1 conditions for this proposal. (A parallel review of CAS Containment Policy for RNAV1 routes is ongoing. This piece of evidence will form part of NATS basis for requesting a permanent change to the CAA Containment Policy Statement). The proposed routes have been designed in accordance with the CAA PBN enhanced route spacing guidance in a terminal environment (CAP1385) using a minimum radar separation (MRS) of 3nm. Further supporting evidence supplied by NATS Analytics (referenced in paragraph 5.6 on page 18) shows that the spacings defined in CAP1385 can be expanded to include the en-route high speed high level environment. The design takes into account the constraints of the neighbouring sectors, where flights have an MRS of 5nm. Sector procedures will ensure safe, efficient interactions when transiting between sectors. These have been based on current-day vectoring practices with the proposed aircraft flows being positioned in the same general areas as today. Flight planning rules will ensure that aircraft are flight planned to follow the appropriate route, and each route will keep aircraft separated safely when they are established on the parallel sections. ATC will continue to monitor the traffic flows but intervention will be required much less often. The current RNAV5 routes will need to remain because they provide flight-planning connectivity for non-rnav1- capable aircraft within the region. The overlying Swanwick Sector 7 and the IAA s Shannon sector have 5nm radar separation environments. Hence (for example) traffic climbing from IOM into SWN S7 will transition from MRS 3nm to MRS 5nm. For this reason the proposed eastbound routes, Q36 & Q37, are spaced 5.5nm apart since traffic on these routes will typically climb into the overlying sector. The route spacing has been optimised to take account of the differing radar separation standards, ensuring that transfer to the next sector would always give at least the required 5nm radar separation. Likewise on the proposed westbound routes M144 & M145, aircraft will often be descending from SWN S7 MRS 5nm into the MRS 3nm of IOM. So these routes are separated by 5nm. Flexible Central Tactical Vectoring Area concept The central tactical track allows for the airspace to be systemised for the majority of traffic, but will allow for vectoring flexibility when required. This is the first piece of en-route RNAV1 systemised airspace in the UK, however it is still completely surrounded by non-systemised airspace, and includes a small proportion of traffic which is not yet RNAV1-capable. As the wider network is optimised and systemised over time, the need for tactical vectoring will diminish, however in the near term a degree of tactical intervention will be essential. Aircraft will continue to be monitored by ATC to ensure separation. 6.3 Design Options General 6.3.1 Do nothing (rejected) In the short term, fuel use for Dublin arrivals would not increase as it would under the proposed systemised structure (see para 5.3 on page 17). However, in the longer term delays would build up as para 5.4 on page 18. These delay costs rapidly outweigh the fuel disbenefit over the next five years, hence doing nothing was rejected. IOM & Antrim Airspace Change Page 21

6.3.2 New Coordination points (COPs) at UK/Ireland FIR boundary (rejected) The current route structure links to the coordination points (COPs) BAGSO and LIFFY at the UK/Ireland FIR boundary. New COPs had been considered, as has using current COP BOYNE in a different way, however the IAA has requested that the proposed IOM routes terminate at COPs BAGSO and LIFFY so that the Dublin SIDs & STARs will be unchanged. When the planned Dublin new parallel runway is brought into service, provisionally in 2021, the SIDs & STARs for Dublin will be changed, and at that time it is proposed to introduce more COPs and review the interface with the IOM routes, potentially changing the use of current COP BOYNE. 6.3.3 CAS containment options (3nm and 2.5nm progressed, 2nm rejected) Variations of the minimum CAS containment have been considered. The first is based on the extant minimum CAS containment, i.e. 3nm distance between the outer-most route centre-line and the edge of CAS. This requires a greater overall volume of CAS, however it is in line with extant CAA guidelines. 3nm containment has been used for all new routes except to the NE of P6 in the Antrim sector, where this would require an additional 0.5nm wide strip of CAS to accommodate the proposed M148. In order to avoid adding this 0.5nm fillet, 2.5nm CAS containment is the preferred option in this area. See Design Principles paragraph 6.2 on page 21. 6.3.4 Closer route spacing, to CAP1385 minima (rejected) If the absolute minimum route separations as described in CAP1385 were used between the routes, the routes could be spaced slightly closer together. The reason for choosing 5nm/5.5nm spacing is due to the transitions between MRS 3nm and MRS 5nm as discussed in the Design Principles paragraph 6.2 on page 21. This design option for route separations of significantly less than 5nm was therefore not progressed. 6.3.5 Place RNAV1 route(s) coincident with original RNAV5 routes (partially progressed) One option considered involved overlaying the IOM sector s extant RNAV5 routes (L975 and L70) with RNAV1 routes, and inserting two new RNAV1 routes between them. This would require that the minimum route spacing as per CAP1385 were utilised. This option was not progressed for the reasons in 6.3.4 above. However in the proposed route structure the existing IOM RNAV5 route L70 would be partly overlaid with a new RNAV1 route (M144), and the Antrim RNAV5 route L15 would be partly overlaid with a new RNAV1 route (Q38). It is possible to have coincident route segments (with different designators) using the same waypoints, one RNAV5 and the other RNAV1. Hence whilst we are not seeking to overlay all the RNAV5 routes with RNAV1 routes, there are two instances of this in the proposed design. 6.3.6 Additional airspace south of L975 (rejected) One option considered extending the airspace to the south of L975. This was discounted due to the impact on military operations in the North Wales Military Training Area (NWMTA). 6.3.7 Airspace Classification (Class C favoured over Class A) PC IOM is currently a mix of Class C (at all levels) and Class A (below FL195). PC Antrim is a mix of Class C (above FL195), and Classes E, D and A (below FL195). These CAS volumes are all defined in UK AIP ENR3.1 via ATS routes, airway widths, intersections and complex additional volumes. We propose that, within the region covered by PC IOM and PC Antrim SE of the IOM VOR: ATS-route Class A definitions are changed to Class C in UK AIP ENR3.1; Matching Class C CTAs are established, defined in UK AIP ENR2.1 (incorporating the additional 3nm fillet) so that, in time, CAS defined by ATS routes can be withdrawn leaving the CTAs in place, with ATS route centrelines moving to UK AIP ENR3.3; Matching Class D CTAs are established, unchanged in extents from today for the same reason, except for minor modifications to Strangford CTAs; and The complex confluence of Classes A C, D and E TMZ in the vicinity of BOYNE and IOM VOR would be simplified. Changing the classification of Y911 from Class E TMZ to Class C was consulted upon, considered but discounted (see Feedback Report para 4.57). See Figure 10 on page 15 for overview. See chart Ref 12, selecting appropriate layers. IOM & Antrim Airspace Change Page 22

