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1 EGOA FINAL REPORT

2 Air Navigation Services Division REPORT D-LFV (73) - This page is intentionally left blank

3 Air Navigation Services Division REPORT D-LFV (73) EXECUTIVE SUMMARY This is the final report from the LFV project Enhanced General aviation Operations by ADS-B (EGOA). The EGOA project started January 2003 and ended December Background Aviation traffic is constantly expanding. This implies higher demands on the pilots as they are called on to use more technology more frequently. Meanwhile, airspace above dense population areas will be harder to gain access to by the general aviation sector because the commercial aviation sector will lay claim to more of that airspace. The current radar based surveillance system and communication based on voice radio will not be sufficient to meet future needs as air traffic increases. Maintaining a high level of safety also requires improvements of the technical systems both onboard aircraft and on the ground. A system that initially will work as a complement to and eventually could replace current radar system is ADS-B (Automatic Dependent Surveillance Broadcast). FIS-B (Flight Information Service Broadcast) is a service that can supply aircraft with weather information and/or other aeronautical information. The expectation of EGOA, that can be seen as an ADS-B and FIS-B preimplementation project, has been to investigate possibilities for general aviation and to maintain access to controlled airspace and to get better service and information for the general aviation sector. A trigger for the start of the EGOA project has been the many safety occurrence reports that involve general aviation aircraft. This report includes a summary of the Air Navigation Services Safety Occurrence Reports (ANS-DA) for the time January 2003-June The summary addresses two types of Safety Occurrences; Flight in controlled airspace without clearance from ATC Runway incursion The summary indicates that general aviation aircraft are overrepresented in the reports concerning flight in controlled airspace without clearance from ATC. One conclusion of this report has been that the technique and applications addressed in the EGOA project can lower the number of incidents. Objectives The project objectives are summarised in the bullets below: To evaluate and validate ADS-B and FIS-B for general aviation pilots. To evaluate and validate ADS-B in a mixed radar and ADS-B environment from a controller perspective.

4 Air Navigation Services Division REPORT D-LFV (73) To show potential benefits with ADS-B for Search and Rescue. To spread knowledge about the about the issues addressed in the project and the proposed solutions to a wider audience within the aviation community. To provide experiences and input to standardisation efforts for ADS-B and FIS-B To provide knowledge, experiences and an infrastructure, ground as well as airborne, to be used by future research and implementations projects addressing ADS-B, FIS-B or other data link applications. Method More than twenty general aviation aircraft have been equipped with VDL mode 4 transceivers with ADS-B and FIS-B capability, many of the aircraft have also been equipped with a cockpit display of traffic information (CDTI). The Air Traffic Control at the four major airports in Östgöta TMA has had air situational displays with ADS-B functionality installed. All equipment has been for evaluation purposes only and not for operational decision making. Throughout the project the experiences from participating pilots and air traffic controllers have been collected and used in the validation of the addressed applications. Both interviews and forms have been used to gather input. Operational and Environment Description The EGOA project has been performed in Östgöta TMA, which is located in the southeastern part of Sweden. Inside the TMA there are four controlled airports; Stockholm/Skavsta, Norrköping/Kungsängen, Linköping/SAAB and Linköping/Malmen. A control tower is located on each airport. A terminal control (Östgöta Control Centre) is located in Norrköping at Kungsängen airport. The terminal control has approach control to all airports in Östgöta TMA. A number of smaller, uncontrolled, airfields are also located within the TMA. Project Related Safety Work The EGOA project has performed flight trials under normal operational conditions. To identify possible hazards with respect to flight safety a functional hazard assessment have been carried out. No equipment has been placed in the vicinity of an operational position to eliminate the risk for an air traffic controller to accidentally use the ADS-B information for separation purposes in a stressed situation. Each participating aircraft owner also has had to sign a contract stating that no decision making in the cockpit must be based on information from ADS-B or FIS-B, the equipment was to be used for evaluation purposes only.

5 Air Navigation Services Division REPORT D-LFV (73) Equipment All aircraft or vehicles participating in the project have been equipped with a VDL Mode 4 transceiver. Two different kind of transceivers have been used, one VDL-Mode-4-only transceiver and one radio combining 8,33 MHz Voice and VDL Mode 4. In many of the aircraft participating in the project a Cockpit Display of Traffic Information (CDTI) has been used, based on a Personal Digital Assistant (PDA). The ground infrastructure has been consisting of four VDL Mode 4 ground stations at the major airports in the TMA and servers for ADS-B and FIS-B services. The Askersund SSR have been providing radar coverage. Demonstrations and Workshops As part of the dissemination of the EGOA results, and in order to support the exchange of information with ANS organisations and the general aviation community, a series of EGOA demonstrations and/or workshops have been conducted. The first workshop was dedicated to ADS-B out. This event, which included live demonstrations, was held in Linköping, Sweden, in early September The second demonstration was held in Östgöta TMA in early April 2005 and presented live on-line at the annual EUROCONTROL Briefing for Business and General Aviation in Brussels. The third EGOA workshop was a joint event with the EUROCONTROL CASCADE programme and took place in late October The EGOA work on both ADS-B and FIS-B was presented. The target audience common for all workshops has been the European general aviation community and persons responsible for short-term as well as long-term development in ANS organisations and airports. Business case A business case has been developed for a multi-mode radio (MMR) combining VHF Voice and VHF Data Link capability. The purpose of the business case has been to show whether or not the multi-mode radio can generate enough benefits for the general aviation aircraft owner to motivate the investment of such a radio. Many issues could be solved through the equipage of an additional flight aid that enables pilots to readily access information in the cockpit. The study identified the need for a set of capability levels to be offered to the general aviation/aerial work (GA/AW) market. These ranged from the basic MMR (with an ADS-B out functionality only) to the high-end integrated CDTI solution. Some conclusions drawn from this assessment have been that GA/AW users that utilise the full functionality of the MMR should expect to gain considerable benefits. The situation for very small aircraft (gliders, microlights etc) is more

