Foreword Cardiff Airport connects Wales to the world, handling over a million passengers a year with 50 direct routes available and more than 900 connecting destinations worldwide through hubs including Amsterdam Schiphol, Dublin and Barcelona. In March 2013, Cardiff Airport was bought by the Welsh Government and a strategy has been implemented which addressed every aspect of the business including a number of improvements to enhance the customer experience. This consultation is part of our commitment to keep the local community informed of advances in technology which could impact on how aircraft navigate at Cardiff and other airports across the World. Area Navigation (RNAV) is at the heart of new technology with the potential to streamline air traffic procedures, ultimately delivering fuel savings, reduced emissions and an improved noise environment for people on the ground. While its full utilisation may be some years in the future we believe that RNAV, which uses satellitebased navigation systems to ensure more reliable, repeatable and predictable flight paths, is worth investing in today. This document provides further details on the case for doing so, and explains the procedures involved. Thank you for taking an interest in Cardiff Airport, we are committed to listening to all responses as part of this consultation. Debra Barber, Managing Director
Section 1 Introduction This document describes the Cardiff Airport proposal to replicate, implement and eventually replace the current final approach routes into Cardiff Airport with more accurately defined routes utilising the improved capabilities of modern aircraft. Section 2 explains what Area Navigation (RNAV) is, how it will be used, and its potential benefits. It also clarifies the scope of the consultation. Section 3 explains why this consultation is required and lists the stakeholders with whom we are consulting. Section 4 provides an overview of current operations at Cardiff Airport including diagrams illustrating the tracks taken by aircraft approaching the airfield. Section 5 sets out the proposed RNAV routes, which are designed to replicate the current tracks as closely as possible. Section 6 sets out environmental considerations. Section 7 sets out how stakeholders should respond to the consultation and explains what will happen next.
2. Introduction of RNAV at Cardiff Airport This consultation concerns modernisation of the existing arrival routes to Cardiff Airport. The existing routes used by aircraft (termed conventional routes) rely on 1950s technology of ground based radio beacons. A well established and much more accurate form of navigation is area NAVigation (RNAV) which uses a combination of satellite and ground-based navigation technology to permit aircraft to follow a precisely defined path over the ground with far greater accuracy than is possible with conventional routes. This in turn enables pilots to fly pre-determined, predictable arrival profiles. Aircraft today already use RNAV extensively to fly in our airspace, even though the existing conventional routes have not been specifically designed for its use. Processes are underway at a European level to make modernisation of the route system a legal requirement for the UK and other European states by 2020. This will require all member states, including the UK, to upgrade routes to the RNAV standards. This legislation will be enacted by UK mandates to be introduced by the Civil Aviation Authority (CAA). The CAA is planning to mandate that all operators will have to be RNAV 1 approved by November 2017, and then require RNAV routes to be introduced by winter 2019. Modernising our conventional routes is therefore mandatory and inevitable; this consultation concerns how we intend to achieve this at Cardiff Airport with minimal impact to our stakeholders. Cardiff Airport and its airline customers have identified an opportunity to introduce RNAV for the final stages of the approach phase to the airport. The Cardiff Airport airspace was thoroughly reviewed, redesigned and updated to suit the current and anticipated future levels of traffic growth in 2006. This process considered the requirements of other airspace users. Our proposals for the introduction of RNAV are based on updating the later stages of approach routes through replication whereby the existing route alignment is preserved as much as possible, whilst catering for the greater navigational accuracy of Performance Based Navigation (PBN). The use of RNAV across the UK will enhance navigational accuracy and should introduce a number of key benefits. These include: a safer and more efficient Air Traffic Control (ATC) system requiring less controller intervention; more efficient operations leading to reduced cost, flying time and emissions; the ability to allow more predictable patterns of over flight as well as stabilised arrivals and approaches which should generate less noise. By giving pilots a defined flight path from beginning to end they can plan a descent which avoids level segments, optimises power settings and speed in the descent, configures the aircraft for minimum noise, reduces fuel burn and keeps the aircraft higher over the ground for longer. Such operations are known as Continuous Descent Operations involving unbroken descent from cruising altitude to the runway. The introduction of RNAV replications of the current procedures will enable more effective and reliable use of Continuous Descent Operations. An aircraft must be certificated as having the appropriate navigation systems and flight crew training before it can fly RNAV1 procedures. The operation of the Air Traffic Management system beyond Cardiff will also affect the likely take-up of RNAV procedures in the immediate future. ATC at Cardiff will still need to interact with arriving aircraft on a flight by flight, tactical basis, creating a spread of aircraft tracks, similar to that experienced now. This is not predicted to change significantly in the short term, until new arrival management tools are implemented on a pan-european basis. However, over time, the new routes will become the primary inbound tracks flown by the majority of aircraft.
