© 2019 nats (en-route) plc nats unclassified l4162- page ......l4162- page revised ats route...

© 2019 NATS (En-route) plc NATS Unclassified L4162- Revised ATS Route Structure over the Irish Sea | Post-Implementation Review of 21

Publication history Issue Month/Year Change Requests in this issue

Issue 1.0 Feb 2019 First issue released to SARG.

Issue 1.1 Feb 2020 Additional information/clarifications included following CAA guidance

Contents 1. Introduction ........................................................................................................................................................................ 4 2. Background ........................................................................................................................................................................ 4 3. Key Objectives ................................................................................................................................................................... 6 4. Air Traffic Management Requirements ........................................................................................................................ 7 5. Military Air Traffic Management Requirements ......................................................................................................... 8 6. Areas of Contention .......................................................................................................................................................... 8 7. Environmental Conclusions ............................................................................................................................................ 8 8. Effectiveness of Change................................................................................................................................................ 10 9. Other Benefits .................................................................................................................................................................. 11 10. Operational impact .................................................................................................................................................... 11 11. Airspace Change Process Issues and Recommendations for Requirements .............................................. 11 12. PIR Safety Analysis ................................................................................................................................................... 11 13. Operational Analysis of the Airspace Development ............................................................................................ 14 14. Operational Analysis of Overall Environmental Impact ...................................................................................... 15 15. Conclusions ................................................................................................................................................................ 15 16. Appendix A Feedback Received .............................................................................................................................. 16 17. Appendix B Additional Information ........................................................................................................................ 18


1. Introduction 1.1 The CAA approved the implementation of a revised ATS route structure over the Irish Sea, in the Isle of

Man (IoM) and Antrim sectors which was implemented on the 9th of November 2017.

1.2 This document forms part of the document set required in accordance with the requirements of Stage 7 of the CAP725 airspace change process (Post Implementation Review).

1.3 The stakeholders affected by this airspace change were engaged to provide comment on its first year in operation.

2. Background 2.1 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 Ireland.

2.2 The previous network as shown in Figure 1, was operating at capacity in the IOM sector. This proposal was to provide additional capacity in the IOM sector, reducing the likelihood of delays in the region. It was also to modernise this part of the network to take advantage of improved navigation capabilities available on modern aircraft. The basis of the design was to systemise the tactical vectoring used by controllers as shown in Figure 2.

Figure 1 Pre Change Routes


Figure 2 Pre Change Vectoring

2.3 Capacity limitations in the IOM sector often resulted in the application of short-term ATC measures (STAMs). A typical example was where Dublin declared dual runway operations, which enabled them to expedite first rotation departures. The majority of these departures route through IOM sector in the climb to cruising levels. This situation quickly lead to the IOM sector reaching maximum capacity, which then resulted in STAMs being required at Dublin.


Figure 4 Post Change Routes

4. Air Traffic Management Requirements 4.1 Safety

4.2 Safety must be maintained or improved in the area; however there were no immediate safety concerns.

4.3 Capacity

4.4 The primary objective of this airspace change was to increase the capacity of the IOM sector by systemising the route network using PBN routes. The increase in capacity will, in turn, minimise delays, which given forecast growth otherwise would have been significant.

4.5 Efficiencies

4.6 The introduction of systemised PBN routes will increase efficiency of the airspace. The design is also future-proofed to allow integration of flows to support Dublin’s second parallel runway operation with minimal modification.

4.7 Training

4.8 The introduction of the systemisation in this ACP required training for all ATCOs valid on IOM and Antrim sectors, with Supplementary Instruction given to ATSAs.


5. Military Air Traffic Management Requirements 5.1 From the consultation with the military, the MOD had no objections to the proposal, whilst BAE

Systems said that ‘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.’

6. Areas of Contention 6.1 The airlines were focused on the impacts on fuel uplift and changes in track mileage.

6.2 Some Dublin based operators expressed concern that the new routes would increase fuel uplift/burn. This was addressed as part of the consultation documentation, where the long term cost of delay, if no change took place, was shown to vastly outweigh the cost of the extra fuel.