6 Air Navigation Services Division REPORT D-LFV (73) complex. Equipping with the basic MMR solution would enable the user to mitigate any disbenefits arising from regulatory restrictions on sections of airspace, as well as benefiting from the added safety of being visible to ATC. The situation for these very small aircraft can be summarised as a straight cost tradeoff between the MMR and the individual pieces of equipment likely to be required in the future (e.g. Mode S transponder, GNSS and 8.33 khz radio). Conclusions Most of the project objectives mentioned above can be considered to be fully achieved whilst others can be considered partly achieved and requiring further work. The common view of the pilots has been that being allowed to use the ADS-B application operationally will definitely enhance both safety and situational awareness. The risk for navigation mistakes will be lower if the pilot is allowed to use the moving map feature of the CDTI and the risk for incursion in the air or on the runway will decrease significantly when having other aircraft and airport vehicles displayed on the CDTI. An opinion received from almost all of the pilots has been that the current solution with a PDA as the hardware platform is not good enough for cockpit use. Conclusion is that the CDTI must be based on another hardware platform, more suitable for the cockpit environment. Regarding the ADS-B transceiver it has fulfilled the requirements for user friendliness, operating autonomously and not requiring the pilot to attend the system. The capability of providing many functions in one piece of equipment such as communication, surveillance and navigation has also been considered valuable if allowed to be used operationally. The pilots who have used the multi mode radio type, housing both VHF voice radio and data link capability, have considered this especially valid. The air traffic controllers at the participating ATC units have been generally positive to the ADS-B application. The average air traffic controller is however not very interested in the technique behind the plot. The main issue for the air traffic controller is to make the aircraft visible on the air situational display in a safe and reliable way. However the mix of aircraft with SSR only, ADS-B only and SSR+ADS-B capability has raised a number of HMI issues that requires more work. The feedback from the air traffic controller regarding their first impression on ADS-B can be summarised as conservatively positive. It has also been the opinion that the introduction of ADS-B in an area as Östgöta TMA does not imply a significant difference for the air traffic controller compared to the current way of working. The EGOA project has verified that en-route coverage as well as low level and airport surface coverage can be achieved over a large area with ADS-B at a significantly lower infrastructure cost than with conventional SSR and surface movement radars (SMR). The use of ADS-B in search and rescue operations (SAR), as information source for last known position of missing aircraft but also

7 Air Navigation Services Division REPORT D-LFV (73) for fleet management of SAR aircraft, has during the EGOA project created great interest at the Swedish Air Rescue Coordination Centre. Two FIS-B applications were addressed in the project, MET REPORT and Temporary Segregated Areas. From the air traffic controller s point of view the MET REPORT application as designed in EGOA would probably lead to a reduction of the workload. More in-flight evaluation of the MET REPORT application as well as the TSA application is needed to confirm the expectations on these applications. Recommendations for further work It is recommended that further investigations be made concerning the use of ADS-B in search and rescue operations. It is recommended that the impact on the air traffic controller of usage of ADS-B and FIS-B in general aviation aircraft is investigated further, possibly by simulations. It is recommended that the development of new controller air situational display units continues and is coordinated with other ADS-B projects. The same is also valid for the airborne side regarding cockpit displays (CDTI). It is recommended that further investigations are made concerning ADS-B in military aircraft. An introduction of ADS-B in military aircraft will most likely have a positive affect on the air traffic controller s work. The situational awareness will probably get affected in a positive way and it would most likely lead to reduce of workload. It is recommended that further investigations be made concerning ADS-B in Unmanned Aerial Vehicles (UAV). It is recommended that the development of FIS-B services and on the standardisation thereof continues. The FIS-B services have been received with great interest. The business case also indicates that such services can be the driver for aircraft owners to invest in equipment that also gives benefits to the ANSP in terms of wide spread ADS-B equipage. It is recommended that a cost-benefit analysis for large-scale VDL mode 4 equipage of the Swedish general aviation aircraft fleet should be developed by LFV.

8 Air Navigation Services Division REPORT D-LFV (73) Document history Rev Date Author(s) Page(s) Information November 2006 Roger Li Released document

9 Air Navigation Services Division REPORT D-LFV (73) EGOA FINAL REPORT References [1] Preliminär Rapport Funktionell Riskkälleanalys, PFHAR, v , , Anne-Lovise Linge, LFV [2] Business case for the use of VHF-VDL multi-mode radio within General Aviation/Aerial Work, v. 2.0, , Gordon, Hanson and Stanley, Helios Technology, P248_11D008 [3] Utvärdering av CDTI i EGOA-projektet en riskidentifiering på mikro- och makronivå, , Per Christofferson et al, Linköping University

10 Air Navigation Services Division REPORT D-LFV (73) CONTENTS 1 INTRODUCTION Background EGOA Project Objectives Scope of document EGOA project group Abbreviations OPERATIONAL AND ENVIRONMENT DESCRIPTION Environment Airspace Airports Air Traffic Services PROJECT RELATED SAFETY WORK Preliminary Functional Hazard Assessment TECHNICAL ARCHITECTURE Aircraft and vehicles Ground CONTROLLER ISSUES Problem description Methods Verification and Validation PILOT AND AIRCRAFT OWNER ISSUES Problem description Method Verification and Validation GROUND INFRASTRUCTURE ISSUES Problem description Method Verification and Validation DEMONSTRATIONS AND WORKSHOPS First EGOA Demo and Workshop...57

11 Air Navigation Services Division REPORT D-LFV (73) 8.2 Second EGOA Demo Third and Final EGOA Demo and Workshop BUSINESS CASE FOR COMBINED VOICE & VDL MODE 4 RADIO Business case executive summary CONCLUSIONS Achievement of project objectives Application specific conclusions Recommendations for further work...66 APPENDIX A...68 APPENDIX B...71