The Civil Aviation Authority (CAA), with support from the Department for Transport (DFT), the Ministry of Defence (MOD), NATS (the UK s leading Air Navigation Service provider) and the Irish Aviation Authority (IAA), has been leading work to develop the Future Airspace Strategy (FAS) for the period to 2030. The CAA s primary objective is to develop a safe, efficient airspace that has the capacity to meet reasonable demand, balances the needs of all users and mitigates the impact of aviation on the environment. This national strategy is aligned with the UK s commitments under the Single European Sky (SES) legislation, including implementation of the Single European Sky Air Traffic Management Research (SESAR) programme. The aim of this proposed change is to build on these UK and European initiatives, utilising the latest navigation technology to enable modern aircraft to achieve the benefits mentioned above. The proposal does not influence or change the number of aircraft able to use the airport and traffic numbers are not expected to increase as a consequence of the change. Note: throughout this document altitude or heights of aircraft are expressed as height above mean sea level unless indicated otherwise.
3. Consultation The purpose of this consultation is to obtain feedback from stakeholders who may be affected by or have an interest in this proposal. Cardiff Airport has spoken with the CAA on the consultation process and they have agreed that provided this airspace change proposal replicates the existing patterns of aircraft arriving at Cardiff Airport today and does not introduce any additional residents to aircraft noise or introduce new volumes of traffic, it is appropriate for the consultation process to include: - The Cardiff Airport Consultative Committee which includes representatives of the local community and other organisations that have expressed an interest in the activities of the Airport; - Local authorities in the neighbourhood of the airport or whose area of responsibility is overflown by the routes which are to be affected but who are not already represented on the Cardiff Airport Consultative Committee; - Bristol City Council - The Ministry of Defence; - The airlines operating at Cardiff Airport; and - Principal airspace users and stakeholders as represented on the National Air Traffic Management Advisory Committee (NATMAC). The consultation follows the procedures set out in CAP 725 and the Cabinet Office Code of Practice on Consultation. This consultation document has been prepared by Cardiff International Airport Limited with assistance from NATS. The consultation period begins on 15th December 2014 and will run until 20 th March 2015. Details of how to respond and the next steps can be found in Section 7.
4. Overview of current operations at Cardiff Airport The Cardiff Airport runway is aligned south-east / north-west. The north westerly runway is designated as runway 30 as aircraft landing on or taking off from the runway will be facing a magnetic compass heading of 300 whilst the south easterly runway is designated runway 12. Aircraft generally land and take-off into the wind which means that Runway 30 is the predominant runway direction, being used by around 60% of aircraft movements 1. In 2013 approximately 14860 Instrument Flight Rules (IFR) aircraft arrived at Cardiff Airport. IFR represents the majority of larger commercial aircraft operating at Cardiff. Of these, 39% (5795 aircraft) landed on runway 12, and 61% (9065 aircraft) landed on runway 30. The distribution of arrivals by time of day is shown in Figure 1. This covers two months (January and August 2013) and should be seen as indicative of the winter and summer schedules for Cardiff Airport. Figure 1: Arrivals by Month and Time of Day 1 Based on total runway movements at Cardiff Airport for the calendar year 2013.