6.3 As a result of the delays in the IOM sector, the area was listed as an OPA (Operational Partnership Agreement) Hotspot. Since the implementation of the change, quarterly updates have been given to the OPA. These detailed environmental data (including track mileage flown and change in fuel burn). It also showed that where possible, subject to controller workload, the majority of Dublin arrivals are vectored direct to BAGSO rather than remaining on the longer M145 route. This reduced the average track mileage flown on these flights.

6.4 The final of these updates was delivered at the Airspace and Flight Efficiency Partnership meeting where the airlines endorsed the report without objection and agreed the (hotspot) project could be closed. This agreement that the Hotspot was no longer required is evidence that the airlines are content that the changes have achieved their objectives.

6.5 See also Paragraph 16.4 below, which gives feedback from the NATS Airline Customer Account Manager, for further detail.

6.6 There was a consideration raised in the feedback from stakeholders about the filing of RNAV5 flight-plans by aircraft RNAV1 capable, in order to obtain theoretically more cost efficient routes. This is addressed in Section 13.4.

6.7 Table 1 details the dialogue that has continued to take place since ACP implementation. The final report output was presented at the November 2018 FEP (Flight Efficiency Partnership) meeting. There were no objections and the matter was closed. This is also shown in Appendix B.

Table 1 Engagement between NATS and Dublin based airlines since ACP implementation Meeting Date FEP 15/11/2017 FEP 21/03/2018 AFEP 14/11/2018 AFEP 06/03/2019

7. Environmental Conclusions 7.1 A small fuel and CO2 disbenefit was required in order to improve the capacity in the region as seen in

Table 2 and 3. These figures were based on RNAV1 flights only pre-implementation (since without RNAV1 equipage, the flights cannot use the post implementation routes, and hence are ineligible for comparison). This included 91% of all of the flights in the region for the preceding year. The flights were then categorised against the equivalent post implementation route for the comparison. Only aircraft types found in both samples were included to avoid bias from newer, more efficient, aircraft.


No aircraft use these routes at these levels and these portions are over the high seas (LIFFY 20nm from Irish coast, RULAV 18nm from Angelsey coast. Additional information is shown in Appendix B.

8. Effectiveness of Change 8.1 Capacity Increases

8.2 The target capacity improvement of the change has been achieved, with an increase in Monitor Value of the IoM Sector from 43 to 48 (5 additional aircraft movements per hour). This is an increase of 11.6%, which is higher than the 10% forecast in the ACP. This is equivalent to one extra aircraft per hour more than was predicted in the ACP.

8.3 The Antrim Sector is not capacity constrained and maintained a Monitor Value of 38.

8.4 The C22 delay in the area since the implementation of the airspace change has been reduced to 55 minutes. This was from a single regulation applied on the 17th November, which was within two weeks of deployment. This is a reduction from 476 minutes of C2 delay in the preceding year and no further C2 delay has happened in the region since.

8.5 General Unit Comments on the Effectiveness of the Change

8.6 Operations Manager Dublin, IAA: The PLAS IoM implementation has been fairly seamless to Dublin ACC from an Air Traffic Management (ATM) perspective and minimal disadvantage to its ATM operation has been experienced. Moreover, because of the additional flexibility afforded by the extra routes inside UK airspace, there have been associated opportunities to enhance standing agreements between Dublin ACC and Prestwick Centre to enable reductions in separation and agreed longitudinal spacing. In consequence, this has allowed Dublin departure traffic to be flowed more quickly from Dublin Airport into its en-route phase of flight. The IAA ANSP has already seen significant Air Traffic Management benefit from the PLAS initiative, which is also expected to enable elements of future proofing for airspace arrangements post 2021 to be realised.

8.7 Lakes Sector ATCO: The delivery of outbound traffic from Dublin, by PC IOM sector to Swanwick sector 7, is presented in a much more timely & consistent manner which is of significant benefit to airspace users and controllers. Verbal coordination is generally reduced in relation to outbound traffic which results in an overall reduction in coordination.