12 Air Navigation Services Division REPORT D-LFV (73) 1 INTRODUCTION This document contains the final report from the LFV project Enhanced General aviation Operations by ADS-B (EGOA). The EGOA project has been running from January 2003 to December The document is divided into ten major sections: This section, Introduction, contains the background of EGOA, project objectives, presentation of project group members and their roles etc. The second section, Operational and Environment Description, contains information about the operational conditions in the TMA where EGOA has been active as well as the environmental conditions such as topography, weather etc. Section number three describes the safety work performed within the EGOA project to provide evidence that the EGOA project would be no infringement in the safety of normal day-to-day operations. The forth section contains a technical description of the equipment used in the project and the technical architecture. The three following section describes what has been done in the EGOA project from three different point of views, the controller s, the pilot s/aircraft owner s and the ground infrastructure responsible (at the air navigation service provider or at the airport). Each section contains a description of the problems the EGOA project are addressing that each group are facing, what have been done within EGOA to solve these problems and what the outcome of these efforts is. Section number 8 is an account of each of the three EGOA demonstrations and workshops that have been arranged to spread knowledge about the ongoing activities. Section number 9 contains a summary of a Business Case for the type of combined Voice and Data Link radio that has been used in the EGOA project. Finally, the last section contains the conclusions and findings of the project and recommendations for further work. 1.1 Background Aviation traffic is constantly expanding. Every now and then the development might stagnate, for example due to an event like the terror outrage in USA in 2001 or the SARS epidemic a few years back, but the prognosis for future aviation traffic remains upward. This also implies higher demands on the pilots as they are called on to use more and more technology more frequently. Meanwhile, airspace above dense population areas will be harder to gain access to by the general aviation sector because the commercial aviation sector will lay claim to more of that airspace. There will also be a greater demand on transponders and radio connections in use by all sectors of aviation. To maintain high level of safety improvements of the technical systems both onboard aircrafts and on the ground will have to be made. The current radar based

13 Air Navigation Services Division REPORT D-LFV (73) surveillance system and communication based on voice radio will not be sufficient to meet future needs as air traffic increases. A system that will work as a complement to and eventually substitute to the current radar system is, in all probability, ADS-B (Automatic Dependent Surveillance Broadcast). The principle is that every vessel in the air sends out its own position via a data link. All other aircrafts in the surroundings (if appropriate equipment is on board, and the active application allows it) as well as the ATC can present the data on their screens. The information can reach more users and is more accurate than the radar information of today. ADS-B is just one of the services that the data link supports. FIS-B (Flight Information Service Broadcast) is a service that can supply aircraft with, for example, weather information and/or other aeronautical information. The development of the technique has reached a stable level: it became ICAO standard November 2001, and is already in use. However, large-scale pre-operational tests are still required before the system can be put into operation and one of EGOA s goals is to involve the general aviation sector in this process. The project will focus on the demands that the general aviation sector has or could have in the future. The expectation of EGOA, which can be seen as an ADS-B and FIS-B preimplementation project, has been to be one step ahead of future possibilities for general aviation and in that way maintain access to controlled airspace for general aviation. Experiences from the EGOA project should be used to adjust the technology to fit the operations to avoid, at a later stage, having to of adjust the operations to fit the technology Summary of Safety Occurrence Reports To put the issues addressed in the EGOA project into perspective a summary of the Air Navigation Services Safety Occurrence Reports (ANS-DA) for the time January 2003-June 2006 can be found below. The summary found here addresses two types of Safety Occurrences; Flight in controlled airspace without clearance from ATC Runway incursion For flight in controlled airspace without clearance the number of reports are as follows: Year reports reports reports 2006 (January-June) 100 reports Number of occurrences Table 1 Safety Occurrence Reports for flight in controlled airspace without clearence.

14 Air Navigation Services Division REPORT D-LFV (73) In total this sums up to 720 reports on a three and a half year period. For runway incursions the number of reports is: Year Number of occurrences reports reports reports 2006 (January-June) 37 reports Table 2 Safety Occurrence Reports for runway incursions. In total this sums up to 133 reports on runway incursions during the same period. The summary above includes all Swedish airspace and all types of aircraft, commercial as well as general aviation. To give a hint about the proportion of general aviation aircraft being involved a closer look on the reports from Stockholm-Arlanda Airport ATC from January to September 2006 can be found below. Month (2006) Occurrences January-March No flights in controlled airspace without clearance reported. April May June July 1 flight in controlled airspace without clearance, aircraft not identified. No flights in controlled airspace without clearance reported. 4 flights in controlled airspace without clearance, three of these general aviation aircraft, the fourth not identified. 2 flights in controlled airspace without clearance, both general aviation aircraft. General Aviation Other August 3 flights in controlled Not identified

15 Air Navigation Services Division REPORT D-LFV (73) Month (2006) Occurrences September airspace without clearance, two of these general aviation aircraft, the third not identified 1 flight in controlled airspace without clearance, general aviation aircraft. General Aviation Other Total Not identified Table 3 Safety Occurrence Reports regarding flight in controlled airspace without clearance at Stockholm-Arlanda airport from January to September During the Swedish summer period, June to August, a peak of reports can be noticed. This time of year is typically also the peak time for leisure general aviation operations in Sweden. The weather usually allows VFR flights and noteveryday-pilots are more present in the airspace than during the winter period. The summary above indicates that general aviation aircraft are overrepresented in these types of incidents, even if more material would be needed to make it statistically valid. Hopefully, the conclusions in this report will find that the technique and applications addressed in the EGOA project can lower the number of Safety Occurrences like the ones above, avoiding having more restrictions on general aviation and being able to maintain access to controlled airspace to general aviation, in co-existence with commercial operators What are ADS-B, FIS-B and VDL Mode 4? For readers who are not familiar with the concept of ADS-B/FIS-B/VDL Mode 4, it is really recommended to read Appendix A before proceeding with this report. Appendix A contains explanations about the difference between the applications and the technique and will enhance the understanding of this report for those not familiar with the terms mentioned so far. 1.2 EGOA Project Objectives EGOA is a project that will provide experiences from ADS-B and FIS-B to both the general aviation community and to the air navigation service provider, in this case air traffic controllers and technical staff. The activities in the project should be so similar to operational use, without being so, so that the findings in the project can be directly used when implementing ADS-B and FIS-B for operational use. The project objectives can be summarised in the bullets below: To evaluate and validate ADS-B and FIS-B for general aviation pilots.