Runway 12 The routes taken by aircraft approaching runway 12 in July 2013 are shown in Figure 2, which uses a flight path density plot to indicate aircraft tracks (the highest concentrations of aircraft are indicated by the darker red colour). The heights of descending inbound aircraft along the densest arrival track are shown indicatively on Figure 3. These routes are positioned to avoid densely populated areas where possible, with aircraft from the north routing just to the east of Bridgend and those from the south approaching over water and making land fall in a sparsely populated area. Figure 2: Density Plot of Current Runway 12 Arrival Tracks
Figure 3: Indicative Descent Heights for Current Runway 12 Arrivals
Runway 30 A similar plot of routes taken for aircraft approaching runway 30 during July 2013 is shown in Figure 4. These routes are over the Severn estuary and away from populated areas. The heights of the descending inbound aircraft along the densest arrival track are shown indicatively in Figure 5. The arrival routes from both the North and South are predominantly over water, with the route from the north passing to the east of Flat Holm island and passing over Steep Holm island. Figure 4: Density Plot of Current Runway 30 Arrival Tracks
Figure 5: Indicative Descent Heights for Current Runway 30 Arrivals
Missed Approach Procedures A missed approach is a procedure followed by a pilot when an approach to an airport cannot be completed to a landing and is often referred to as going around. The instructions for the missed approach may be assigned by ATC prior to the clearance for the approach. If ATC has not issued specific instructions prior to the approach and a go around is executed, the pilot must follow the (default) missed approach procedure specified for that runway.. Instrument approaches are designed with a specified missed approach procedure which includes a height to climb to, a magnetic heading to fly and then a route to follow. At Cardiff the formal missed approach procedures are designed so that an aircraft will climb straight ahead on the runway heading to an altitude of 3000 feet and then turn to the north and continue in a loop back to the airport. Once overhead the airport the aircraft will enter the airport holding pattern and await further instructions from Air Traffic Control. Illustrations of these procedures for both runways are given in Figure 6 and Figure 7. It should be noted that these tracks are not fixed and are illustrative only, as the turn for each procedure is initiated at 3000ft and this will occur at a different point for each aircraft depending upon how quickly it climbs and reaches that altitude. The default missed approach procedure is used vary rarely at Cardiff as a result of interaction between the aircraft which is going around and other aircraft operating near to the airport. This means that Air Traffic Controllers issue individual headings and heights to separate the aircraft carrying out the missed approach from the other aircraft before positioning them for another second approach. As a consequence of this ATC intervention, aircraft tracks for missed approaches over the ground rarely follow the same route. As an indicator of how infrequently aircraft go around at Cardiff airport, in 2013 there were a total of 33 missed approaches by IFR aircraft. This equates to 0.2% of the total IFR movements.
Figure 6: Conventional Missed Approach Runway 12 Figure 7: Conventional Missed Approach Runway 30
5. Proposed RNAV Routes The proposed RNAV approaches have been designed to replicate the current aircraft tracks as closely as possible in order to reduce additional impact to local residents. The proposed approaches are shown in broad context in Figure 8 and then overlaid on the existing aircraft tracks in Figure 9. These approaches are defined by a series of waypoints; those identified as the Initial Approach Fix (IAF) and the Intermediate Fix (IF) being fly-by points and the Final Approach Fix (FAF) being fly-over points. Aircraft will fly directly overhead a fly-over point but will generally turn inside a fly-by way point, using it as a reference about which to make a turn. Figure 8: Proposed RNAV Routes
Final Approach Fix Initial Approach Fix Final Approach Fix Initial Approach Figure 9: Proposed RNAV Routes Overlaid on Existing Aircraft Tracks Initial Approach Fix Runway 12 RNAV Approach The Proposed RNAV route for runway 12 is shown in more detail in Figure 10. The route has been designed to take the tracks to the east of Bridgend and west of Pencoed to the North, and to remain over water as much as possible to the south. This route represents no change to the areas of concentrated traffic over the routes flown today. Initial Approach Fix The descent profile for aircraft following this route is indicated in Figure 11 and is designed to match the current aircraft s altitude as closely as possible, within the constraints imposed by complying with RNAV procedures. It is expected therefore that noise profiles, (which are already low for approaching aircraft) should differ very little from today.