Tactical benefits are realised by Swanwick controllers and airspace users in the majority of cases. Earlier transfer of traffic facilitates continuous climb operations with a corresponding fuel benefit.

8.8 Manager ATC Airspace Design Prestwick Centre:

8.9 IOM: There is a reduced controller workload and hence RT which provides more thinking time and has assisted in raising capacity. Aircraft transferred from Dublin/Shannon is less controller intensive and can operate on own navigation.

8.10 Antrim: A small improvement relative to the previous design, use of new points beneficial for departures into the sector (Belfast), however, BTMA arrivals still require headings due to their use of 5nm separation criteria.

2 C2 delay is delay which is attributable to capacity limitations.


9. Other Benefits 9.1 There are no other benefits identified.

10. Operational impact 10.1 Feedback from all affected stakeholders:

10.2 Air Navigation Service Providers

10.3 See Section 8.

10.4 Commercial

10.5 Throughout the implementation period of this change, regular updates were given to the Airline stakeholders through the OPA meetings, where the change in the area was endorsed.

10.6 See Section 6 and Appendix A.

10.7 Military

10.8 Since the implementation of this change, the comments from DAATM state that they have liaised with the MOD Stakeholders who agreed that they were no noticeable impacts to MOD operations as a result of this change.

10.9 Warton ATC stated that post implementation they have found that their operations have been able to continue unhindered, although it is important to recognise that the increase in the number of routes combined with their closer alignment requires, at times, a greater interaction with NATS controllers to accommodate certain test profiles. To date that has not proven to be problematic and they acknowledge the good working relationship with the sector controllers concerned.

10.10 General Aviation

10.11 This ACP occurred over the Irish Sea and at altitudes equal to or above FL75, therefore the GA community were not an affected stakeholder due to the nature of the change and as such have not been asked for feedback. Additional information is shown in Appendix B.

11. Airspace Change Process Issues and Recommendations for Requirements 11.1 None.

12. PIR Safety Analysis 12.1 Analysis of Mandatory Occurrence Reports (MORs) in the IOM and Antrim sectors for the year before

and after implementation showed a decrease in MORs of 9% in the IOM and 36% in Antrim sector. (see Table 3).

Table 4 MORs in the year before & after implementation - IOM/Antrim Sectors

09/11/2016 - 08/11/2017

09/11/2017 - 08/11/2018

% increase

Antrim 11 7 -36% Isle of Man 22 20 -9% Control sectors† 221 206 -7%

12.2 The breakdown in MORs are listed in Tables 4 to 7 for the Antrim and IOM sectors. These are also shown in Appendix B.


Table 5 Breakdown of MORs in the Antrim sector

ANT Incident Family 09/11/2016 - 08/11/2017 09/11/2017 - 08/11/2018

Accident 1 1 External 0 0

Loss of Separation 1 0 Occurrence 9 6

Overload 0 0

ANT Incident Type 09/11/2016 - 08/11/2017 09/11/2017 - 08/11/2018

Aircraft Accident 1 1 Avoiding Action 1 0

Infringement 1 1 Laser Event 1 0 Level Bust 1 1

Loss of Separation 1 0 Mayday 0 0 Military 1 0

Overload 0 0 PAN Medical 4 2

PAN Technical 1 0 Premature Transfer 0 0

Route Deviation 0 0 RT Failure 0 0 TCAS RA 0 2 TCAS TA 0 0

12.3 For Pre-implementation ANT the granular breakdown gives a total of 12 events not 11 as one event was classified as both an infringement and a military incident

Table 6 Breakdown of MORs in the IOM sector

CC-IOM Incident Family 09/11/2016 - 08/11/2017 09/11/2017 - 08/11/2018 Accident 0 0 External 0 3 Loss of Separation 0 0 Occurrence 19 16 Overload 3 1