16 Air Navigation Services Division REPORT D-LFV (73) To evaluate and validate ADS-B in a mixed radar and ADS-B environment from a controller perspective. To show potential benefits with ADS-B for Search and Rescue. To spread knowledge about the about the issues addressed in the project and the proposed solutions to a wider audience within the aviation community. To provide experiences and input to standardisation efforts for ADS-B and FIS-B To provide knowledge, experiences and an infrastructure, ground as well as airborne, to be used by future research and implementations projects addressing ADS-B, FIS-B or other data link applications. 1.3 Scope of document This final report is written in a way that allows for someone not having heard of the EGOA project during the project lifetime from January 2003 to December 2005 still to be able to make use of the content. Some of the technical validation regarding availability etc will continue after this report as a part of the EUROCONTROL CASCADE CRISTAL Sweden programme and is not included in this release. 1.4 EGOA project group Project Manager and Technical Responsible Roger Li M.Sc. in Engineering Systems Engineer, LFV Norrköping LFV Management Representative Anne-Lovise Linge M.Sc. in Engineering Manager ANS Development, LFV Norrköping Operational Responsible Per Wilhelmsson Air Traffic Controller Malmen airport, Linköping Operational Assistant Daniel Duvskog Air Traffic Controller SAAB airport, Linköping General Aviation Community Contact Lars Holmström M.Sc. in Engineering Consultant, The Royal Swedish Aero Club, Stockholm

17 Air Navigation Services Division REPORT D-LFV (73) Validation and Evaluation Anders Erzell M.Sc. in Engineering Systems Engineer, LFV Norrköping Installations and Tests Per-Ola Kårbro Engineer and Flight Inspector, LFV Norrköping Safety Göran Hasslar B.Sc. in Aeronautical Engineering Systems Engineer, LFV Stockholm/Arlanda and Lars Danielson M.Sc. in Industrial Engineering and Management Independent Internal Assessor, LFV Norrköping Rules and Regulations Ann-Christine Sporrong Air Traffic Controller LFV Norrköping 1.5 Abbreviations ADS-B ANS ANS-DA ANSP ARCC ASD ATC ATCO ATS AW CDTI CNS CPR CTR CWP EGOA Automatic Dependent Sueveillance Broadcast Air Navigation Services ANS DriftAvvikelse (Safety Occurrence Report) Air Navigation Service Provider Air Rescue Coordination Center Air Situational Display Air Traffic Control Air Traffic Controller Air Traffic Services Aerial Work Cockpit Display of Traffic Information Communication, Navigation and Surveillance Compact Position Reporting Control Zone Controller Work Position Enhanced General aviation Operations by ADS-B

18 Air Navigation Services Division REPORT D-LFV (73) FIS-B H24 GA LFV MMCATS MMR MSL NEAN NUP PDA PRL RDP RPU SAR SMS STDMA TDMA TMA UAV VDL VFR VHF VMC ÖKC Flight Information Service - Broadcast Open 24 hours per day General Aviation Luftfartsverket Swedish Airports and Air Navigation Services Multi-Mode Carmenta Air Traffic Surveyor Multi-Mode Radio Mean Sea Level North European ADS-B Network NEAN Update Programme Personal Digital Assistant Prediction Line Radar data Display and Processing Radar Presentation Unit Search And Rescue Safety Management System Self-organised TDMA Time Division Multiple Access Terminal Area Unmanned Aerial Vehicle VHF Data Link Visual Flight Rules Very High Frequency Visual Metrological Conditions Östgöta Control Centre

19 Air Navigation Services Division REPORT D-LFV (73) 2 OPERATIONAL AND ENVIRONMENT DESCRIPTION 2.1 Environment The EGOA project was executed in Östgöta TMA, which is located in the southeastern part of Sweden. Östgöta TMA spans over two provinces, Östergötland in the south and Södermanland in the north. The TMA is rich in topographical diversity. You find the Baltic Sea in the east and Lake Vättern in the west. In the very south and in the Kolmården area just north of Norrköping the landscape becomes a bit more mountainous. North of Kolmården the terrain tends to flatten the further north you go. Kolmården holds a PSR, Primary Surveillance Radar, covering most of the TMA. South of Norrköping, you will find flat land and this is where Linköping/SAAB and Linköping/Malmen are situated. The climate in the TMA is in some ways affected by the Baltic Sea. The coastal climate gives Norrköping and Nyköping reasonably mild winters with an average temperature in January with -2 degrees Celsius and in July around 16 degrees Celsius while the Linköping area tends to have more of a continental climate that lowers the average temperature to -4 degrees Celsius in January and around 17 degrees Celsius in July. When it comes to precipitation the eastern parts gets around 700 mm per year and the western parts around 500 mm. 2.2 Airspace Terminal Area The TMA:s configuration is shown in Figure 1. The upper limit of the TMA is FL95 and the lower limit is 1600 ft MSL(in the additional TMA 4500 ft) Control Zones The Control Zones located inside Östgöta TMA stretches from Ground to 1600 ft MSL when active Sectors The TMA is divided in three main parts; Sector Nyköping, Sector Norrköping and Sector Linköping. 2.3 Airports Inside the TMA there are four controlled airports; Stockholm/Skavsta, Norrköping/Kungsängen, Linköping/SAAB and Linköping/Malmen. A control tower is located on each airport. A terminal control (Östgöta Control Centre) is located in Norrköping at Kungsängen airport. The terminal control has approach control to all airports in Östgöta TMA. When the terminal control is closed (mainly between midnight and 06.00) the approach control is executed from each tower if it is open.