2400 ft Figure 10: Runway 12 RNAV Track 2400 ft 2400 ft Top of Descent Point Cardiff Airport
2400 ft Figure 11: Runway 12 RNAV Descent Profile Runway 12 RNAV Missed Approach The proposed runway 12 missed approach design is shown in Figure 12 with the missed approach climb profile shown at Figure 13. 2400 ft 2400 ft Top of Descent Point
Figure 12: Runway 12 RNAV Missed Approach Cardiff Airport
Cardiff Airport 3000ft Top of Climb 3000ft Figure 13: Runway 12 RNAV Missed Approach with Climb Indicators It is expected that the RNAV missed approach for runway 12 will be utilised less than the conventional missed approach (which itself is rarely used) as not all aircraft are RNAV equipped. The uptake will increase over time as the number of RNAV equipped aircraft increases, however the total number of aircraft executing a missed approach is not expected to rise as a consequence of this proposal. Runway 30 RNAV Approach Runway 30 is shown in more detail in Figure 14. The route has been designed to follow the centre of the densest area of concentration of traffic to ensure that the current tracks over the ground are replicated as closely as possible. The approach from the North and South are both over water until the very late stages of approach. The descent profile for aircraft following this route is indicated in Figure 15 and is designed to introduce as little change from the current aircrafts altitude as possible, within the constraints imposed by complying with RNAV procedures. It is expected therefore that noise profiles (already low for approaching aircraft) will differ very little from today. The RNAV approach has been designed to route between the islands of Steep Holm and Flat Holm thus avoiding overflying, as much as possible, this wildlife sanctuary.
1600 ft 1600 f Figure 14: Runway 30 RNAV Track Cardiff Airport Top of Descent Point Flat Holme 1600 ft Steep H
1600 ft Figure 15: Runway 30 RNAV Descent Profile Top of Descent Point 1600 ft Runway 30 RNAV Missed Approach The runway 30 RNAV missed Approach design is shown in Figure 16 with the missed approach climb profile shown at Figure 17. Cardiff Airport
Figure 16: Runway 30 RNAV Missed Approach Cardiff Airport
Top of Climb 3000ft 3000ft Cardiff Airport Figure 17: Runway 30 RNAV Missed Approach with Climb Indicators It is expected that the RNAV missed approach for runway 30 will be utilised less than the conventional missed approach (which is rarely used) as not all aircraft are RNAV equipped. The uptake will increase over time as the number of RNAV equipped aircraft increases, however the total number of aircraft executing a missed approach is not expected to rise as a consequence of this proposal. Likely use of RNAV Routes The majority of the larger aircraft (twin engine commercial jets and above) operating at Cardiff Airport are equipped with the technology and crew training to make use of the proposed RNAV routes. There is also a drive from industry, the airspace regulator and the Government to increase the use of RNAV. Both the UK FAS and SESAR projects are encouraging the widespread introduction of RNAV based navigation across the UK and Europe for partial implementation in the period to 2020. However, uncertainty around the exact arrival times of traffic means that Cardiff ATC will still need to intervene tactically in the routing of individual flights in order to achieve a safe, orderly and expeditious flow of traffic. The result is likely to be a spread of inbound tracks, in line with those of today. As the proportion of aircraft suitably equipped for RNAV increases, the opportunity will be taken to move increasing numbers of aircraft onto the RNAV routes. This should deliver the safety, resilience, noise, and emissions benefits referred to earlier, in increasing quantities.
6. Environmental Considerations This proposal is to replicate existing conventional routes with RNAV alternatives in line with upcoming European Legislative requirements. In accordance with the CAA policy for RNAV replication, Cardiff Airport is not required to undertake assessment of local air quality or CO 2 emissions (Ref 7). This is because the effect associated with these potential impacts is expected to be small as a consequence of the objective to replicate rather than change the existing routes. The previous sections provide pictorial comparisons of today s flight paths and the expected location of flight paths as a consequence of the replications. Accurate Track Keeping Aircraft using RNAV are often said to be on rails in the sky, i.e. they can follow a defined route accurately and repeatedly. This proposal is based upon the principal that the proposed RNAV routes will be designed to follow current aircraft tracks as closely as possible. This will avoid additional noise for areas not already subject to aircraft noise. The use of RNAV technology enabling aircraft to fly routes more accurately does mean that over time as an increasing number of aircraft use the RNAV routes there will be an increased concentration of aircraft over certain core tracks, replacing the spread that is seen today. The use of RNAV technology will allow an improvement of the positioning of aircraft to minimise track variation currently seen today. This increased track conformity, is in line with DFT guidance on environmental objectives. (Aviation Policy Framework, Section 3.31 (Ref 5)) which embodies the Government guidance that it is desirable to concentrate aircraft along the fewest possible number of specified routes in the vicinity of airports. Typically locations either side of the routes will be overflown less and will be exposed to less aircraft noise, while locations close to the route centreline will be overflown more, and hence will be exposed to more aircraft noise. Improved Descent Planning When flying RNAV approaches, pilots have more certainty regarding the distance left to run before reaching key points in the approach. This