CC-IOM Incident Type 09/11/2016 - 08/11/2017 09/11/2017 - 08/11/2018

Aircraft Accident 0 0 Avoiding Action 1 1

Infringement 0 1 Laser Event 1 1 Level Bust 5 3

Loss of Separation 0 0 Mayday 2 0 Military 1 0

Overload 3 1 PAN Medical 5 2

PAN Technical 1 0 Premature Transfer 0 1


12.4 For Pre-implementation CC-IOM the granular breakdown gives a total of 22 events not 21 as one event was classified as both a TCAS RA and a military event

12.5 When the number of movements is factored in, the percentage decreases in rates of MORs (per 100,000 movements) were 14% in the IOM and 36% in Antrim sector (see Table 4 below).

Table 7 MORs Rates (per 100,000 movements) and % Change in MOR Rates

09/11/2016 - 08/11/2017

09/11/2017 - 08/11/2018

% increase

Antrim 9.2 5.9 -36% Isle of Man 13.2 11.4 -14% Control sectors† 18.2 17.5 -4%

† Prestwick Lower control sectors used: Talla, Galloway, West Coast, Tay, Wallasey, S29, North, East, Stafa and Trent.

12.6 The number of MORs has fallen in the year since the changes were introduced.

12.7 Any variation seen in the incidents counts or percentage differences cannot be seen as statistically significant due to the small number of incidents analysed.


13. Operational Analysis of the Airspace Development 13.1 Delay analysis

13.2 Predicted delay avoided in 2018 due to the implementation was 7,081 minutes per year with a cost benefit of £290k. Forecasting out to 2023 was delay avoided of 108,827 minutes per year with a cost benefit of £5.8m.

13.3 Whilst these numbers were based on zero delay in 2018, the single 55 minute delay, two weeks after implementation would not have affected the overall benefit numbers.

13.4 RNAV Equipage

13.5 There was a concern that aircraft may file as RNAV5, whilst having RNAV1 equipage, since the RNAV5 routes are slightly shorter.

13.6 Table 5 contains the percentages of flights filing each route type. This shows the RNAV1 equipage filing has increased significantly, and that aircraft are not filing as RNAV5 in order to get a shorter flight-planned route.

Table 8 RNAV Equipage Rates in IOM/Antrim sectors RNAV1 RNAV5 Pre Implementation 91% 9% Post Implementation 98% 2%

13.7 For feedback on the operational aspects of the change see also Section 8.

13.8 Figure 5 shows the systemised route in operation over a one week period. It can be seen that there is still a level of tactical vectoring taking place for Dublin arrivals whilst the traffic levels are at their current state, but there is now the capacity to deal with a much higher number of aircraft in the future.


16. Appendix A Feedback Received 16.1 This section contains the feedback in full received from ATC units and airlines on the airspace change

approximately one year after it went live.

16.2 Operations Manager Dublin, IAA With regard to the PLAS IoM Project, the IAA ANSP was consulted comprehensively on the airspace changes associated with the requirement to introduce RNAV-1 routes to enhance sector capacity by adding extra flows, all without diminishing safety. The PLAS IoM implementation has been fairly seamless to Dublin ACC from an Air Traffic Management (ATM) perspective and minimal disadvantage to its ATM operation has been experienced. Moreover, because of the additional flexibility afforded by the extra routes inside UK airspace, there have been associated opportunities to enhance standing agreements between Dublin ACC and Prestwick Centre to enable reductions in separation and agreed longitudinal spacing. In consequence, this has allowed Dublin departure traffic to be flowed more quickly from Dublin Airport into its en-route phase of flight. In addition, because of the substantial co-ordination with the PLAS Project, the construction of the new Parallel Runway at Dublin (for introduction into service in 2021), as well as attendant increases in air traffic demand with extra outbound and inbound routes, have all been considered in order to assist the further development of an appropriate and efficient interface between Dublin ATC and Prestwick Centre. In conclusion, therefore, the IAA ANSP has already seen significant Air Traffic Management benefit from the PLAS initiative, which is also expected to enable elements of future proofing for airspace arrangements post 2021 to be realised.