20 Air Navigation Services Division REPORT D-LFV (73) A number of smaller, uncontrolled, airfields are located within the TMA Stockholm/Skavsta airport (ESKN) Stockholm/Skavsta airport is also called Nyköping/Skavsta. The airport is an old military airport (former 11 th wing of the Swedish Air Force). It was closed as a military airport in the 1980s and has in the recent years established it self as a very active low fare airport. The main actor at Skavsta is Ryan Air flying to several destinations in Europe. The airport is often used as alternate airport for traffic to Stockholm/Arlanda. The opening hours are H24. Other actors at the airport are SAAB Nyge Aero (operating as target flights for the military), The Swedish Coast Guard and a number of small general aviation aircraft (including a Parachute Club and a Flying Club) Norrköping/Kungsängen airport (ESSP) The Norrköping/Kungsängen airport is located in the eastern part of Norrköping. The airport has regular traffic to Stockholm and Copenhagen on daily bases. Charter aircraft uses the airport on a weekly basis. The airport also has a number of Flying Clubs (including Motored aircraft, Gliders and experimental aircraft). The opening hours of the airport are mainly between and on weekdays. When the airport (the tower) is closed the airspace is uncontrolled but the Flying Club can continue with its operations anyway Linköping/SAAB airport (ESSL) The SAAB/Linköping airport is located in the eastern part of Linköping. It is the base for the Swedish aircraft industry (SAAB) and has regular traffic to Stockholm and Copenhagen. The main actor on the airport during daytime is the military test flight unit at SAAB but the airport also holds one of the most active private Flying Clubs in Sweden. The opening hours of the airport are mainly between and on weekdays. When the airport (the tower) is closed, the airspace is uncontrolled but the Flying Club can continue with its operations anyway Linköping/Malmen airport (ESCF) The Linköping/Malmen airport is located in the western part of Linköping. The main actors at the airport are the Swedish Air Force Flight Academy, Helicopter Wing and Test Flight Unit. The airport holds a large number of Flying Clubs (including Gliders, Motored aircraft, experimental aircrafts and a Parachute Club) that are active mainly during weekends. The airport is open during weekdays between and The opening hours are stretched to during September to March.

21 Air Navigation Services Division REPORT D-LFV (73) Motala airfield The Motala airfield is located in the western part of the Östgöta TMA. The airfield is uncontrolled and has a grass field. It holds a Flying Club with both motor and glider activity Katrineholm airfield (ESVK) The Katrineholm airfield is located north of the Östgöta TMA. The airfield is uncontrolled and has a grass field. It holds a Flying Club with both motor and glider activity Finspång airfield. The Finspång airfield, located north of Linköping on the Östgöta TMA border, is an uncontrolled airfield. The Flying Club uses the grass field with motor activities. Figure 1 Östgöta TMA. With airports, airfields, sectors and controlzones displayed.

22 Air Navigation Services Division REPORT D-LFV (73) 2.4 Air Traffic Services The Östgöta Terminal Area holds three Air Traffic Service units listed below ATS Nyköping/Skavsta The unit executes Air Traffic Control service in Nyköping/Skavsta Control Zone H24. When the approach control (ÖKC) is closed, the tower also handles the approach control to the airport (in sector Nyköping) ATS Norrköping/Kungsängen The unit consists of Kungsängen Tower and Östgöta Control Centre. The Tower executes ATC in Norrköping/Kungsängen CTR when open. When the approach control (ÖKC) is closed, the tower also handles the approach control to the airport (in sector Norrköping). The Östgöta Control Centre handles approach control to all airports in Östgöta TMA when open (mainly between and 24.00) ATS Linköping The ATS consist of two towers; SAAB and Malmen. Each tower executes ATC in its CTR when open. When the approach control (ÖKC) is closed, each tower also handles the approach control to the airport (in sector Linköping). If both SAAB and Malmen are open when ÖKC is closed, SAAB tower executes the approach control in sector Linköping.

23 Air Navigation Services Division REPORT D-LFV (73) 3 PROJECT RELATED SAFETY WORK The EGOA project aimed for and also did perform flight trials under normal operational conditions. Therefore it was required by the Swedish Civil Aviation Authority to provide evidence that there would be no infringement in the safety of operations. 3.1 Preliminary Functional Hazard Assessment To identify possible hazards with respect to flight safety a functional hazard assessment according to LFV/ANS SMS manual were carried out before the trials began. The assessment focused on hazard connected to the following system elements: Pilot, Air traffic control officer, Technical system and its connection to the operational system, Procedure and test programme. A large group of experts in the different elements stated above had a brainstorming session to identify different possible hazards and make a risk classification. The result of the safety assessment was summarised in a PFHAreport, [1], and did also lead to a number of changes to the plan of the trials: To eliminate the risk of an ATCO using the ADS-B information for separation purposes in a stressed situation no equipment was to be placed in the vicinity of an operational position. It is important to compose and distribute material to inform the participants (pilots and ATCOs) what they are supposed to do and when and what they should not do, All evaluation should be done after the flight, not to remove the attention from flying or leading. The interface to the radar-data distribution system was analysed to reduce the risk of EGOA equipment to influence the operational system. By making the changes to the plans and installations the hazards were eliminated and the trials performed in line with the new plans. During the trials and logging of ADS-B data no safety infringements or new hazards were identified.

24 Air Navigation Services Division REPORT D-LFV (73) 4 TECHNICAL ARCHITECTURE 4.1 Aircraft and vehicles All aircraft or vehicles participating in the EGOA have been equipped with a VDL Mode 4 transceiver. Two different kind of transceivers from two different manufacturers have been used, one VDL-Mode-4-only transceiver, VDL4000/GA from CNS Systems AB, and one radio combining 8,33 MHz Voice and VDL Mode 4, the RTX6040 from RTX A/S. Figure 2 VDL4000/GA, VDL Mode 4 transceiver Figure 3 RTX6040, combined 8.33 Voice and VDL4 transceiver The VDL Mode 4 transceivers are connected to a VHF antenna and a GPS antenna. In most cases a combined VHF/GPS antenna have been used but in some cases, in gliders, separate VHF and GPS antennas have been used. The architecture of the two products are basically the same except for the voice part that is included in one of them: One GNSS receiver, two VHF receivers for VDL4, one VHF transmitter, a data processor for data de-/ and encoding and interfaces to avionics.