6.4 Design Options - Direct Route Airspace Currently, when aircraft transition between DRA airspace and lower airspace (using the Belfast TMA) they file direct (DCT) routes to enable a continuous flight planned climb or descent. This flight planning technique works well within the current airspace network. To fully utilise the proposed structure, aircraft need to be flying on the RNAV1 route and not on DCTs even if they are coincidental, as the aircraft could be flying to an unknown navigation standard. This issue has a greater effect on Belfast TMA inbounds as it has the potential to increase either the fuel uplift for aircraft by forcing early descent onto the proposed structure, or to not take full advantage of the systemised route spacing. The following options are possibilities to reduce/negate this: 6.4.1 Replicate the current DCTs (rejected) Replicate the REMSI DCT NELBO with a REMSI DCT LIMKA (M146) and a DCT from REMSI to UVPOK and then ROBOP (M147). It would eliminate the systemisation for the equivalent routes (M146/M147) 6.4.2 Introduce DCTs for the shortest allowable time/distance (rejected) Introduce REMSI DCT NINEB (M146) and REMSI DCT UVPOK (M147). It would create a fuel disbenefit as aircraft would have to plan on being at FL250 by NINEB and UVPOK which is too low, especially for BTMA easterly operations. This would, however, allow the aircraft to use the systemised routes after NINEB/UVPOK and take advantage of the reduced route spacing earlier than in option 1 & 3. 6.4.3 Introduce middle distance DCTs (rejected) Introduce REMSI DCT NINEB DCT IDGAS (M146) and REMSI DCT UVPOK DCT MATUT (M147) Whilst allowing for more efficient flight planning, there is no flexibility for differing rates of descent. If aircraft are at FL250 before IDGAS/MATUT they cannot be treated as being on the systemised routes, which might increase the level of monitoring and therefore the workload of the controllers. This option is better than the previous two, but not ideal. 6.4.4 Install routes into DRA airspace for a limited area (progressed) For BTMA arrivals, M147 and M148 s upper limit would be FL460 within a limited area in the DRA, and RAD restricted to limit their use. Aircraft would fly the routes but tactically separated above FL255. As soon as they descend through FL255, systemised separation can be applied. BTMA arrivals must be FL250 by IDGAS/MATUT this is a reasonable expectation for BTMA arrivals. For BTMA departures, Q38 and Q39 s upper limit would be FL460 within a limited area in the DRA, and also RAD restricted. This would allow BTMA departures to have continuous flight planned climb at a flexible rate using the systemised routes until passing FL255 when tactical separation would be applied. Route M146 would climb traffic into the DRA or would continue below, without the need for special arrangements. Route Z198 would only be used for traffic below the DRA linking to M148. This option provides a good balance between allowing flexible descent/climb profiles out of/into the DRA, and using the underlying systemised routes for a sustained period of time, reducing controller workload. 6.4.5 Introduce RNAV1 STARs into the Belfast TMA (not progressed, potential future development) BTMA arrivals could transit from the upper air routes at the entry point to the DRA, and join RNAV1 STARs for the appropriate airfield. This is the most flexible method for BTMA arrivals and would not involve level restrictions being imposed on inbounds, replicating the descent profile of today s operation. This is not a solution for BTMA departures either RNAV1 SIDs or other RNAV1 solution would be required simultaneously. This is a potential future solution. 6.4.6 DRA Summary The solution we are progressing is detailed in para 6.4.4. Whilst we believe a good solution for inbounds would be the introduction of RNAV1 STARs, a future project may be tasked with making Belfast TMA changes and the introduction of RNAV1 STARs would be under that project s remit. The STAR method also does not address the systemisation of BTMA departures, requiring a solution to be implemented at the same time. IOM & Antrim Airspace Change Page 23