16.3 Lakes Sector ATCO The PLAS changes have predominantly brought benefits to the LKS sector operation. There is still some complexity experienced in relation to dealing with Dublin arrivals. However this relates more to the interaction experienced with Belfast TMA departures which was an existing issue. This can result in increases in verbal coordination between Swanwick Sector 7 and PC IOM sector to resolve. However the delivery of outbound traffic from Dublin, by PC IOM sector to Swanwick sector 7, is presented in a much more timely & consistent manner which is of significant benefit to airspace users and controllers. Verbal coordination is generally reduced in relation to outbound traffic which results in an overall reduction in coordination. In summary, tactical benefits are realised by Swanwick controllers and airspace users in the majority of cases. This manifests itself in the form of earlier transfer of traffic facilitating continuous climb operations with resultant fuel burn benefit.

16.4 NATS Airline Customer Account Manager Regarding feedback on the change, I think the best post-implementation evidence is provided through the OPA Hotspot that ran all through the PIR period, ie from implementation in November 2017 to 3rd November 2018. My summary of the Hotspot is below: Some airlines expressed a concern that the IOM/Antrim airspace change would deliver future capacity in the longer term but cause unacceptable additional fuel burn for Dublin arrival traffic in the short term due to having to fly longer systemised routes. NATS had stated before implementation that the longer routes would only be used when the airspace was capacity constrained and controllers were too busy to provide tactical vectoring – when workload permitted, controllers would facilitate tactical direct routeing whenever possible. Due to these concerns it was agreed with airlines that NATS would establish a


project to report on the performance of the airspace during the first year following implementation on 9th November 2017. NATS collated data on environmental results and provided this to airlines on a quarterly basis – a final report was then presented to airlines at the Airspace & Flight Efficiency Partnership meeting on 14th November 2018. In addition to environmental data, NATS also provided radar plot data to show the actual tracks that aircraft had been flying – this showed that more than 75% of Dublin arrival traffic had been provided with direct routeing and that the new systemised routes were only used when the additional capacity was required. The airlines endorsed the report without objection and agreed that the project could be closed.

16.5 Manager ATC Airspace Design Prestwick Centre

16.6 IOM Virtually all positive feedback: Reduced controller workload and hence RT which provides more thinking time and has assisted in raising capacity (a number of similar comments received) Aircraft transferred from Dublin/Shannon is less controller intensive and can operate on own navigation Coupled with the introduction of 3nm most revolutionary airspace change yet introduced! Possible improvements for the interface arrangements with the adjoining WAL and S7 have been suggested, and will be investigated for future implementation

16.7 Antrim Less headings /less RT Not much difference to previous airspace structure Belfast Aldergrove aircraft positioning has improved Use of 3nm separation within the sector has assisted but still some interface issues with transferring aircraft to Rathlin sector Old school - still use headings but the additional waypoints make it easier to send aircraft direct ( More of a UCE issue I think) A small improvement relative to the previous design, use of new points beneficial for departures into the sector (Belfast), however, BTMA arrivals still require headings due to their use of 5nm separation criteria.

16.8 DAATM

I have liaised with the MOD Stakeholders, specifically the DAATM Airspace Strategy Supervising Officer via email in January 2019 and they agreed that there were no noticeable

impacts to MOD operations as a result of this change.

16.9 BAE Warton BAE Systems recognises the importance of airspace modernisation, particularly when set against the growth, both actual and forecast, in GAT. Post implementation we have found that our operations have been able to continue unhindered, although it is important to recognise that the increase in the number of routes combined with their closer alignment requires, at times, a greater interaction with NATS controllers to accommodate certain test profiles. To date that has not proven to be problematic and we acknowledge the good working relationship we have with the sector controllers concerned.