25 Air Navigation Services Division REPORT D-LFV (73) VDL Mode 4 TX VDL Mode 4 RX VDL Mode 4 RX DATA DE-/ENCODING AND DATA PROCESSING AIRCRAFT AVIONICS INTERFACE (e.g. CDTI, altitude encoder) GNSS RX Figure 4 Principal architecture of a VDL Mode 4 transceiver Added in the combined 8.33 MHz voice and VDL Mode 4 radio is yet another receiver for AM voice, a voice communication processing unit and a manmachine interface. AM-Voice RX VDL Mode 4 & AM-Voice TX VDL Mode 4 RX VDL Mode 4 RX VOICE COMMUNICATION PROCESSING DATA DE-/ENCODING AND DATA PROCESSING MAN-MACHINE- INTERFACE AND AIRCRAFT AVIONICS (e.g. CDTI, altitude encoder) GNSS RX Figure 5 Principal architecture of a combined 8.33 MHz voice and VDL Mode 4 transceiver In many of the aircraft participating in the project a Cockpit Display of Traffic Information (CDTI) has been used. The hardware used has been different Personal Digital Assistant (PDA) models from Hewlett Packard running versions of Windows Pocket PC operating system.

26 Air Navigation Services Division REPORT D-LFV (73) Figure 6. PDA with CDTI software The CDTI is connected to the VDL mode 4 transceiver via a RS232 serial interface. 4.2 Ground The ground infrastructure used for EGOA is shown on the TMA background in the figure below. Figure 7 Schematic view of Östgöta TMA and the EGOA ground installations The EGOA network consists of four VDL Mode 4 ground stations at the major airports in the TMA. Radar coverage is provided by the Askersund SSR. The third

27 Air Navigation Services Division REPORT D-LFV (73) major component of the system is the servers located at LFV HQ, for ADS-B and FIS-B services. VDL 4 Ground Station CDTI VIP VDL 4 mobile transceiver VDL 4 VDL 4 radio sub system VIP PC with Ground Station Functionality. VIP ASTERIX conversion ATC presentation equipment ASTERIX21 ADS-B Server ASTERIX21 Meteorology FIS-B Server system Figure 8 Principal architecture of EGOA system

28 Air Navigation Services Division REPORT D-LFV (73) 5 CONTROLLER ISSUES 5.1 Problem description The pilots and aircraft owners with ADS-B/VDL Mode 4 transceiver and CDTI equipped aircraft are the ones receiving the main benefits from the associated applications that the EGOA project have been evaluating. However the controller can also benefit from the installed equipment. The project identified a number of issues to focus on: ADS-B functionality for the CWP HMI How does the Situational Awareness for the ATCO change as ADS-B is introduced for general aviation aircraft? Will ADS-B introduction for general aviation aircraft affect the workload produced by general aviation for the ATCO? Spread knowledge about ADS-B, FIS-B and VDL mode 4 among ATCO:s How can ADS-B improve the Search and Rescue operations from a ATCO:s point of view? How will an introduction of ADS-B in military aircraft affect the ATCO:s? 5.2 Methods The ATC presentation equipment used in EGOA has been running in shadow mode only for observation purpose, placed aside from ordinary Controller Working Position (CWP). This is based on safety considerations, uncertified equipment must not be used for operational work, nor interfere with operational work or operational equipment. Due to the above, it has been somewhat difficult to transfer the experiences made during the project to real operational experience. The operational result is thus based on observations, theoretical studies and discussions made in cooperation with controllers at the involved ATS units. 5.3 Verification and Validation HMI Two different Air Situational Displays have been used in the EGOA project; RDP (Produced by Aerotech Telub. Installed at Skavsta, SAAB and Malmen) and RPU (Produced by Imentum. Installed at ÖKC). The equipment has been available for the controllers to observe for approximately one year.

29 Air Navigation Services Division REPORT D-LFV (73) RDP/RPU The RDP runs with a version called and is basically the same version used in the early stages of the Kiruna implementation project (NUP). The RDP has been installed in three towers (Skavsta, SAAB and Malmen) during the project. Because of different problems (lack of space at Skavsta and poor data connection at Malmen) the SAAB RDP has been the one that has produced the most time up and running. The RPU is installed as stand-alone equipment at ÖKC and except for some connection problems during the start-up phase, the RPU has worked well during the evaluation. The following observations have been noted in both systems: a) Wrong length of historical tail The number of historical plots behind an ADS-B target calculated in the same way as for SSR targets. (The number of historical plots is set in a user menu. When a value is set, for example 5, it means that the last 5 positions received from the transponder are shown on the ASD. The problem is that the SSR transponder is updated once every sixth second and the ADS-B transceiver broadcast its position every second. This mean that 5 historical plots behind a SSR target is equal to 5x6=30 seconds of flight and 5 plots behind a ADS-B target is equal to 5x1=5 seconds of flight. The aircraft may fly at the same speed but the length of the historical tail is different. This can easily cause the ATCO to believe that the aircraft have totally different speed.) The problem could be easily solved either by showing (using the example above) 1x30=30 historical plots behind ADS-B targets or by showing every sixth ADS-B position (1x30/6=5). However there is a third solution that make it possible for the controller to get the benefits from a high update rate and at the same time get a correct view of the aircraft speed (ADS-B is updated every second in the EGOA case. It may vary depending on where you are in the flight loop. For example it may be enough with 1 update every 6 second for enroute traffic). In this solution the first six ADS-B positions will always be plotted and after this every sixth position. The total length of the historical tail will be the same for both SSR and ADS-B targets to give the controller the right feeling of speed.

30 Air Navigation Services Division REPORT D-LFV (73) Figure 9 Suggestion to solve problem with historical plots. b) New Colours introduced in labels When ADS-B is introduced in the RDP and RPU, it comes with a number of new colours in the label set up. As an example, all ADS-B derived information in the label is marked with a green colour (in a SSR label all information is presented in the same colour). Other colours are used to show deviations between ADS-B and SSR information, emergency warnings and so on. The RDP give the local administrator of the system a lot of possibilities to change the colour set of the ASD. This has been noted in the many different configurations today in RDP-towers. The local administrator right is given to one person on each ATS using RDP and he/she is the only one that can change the colour setup. He/she can define a number of different colour sets that can be used by the ATCO:s in the operational work. The RPU allows the user to change the colours on the ASD by moving three levers in a user menu. This gives the user an endless number of different colour sets. The colour sets shall be approved by LFV before they are used (to check that no colour conflicts are discovered, for example if the colour of the label is the same as for a restricted area ). The problem is that there is no function at LFV that can approve such colour sets. As more colours are introduced in the label, the importances of which background colours are used are raised. If a number of predefined colour sets are made available for the ATCO:s, the risk of colour conflicts is reduced. The colour sets shall be produced in close cooperation with operational ATCO:s in both TWR:s and TMC:s as the demands on colour sets can vary.