enables them to plan their descent such that they are able to stay higher longer and to execute smooth continuous descents. This can save fuel, reduce CO 2 emissions, and reduce noise impact. However these benefits are small and not easily quantified. The proposed change is not justified on the basis of these benefits and hence no analysis is required (see Ref. 7). Noise Due to the nature of replication there is no requirement to undertake noise modelling for this proposal. This is in line with the Future Airspace Strategy and CAA Policy requirements for replication (Refs. 6 & 7). The governments overall policy on aviation nose, as established in the Aviation Policy Framework, is to limit, and where possible, reduce, the number of people in the UK significantly affected by aircraft noise. Consistent with this policy, the Government believes that in most circumstances, it is desirable to concentrate aircraft along the fewest possible number of specified routes in the vicinity of airports and that these routes should avoid densely populated areas as far as possible. The latest available noise contours for Cardiff Airport (2007) are shown in Figure 18 whilst the outer extremities of the 57dB LAeq contours 2, along the runway centreline, are shown over laid on the current aircraft tracks in Figure 19. Aircraft using the RNAV approaches are following straight line portions which are identical to the conventional procedure tracks (aligned with the extended centreline of the runways). Hence there will be no change to the noise contours as a result of the 2 LAeq 16 hours is the preferred method to measure the aggregated exposure to repeated noise events throughout the day. The resulting value takes into account the total sound energy over the period of time interest. In this case 16 hours from 7AM to 11PM.
introduction of RNAV replications. For this reason new contours have not been produced for this consultation. Figure 18: 2007 Noise Contours
57dB LAeq 16hr Markers Figure 19: Traffic Density Plots with 57dBLA Markers Air Quality Management Area (AQMA) There is no AQMA established at Cardiff Airport and as this proposal will lead to largely unchanged traffic patterns and aircraft behaviour it is assumed that there will be no adverse impact upon Local Air Quality as a result of this proposal.
7. How to respond to this consultation Consultation on the proposals detailed in this document will run from 15 th December 2014 until 27 th March 2015 following which all responses will be considered before a formal submission is made to the CAA. The approach taken to consultation is outlined in Section 3, and the stakeholders listed are requested to respond whether or not they have an objection to the proposal. A full list of consultees is provided in Appendix A. Email is the preferred response mechanism, although postal responses will be accepted and processed in the same way. All responses should be titled RNAV Consultation and should state clearly in the first line on whose behalf the response is being made. Responses must also state whether or not the respondent agrees to personal details being passed to the CAA, by amending the following text as appropriate: I/We agree/do not agree that personal details contained within this response may be sent to the CAA as part of the Airspace Change Proposal. Responses should also include one of the three statements below: I/We support the proposal for implementation of RNAV replications of approach routes at Cardiff Airport. I/We object to the proposal for implementation of RNAV replications of approach routes at Cardiff Airport. I/We have no objection to the proposal for implementation of RNAV replications of approach routes at Cardiff Airport. Subsequent text should then substantiate the reasons for support or objection. Please include contact details for use in the event of any queries relating to your response. The CAA requires all consultation material to be included in any formal submission. If you do not want your name and address details to be passed to the CAA, please ensure you opt out using the wording provided above. Apart from providing details to the CAA, Cardiff Airport undertakes that personal details or content of responses and submission will not be disclosed to any third parties without prior permission. This document can be viewed online in English http://www.cardiff-airport.com/cardiff-airport-rnav-consultation-document/ Or in Welsh http://www.maesawyr-caerdydd.com/dogfen-ymgynghori-maes-awyr-caerdydd-rnav/ Email responses should be sent to: consultation@cwl.aero Postal responses should be sent to: RNAV consultation Head of Airfield Ops Cardiff Airport
CF62 3BD A report summarising responses to this consultation will be published on the Cardiff Airport web site shortly after the closing date. Respondents will be sent a link to a copy of this report using the contact details provided. Taking all responses into consideration, Cardiff Airport will then submit a formal proposal for the implementation of RNAV approach replications including full details of all consultation responses and any related correspondence. The CAA will then review the proposal (which can take up to 17 weeks) and reach a regulatory decision. If the proposal is approved, the implementation process could take a further 12 weeks. This consultation is being conducted by Cardiff Airport but is overseen by the CAA s Safety and Airspace Regulation Group (SARG) to ensure compliance with the process set out in CAP 725 (see section 3). If you have any comments on the way in which this consultation is being conducted, please contact: Head of Business Management Safety & Airspace Regulation Group CAA House 45-49 Kingsway London WC2B 6TE Please note that this address should only be used for concerns relating to non-adherence to the consultation process. Correspondence on details of the consultation should be addressed to Cardiff Airport.