We were pleased with the level of consultation undertaken by NATS prior to this change where we agreed that the planned changes would not impact adversely on our operations; however, we did not support the last minute change to the ACP proposing reclassification of airway Y911 from Class E+TMZ to Class C. NATS Response: This reclassification was withdrawn from the IOM/Antrim ACP as it fell under the CAAs Post Implementation Review of the Class F ADR Change.

17. Appendix B Additional Information 17.1 Item Requirement

1

Para 36 of CAP1584 details the conditions attached to the approval of the airspace change specifically that NATS Customer Affairs continue to maintain constructive dialogue with the Dublin based airlines that have raised concerns over the additional westbound flight-plan mileage,

Please provide evidence of this dialogue. Following the introduction the IOM was considered an OPA hotspot and quarterly reports were produced and sent to airlines . Chris Dare presented the final report output at the Nov18 FEP. The slide pack is attached, slides 53-69 detail the IOM hotspot results. There were no objections and the matter was considered closed. EIN/RYR attended each of the following meetings:

Meeting Date FEP 15/11/2017 FEP 21/03/2018 AFEP 14/11/2018 AFEP 06/03/2019

2

Para 3.1 The objective of this proposal was to increase the monitor value for the IOM sector from 43 to 47 to allow the region to operate with fewer flow restrictions being applied and hence less delay.

Please provide evidence of this increase. The Sector Monitor Value grid lists the MVs currently as 48. The spreadsheet gives the MV as 48. Flow bulletins provided also document the increase.

3 Para 3.2 Maintain or improve the level of safety in the affected and neighbouring sectors;

Please provide further evidence of this, please can you describe the types of events incurred before and after implementation, as I would like to understand the context of the MORs before and after implementation. Further detail provided below

ANT

Incident Family 09/11/2016 - 08/11/2017

09/11/2017 - 08/11/2018

Accident 1 1 External 0 0 Loss of Separation 1 0 Occurrence 9 6 Overload 0 0

CC-IOM

Incident Family 09/11/2016 - 08/11/2017

09/11/2017 - 08/11/2018

Accident 0 0 External 0 3


Loss of Separation 0 0 Occurrence 19 16 Overload 3 1

ANT

Incident Type 09/11/2016 - 08/11/2017

09/11/2017 - 08/11/2018

Aircraft Accident 1 1 Avoiding Action 1 0 Infringement 1 1 Laser Event 1 0 Level Bust 1 1 Loss of Separation 1 0 Mayday 0 0 Military 1 0 Overload 0 0 PAN Medical 4 2 PAN Technical 1 0 Premature Transfer 0 0 Route Deviation 0 0 RT Failure 0 0 TCAS RA 0 2 TCAS TA 0 0

Note: For Pre-implementation ANT the granular breakdown gives a total of 12 events not 11 as one event was classified as both an infringement and a military incident.

CC-IOM

Incident Type 09/11/2016 - 08/11/2017

09/11/2017 - 08/11/2018

Aircraft Accident 0 0 Avoiding Action 1 1 Infringement 0 1 Laser Event 1 1 Level Bust 5 3 Loss of Separation 0 0 Mayday 2 0 Military 1 0 Overload 3 1 PAN Medical 5 2 PAN Technical 1 0 Premature Transfer 0 1



Note: For Pre-implementation CC-IOM the granular breakdown gives a total of 22 events not 21 as one event was classified as both a TCAS RA and a military incident.

4 Para 3.3 Reduce ATC Workload (per flight)

Can you provide evidence of how this has been measured and the outcome. Excerpt from the HESAP5 report below: Isle of Man:

• The IoM changes have led to a reduction of workload and they free up thinking capacity (as long as ATCOs actually use and trust the systemised tracks: “It was commonly reported by the IoM ATCOs that the systemisation has been beneficial from their perspective. Almost all of the interviewed ATCOs found that the systemised tracks freed up thinking capacity. The interviewed ATCOs also stated that when the new tracks were introduced, there was some reluctance amongst them to use them due to low initial trust in the systemisation, however with time and exposure to using the new tracks, controllers’ confidence and trust in the systemisation has increased. One controller also highlighted that they understood that opting not to use the systemisation and the new tracks could make situations more difficult and could lead to them becoming overwhelmed. Two ATCOs added that the systemised routes are not helpful and create additional workload in situations where aircraft do not follow the routes due to flight planning issues.” “When asked about the benefits of this deployment, IoM controllers commented that they were using the routes as much as possible when it was busy which had lowered their workload, increased efficiency and thinking capacity. It was also noted that having the waypoints displayed on their radar screens was felt to be more useful than displaying the routes. Overall, controllers raised that they used fewer headings than before the changes were introduced and they were comfortable with working more traffic.”