31 Air Navigation Services Division REPORT D-LFV (73) c) Double labels presented from same aircraft When an aircraft is equipped with both ADS-B and SSR transponder, a fused label is presented to the ATCO on the ASD. A number of parameters must be fulfilled before the fused target is presented (the positions may not differ more than a pre defined value, the SSR code must be associated with a callsign). If the parameters are not fulfilled, both SSR and ADS-B targets are presented. In Östgöta TMA the towers and the approach control disposes a number of transponder codes (SSR) for local flights. The codes are used for aircraft that calls up without a flight plan. The SSR-callsign association is normally made only by the ATC unit that has assigned the code to the aircraft. This leads to that all other ATC units has two labels for the aircraft. The double labels can be irritating for ATCO:s and give a feeling of uncertainty of how many aircraft are presented on the screen. The problem can be solved in some different ways; The SSR code that has bees assigned to the aircraft is fed into the ADS-B transceiver and broadcasted to the ground. The ground equipment can then make the fused target based on this information. No association with flight plans must be made. All transponder codes are distributed from a central position and all associations are distributed to all ATC units. (Not a very realistic solution) d) No double code warning exists for ADS-B targets If callsign (i.e. flight number) is to be set at the flight deck it is possible that wrong callsign is set and transmitted by the aircraft. If another aircraft transmits the same callsign a double code warning should be issued to the controller. e) No warning if an aircraft has two valid flightplans at the same time If the call sign is derived from the flight plan, it will be possible that a short turn around on the ground can result in wrong flight plan association. (The aircraft does not change its transponder code as is the case today. It associates by the ICAO code, which is the same at all time. It depends on what value is set before an aircraft drops out of coast list.) To prevent this, a warning should be issued when there are more than one flight plan for an aircraft in a specified time. The controller must then make a manual association with the correct flight plan

32 Air Navigation Services Division REPORT D-LFV (73) f) Turn rate Prediction Line The turn rate prediction line has not been considered useful at this stage. As long as the aircraft does not transmit to which heading it is turning, there is no use to see a bended PRL. If the ADS-B transceiver can transmit to which heading the aircraft is turning (via the autopilot?) and by which turn rate, the information can be useful. g) Presentation of Aircraft Formations If a formation (for example a twoship / pair) of aircraft is presented on the ASD a new problem occurs. Today s normal procedures are that only the leading aircraft has its SSR transponder activated. If both aircraft are ADS- B equipped both aircraft will be shown on the ASD. It should be possible for the ATCO to switch off the label for an aircraft while flying in a formation to avoid to many aircraft presented at the same position. h) Met report presented on RDP/RPU Today s version of the RDP lacks the possibility to present a Metreport on the ASD. There has been noted a need in some towers to present the Met report on the RDP and doing this would reduce the need for displays in the CWP by one screen in some towers. The AWOS (or other used equipment) can be placed anywhere in the tower instead of in the already crowded CWP. It would be preferable if a widescreen were used for the RDP to allow that the size of the ASD still is acceptable. On the RPU on the other hand, the Met report is already implemented on the ASD, giving the user this advantage. i) Filter on 2 nd Air Situational Display (ASD) It must be possible to filter the information in a 2 nd ASD in the same way independent of the main ASD. If vehicles on the ground are equipped with ADS-B transceivers they are visible on the ASD. If a filter is set to, say 50 feet, the vehicles are removed from the ASD. However, if a 2 nd ASD shall be used to show the ground traffic, the filter must be turned off or set differently in this view Situational Awareness It has been impossible to verify if the situational awareness have become higher as a result of the introduction of ADS-B for general aviation aircraft in Östgöta TMA. The reason for this is that the information has not been for operational use.

33 Air Navigation Services Division REPORT D-LFV (73) However it can be assumed that the higher number of transceiver equipped aircraft would affect the situational awareness in a positive way. (The lower weight and power consumption has opened the door for experimental aircraft and gliders to install transceivers. Many of these aircraft has not been presented to the ATCO:s radar screens because the lack of SSR transponders.) In some control zones there are more than one airport (often smaller general aviation airfields). This is the case in Linköping where both Malmen and SAAB airports are located. Malmen airport is often closed during weekends and evenings. When Malmen is closed, SAAB tower take over the airspace over Malmen airport. The general aviation aircraft at Malmen are allowed to operate without ATS at Malmen. As a lot of general aviation aircraft at Malmen have become ADS-B equipped, the controllers at SAAB have observed the aircraft at Malmen from the moment they turn the main power on. This would probably, if operational, give the controller at SAAB a better way to plan his/her traffic Can ADS-B give general aviation more access to controlled airspace? Some categories of general aviation aircraft will probably get better access to controlled airspace as they get ADS-B equipped. The aircraft this concerns are mainly gliders and experimental aircraft (aircraft that often lack SSRtransponder). The main issue is to make the aircraft visible to the controller on the air situational display. If the aircraft is not visible, the controller has to block an entire sector only for one aircraft. If the aircraft is visible, the controller can separate directly to the actual position of the aircraft Workload The introduction of ADS-B and FIS-B for general aviation aircraft in Östgöta TMA would probably affect the workload for the ATCO:s if it became operational. It is how ever difficult to predict if it will lower or raise the total workload. The following scenarios are possible; More general aviation aircraft becomes transceiver equipped (ADS-B). Gliders and other aircraft (that has not been SSR-equipped) can get access to the TMA more easily than is the case of today. The ATCO can separate to the actual aircraft instead of to blocked sectors. This would probably mean a slight reduction of the ATCO workload compared to the present situation. The aircraft that are SSR equipped today is not expected to change the workload situation (for the ATCO:s) as they gets ADS-B transceivers. Many aircraft that lacks SSR transponders today operate below the TMA. If these aircraft get ADS-B transceiver equipped they may want to climb up into the TMA every now and then. This could lead to a slight increase of the workload for the ATCO:s.