This would allow routes into the DRA for a limited area, RAD restricted to ensure they are only used for Belfast TMA arrivals/departures. Aircraft could flight plan for continuous descent (in most scenarios) as well as enabling controllers to take advantage of route systemisation once aircraft have entered PC Antrim s airspace (below FL255 NW of REMSI). It has the added benefit that controllers can take advantage of route systemisation for BTMA departures until they pass FL255. The other DRA options provide less satisfactory solutions, and hence were not progressed: 6.4.1 is the most flexible for descent profile but doesn t allow for route systemisation; 6.4.2 is the least flexible and most restrictive but uses route systemisation; and 6.4.3 sits between the others without adequately allowing for the differences in descent profile between BTMA easterly and westerly operations. IOM & Antrim Airspace Change Page 24

7 Airspace Description Requirement CAP 725 Appendix A Paragraph A5 provides a list of requirements for a proposed airspace description. These are listed below: CAA CAP725, Appendix A paragraph 5 Description for this Proposal Requirement. The proposal should provide a full description of the proposed change including the following: a The type of route or structure; e.g. Airway, UAR, Conditional Route, Advisory Route, See para 4.3 CTR, SIDs/STARs, Holding Patterns, etc; b The hours of operation of the airspace and any seasonal variations; As per current hours/conditions of operation c Interaction with domestic and international en-route structures, TMAs or CTAs with an explanation of how connectivity is to be achieved. See para 4.5 and ADD Ref 11. Connectivity to aerodromes not connected to CAS should be covered; d Airspace buffer requirements (if any); N/A e Supporting information on traffic data including statistics and forecasts for the various categories of aircraft movements (Passenger, Freight, Test and Training, Aero Club, Other) and Terminal Passenger numbers; See paras 3.4 and 3.5 f Analysis of the impact of the traffic mix on complexity and workload of operations; RNAV1 vs RNAV5 traffic would be split, and airframes that are RNAV1-equipped exceed 94% in the IOM sector. g h i j k Evidence of relevant draft Letters of Agreement, including any arising out of consultation and/or Airspace Management requirements; Evidence that the Airspace Design is compliant with ICAO Standards and Recommended Practices (SARPs) and any other UK Policy or filed differences, and UK policy on the Flexible Use of Airspace (or evidence of mitigation where it is not); The proposed airspace classification with justification for that classification; Demonstration of commitment to provide airspace users equitable access to the airspace as per the classification and where necessary indicate resources to be applied or a commitment to provide them in-line with forecast traffic growth. 'Management by exclusion' would not be acceptable; Details of and justification for any delegation of ATS. See section 12 Appendix A: List of LoAs to update (LoAs will be updated pre-implementation, presuming approval) CAP1385 applied, with supporting evidence, also CAS containment evidence See para 5.6 and Refs 4, 5, 6, 9. Majority changed from Class A to Class C. See Figure 10, design principles para 6.2 and chart Ref 12. The classification of the airspace volumes would be honoured as per AIP ENR 1.4 No change to delegation of ATS to the IAA at the western FIR boundary adjacent to Dublin. IOM & Antrim Airspace Change Page 25

8 Supporting Infrastructure & Resources CAA CAP725 Appendix A Paragraph A6 provides a list of requirements for supporting infrastructure/resources. These are listed below: a b c d e f g CAA CAP725, Appendix A Paragraph 6, general Requirements Evidence to support RNAV and conventional navigation as appropriate with details of planned availability and contingency procedures. Evidence to support primary and secondary surveillance radar (SSR) with details of planned availability and contingency procedures. Evidence of communications infrastructure including R/T coverage, with availability and contingency procedures. The effects of failure of equipment, procedures and/or personnel with respect to the overall management of the airspace must be considered. The Proposal must provide effective responses to the failure modes that will enable the functions associated with airspace to be carried out including details of navigation aid coverage, unit personnel levels, separation standards and the design of the airspace in respect of existing international standards or guidance material. A clear statement on SSR code assignment requirements is also required. Evidence of sufficient numbers of suitably qualified staff required to provide air traffic services following the implementation of a change. Evidence of Compliance/Proposed Mitigation See Report on RNAV1 coverage (Ref 16) No change, demonstrably adequate for purpose No change, demonstrably adequate for purpose Failure modes will be analysed and appropriate contingency procedures established as per NATS safety management Failure modes will be analysed and appropriate contingency procedures established as per NATS safety management No change to SSR code allocation. Suitably trained staff will be in place before implementation (see draft training plan Ref 14). IOM & Antrim Airspace Change Page 26