• However there was a slight increase in complexity in certain areas: “Interviewed controllers also noted areas of additional complexity and potential confusion which were introduced with these airspace changes. Two IoM ATCOs commented that whilst they generally perceive the changes to be good for the sector, as it frees a lot of thinking capacity, the area around SOSIM has to be closely monitored has changed due to the crossing-over points of routes; the conflict point around SOSIM has to be closely monitored - it has changed due to the introduced changes. Additionally, controllers noted that occasionally there are RNAV5 aircraft that fly high-level (the majority fly at a lower level than RNAV1 aircraft), which can cause some confusion. Other than this the changes were found to have resulted in improvements.”

5 Para 3.5 minimise additional controlled airspace required for

The statement in 10.11 contradicts this objective, can you confirm there has been no impact on GA and please provide evidence to support your conclusion.


changes (minimal impact on GA) There was only a very small strip of additional CAS created as part of this ACP over the Irish Sea (at least 15nm from any land and none below FL75). This adheres to objective 3.5.

6 Para 3.6 Have negligible/no impact on military operations.

Para 16.8 does constitute sufficient evidence to support the PIR, there is no information to indicate who liaised with the MOD when or what was discussed, please provide evidence to support this statement. DAATM were asked for feedback. I corresponded by email with (DAATM-Airspace Strategy SO2) in Jan 2019, who stated “I have liaised with the MOD Stakeholders and they agreed that they were no noticeable impacts to MOD operations as a result of this change.” Email attached.

7 Para 7.6 proposal assumed no noticeable noise or visual intrusion impact

Please provide evidence to demonstrate that there were no aircraft below 7000ft, what was the minimum height of aircraft on this route in the last 12 months compared with the terrain. Aircraft do fly below 7000ft in this region mostly flying to/from the Isle of Man itself. Of the routes introduced only the following had sections with base levels below 7000ft:

Q36 between RULAV-LIFFY (base FL45), Q37 between BAKOX-LIFFY (base FL45).

However in fact no aircraft use theses routes at these levels and these portions are over the high seas, not over land (LIFFY is 20nm from the Irish Coast) RULAV is 18nm from the Angelsey coast. I have attached a radar trajectory plot showing aircraft below 7000ft. The minimum height on the over-land portions of any of the routes is greater than 7000ft.

8 Para 13.1 delay analysis Please provide information of your forecasted delay vs actual delay and the methodology used to determine those figures. See report attached.

9 Figure 5 plot density What period does this cover? Figure 5 (post change) covers the period 12-18 Nov 2018

10 Para 7.2 CO2 disbenefit

Please clarify the methodology used for prediction and that for calculating the actual. please also provide an explanation as to why there is such a difference between the predicted and the actual. We have provided a document that details the methodology used for CO2 emissions calcs (and the difference between enabled and actual).

11

There is no explanation of 3Di anywhere in the document or whether a positive or negative result means a disbenefit or improvement

Please either explain the measure the methodology for how it is calculated and its applicability, or remove it. This link gives a detailed description of 3Di. To clarify 3Di is a measure of 3 dimensional Inefficiency. A higher score is worse (more inefficient) hence a reduction in 3Di score is an improvement/ benefit.

12

Para 15.1 This PIR has provided evidence that predictions made in the ACP to justify the changes have been met or exceeded.

At this stage, I am not able to draw the same conclusion without additional evidence being provided. Questions answered above.

End of document

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