Referenced documents List of documents referenced in this publication: (1) CAP 725, CAA Guidance On The Application Of The Airspace Change Process, March 2007, CAA Directorate of Airspace Policy http://www.caa.co.uk/docs/33/cap725.pdf (2) CAP 724, CAA Airspace Charter which defines the authorities, responsibilities and principles by which the CAA Director of Airspace policy conducts the planning or airspace and related arrangements in the UK. http://www.caa.co.uk/docs/33/cap724.pdf (3) Cabinet Office Code of Practice on Consultation https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/255180/consultation- Principles-Oct-2013.pdf (4) Guidance to the Civil Aviation Authority on Environmental Objectives Relating to the Exercise of its Air Navigation Functions https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/269527/air-navigationguidance.pdf (5) HM Government Aviation Policy Framework, 2013 https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/2739/draft-aviationpolicy-framework.pdf (6) Civil Aviation Authority, Future Airspace Strategy for the United Kingdom 2011 to 2030 www.caa.co.uk/fas (7) Civil Aviation Authority, Policy Statement, Guidance On PBN SID Replication For Conventional SID Replacement, August 2013. (8) Policy for the Application of Performance Based Navigation in UK/Irish Airspace 2011 http://www.caa.co.uk/docs
Appendix A Cardiff Airport Consultative Committee Bridgend County Council Cardiff Airport Cardiff Council Llancarfan Community Council Regal Travel ABTA & Advantage Vale of Glamorgan Council Local Authorities Bristol City Council Rhondda Cynon Taff County Council MOD MOD ST Athan DAATM Cardiff Airlines British Airways CityJet KLM Links Air Thomson Thomas Cook RyanAir Vueling Other Airlines / Operators Aeros EasyJet FlyBe Virgin NATMAC Aviation Environment Federation (AEF) Airport Operators Association (AOA) Aircraft Owners & Pilots Association (AOPA UK) British Airways (BA) British Aerospace Systems (BAE Systems) British Airline Pilots Association (BALPA) British Air Transport Association (BATA) British Balloon & Airship Club (BBAC) British Business & General Aviation Assc (BBGA) British Gliding Association (BGA) British Hang Gliding & Paragliding Assc (BHPA) British Microlight Aircraft Association (BMAA) British Model Flying Association (BMFA) British Parachute Association (BPA) British Helicopter Association (BHA) Civil Aviation Authority (CAA) General Aviation Safety Council (GASCo) Guild of Air Traffic Control Officers (GATCO) Helicopter Club of Great Britain (HCGB) Heathrow Airport Ltd Heavy Airlines Light Aircraft Association (LAA) Light Airlines Low Fares Airlines (LFA) Ministry of Defence (MoD) National Air Traffic Services (NATS) PPL/IR (Private Pilots Licence/Instrument Rating) Unmanned Aerial Vehicles Assc (UAVA) UK Flight Safety Committee (UKFSC)
Appendix B A APF AQMA ATC C CAA CACC CAP CDO CO 2 D DFT F FAF FAS I IAA IF IAF IFR M MOD N NATMAC P PBN R RNAV S SARG SES SESAR T TOD U UK Aviation Policy Framework Air Quality Management Area Air Traffic Control Civil Aviation Authority Cardiff Airport Consultative Committee Civil Aviation Publication Continuous Descent Operations Carbon Dioxide Department for Transport Final Approach Fix Future Airspace Strategy Irish Aviation Authority Intermediate Fix Initial Approach Fix Instrument Flight Rules Ministry of Defence National Air Traffic Management Advisory Committee Performance Based Navigation Area Navigation Safety and Regulation Group Single European Skies Single European Skies Air Traffic Research Top of Descent United Kingdom