34 Air Navigation Services Division REPORT D-LFV (73) At, for example, Malmen airport there is a high activity of gliders and experimental aircraft in evenings and weekends. A high percentage of these aircraft are not SSR equipped. If these aircraft were ADS-B equipped, the workload (derived from these flights) would most likely be slightly reduced. If Met report is distributed via FIS-B (as a kind of ATIS), and used operationally, it will most likely reduce the ATCO:s workload slightly. The radio traffic time will become slightly lower per aircraft. The Met report will not be read by the ATCO on the frequency, instead the pilot will receive the valid Met report at the CDTI. The pilot then tells the ATCO which version he has received and also the QNH at first contact. The workload would most likely be affected more at an Approach Control than in a Tower. The reason is that the Tower often reads a shortened version of the Met report; Wind, Runway in use and QNH (see Appendix 1 for examples). At the Approach control the whole Met report is read to all IFR aircraft and can therefore save more time on a FIS-B Met report (see Appendix 1 for examples). The result achieved with Met report via FIS-B can be thought to be the same as if the Met report is distributed via ATIS but there is an obvious advantage with the FIS-B Met report; it is received in text form automatically. It requires no frequency change and does not have to be written down. It is also possible to receive Met reports from different airports at the same time. The approximated radio time for each alternative was measured by timing an ATCO that read the text as it would have been read in an operational situation (with perfect conditions). The results that can be seen are that if the Met report is distributed via FIS- B reduces the radio traffic time by up to 50 %. The result would have been the same using conventional ATIS but would probably mean a slightly higher workload in the cockpit due to frequency changes and possibly writing the Met report down. The radio traffic time is often used as a metric in measuring the ATCO workload and the examples above would indicate a reduction in the workload for the ATCO and the Pilot if Met report via FIS-B is used Spread Knowledge about ADS-B, FIS-B and VDL mode 4 A major part of the EGOA project has been to spread information and knowledge about ADS-B, FIS-B and VDL mode 4. During the project all ATC units have been informed about the EGOA project in one way or another. Some units have been informed at a special meeting and some by information in paper form. EGOA representatives have visited all units several times to discuss ADS-B and FIS-B.

35 Air Navigation Services Division REPORT D-LFV (73) The ATCO:s at the participating ATC units are generally positive to the new technique. The average ATCO is however not very interested in the technique behind the plot. The most important issue for the controllers is that the received information can be guaranteed to be as safe to use as radar. The ATCO:s have not been able to use the technique operationally but can see the advantages it can give them.

36 Air Navigation Services Division REPORT D-LFV (73) 6 PILOT AND AIRCRAFT OWNER ISSUES 6.1 Problem description The largest number of aircraft belongs to the category general aviation (GA). Many of these aircraft are operated in Visual Metrological Conditions (VMC) following the Visual Flight Rules (VFR). Metrological conditions are in many situations limiting the operations of general aviation aircraft especially as many general aviation pilots are not qualified to fly only using instruments. New technology including GPS and moving map displays has made navigation much simpler and safer. However the full use of new technology is not yet possible because lack of certain components like data links and lack of regulations permitting the full use of the equipment. The most important expectations from the general aviation community are as follows: SAFETY; Flight safety must as traffic increases be maintained at a high level and be improved further. USER FRIENDLINESS; All systems and equipment must be simple to use and operate. Most pilots are not professional pilots. COST EFFECTIVENESS; the cost to own and operate a general aviation aircraft must be lowered. The introduction of new technology should allow removing older techniques equipment that is mandatory today and whose functionality can be catered for by the new technology. ACCESS TO AIRSPACE; to have maintained and increased access to controlled airspace and to be able to share this airspace with commercial airlines even as air traffic increases. It is the strong belief of the EGOA project that the data link concept evaluated within the project will be able to contribute to the fulfilment of all of the expectations above. The following section, 6.2, describes what methods that have been used to try to confirm this belief and section 6.3 contains a validation of the outcome of the airborne part of the trial period. 6.2 Method The method that has been used to evaluate the ADS-B and FIS-B applications has been to install equipment in approximately 25 general aviation aircraft. Comments from general aviation pilots have been collected regularly and evaluated in parallel with analysis of logged flight data. The technical issues regarding VDL mode 4 has for years been tested and proved in small and large aircraft in other projects, in the EGOA project the focus is on the operational aspects. The issues to be tested and evaluated in the EGOA project are several. Enhanced situation awareness using the supplied equipment.

37 Air Navigation Services Division REPORT D-LFV (73) Fleet management and follow up of flown paths in airspace, e.g. for flying clubs. Prevention of accidental incursion of restricted airspace and unauthorized incursion of controlled airspace. Runway Incursion prevented by using the supplied equipment. Distribution of requested flight information including weather observations, information of radio frequencies to ATC/TWR etc (FIS-B). Pilot and controller interaction. Functional test of supplied new equipment, both ADS-B/VDL Mode 4 transceiver and CDTI. Various types of aircraft and aircraft owners are represented in the EGOA project. Single seat to six seated aircraft are used. Privately owned and business owned aircraft are included as well as aircraft belonging to a flying club or a glider club. Some aircraft are classified as experimental aircraft and others are classified as normal category aircraft. Participating aircraft: Experimental category 8 Normal category Piper Normal category Tobago 1 Gliders 2 The EGOA-project has as a part of the project supplied all participating aircraft with an ADS-B/VDL mode 4 transceiver. Some transceivers are multimode radio which also can serve as a VHF voice communication radio with 8.33 MHz channel spacing in addition to the data link capability. Most aircraft have a display (CDTI) in the cockpit with a moving map showing own position, track and speed. Other ADS-B/VDL mode 4 equipped aircraft and ground stations are also shown with their ID/call sign on the display. Flying clubs and others on the ground are able to follow the aircraft flying in the test area by using an internet connected PC with a presentation software from the company Carmenta AB. The name of the software is Multi Mode Carmenta Air Traffic Surveyor (MMCATS) ADS-B/VDL mode 4 Transceiver All participating aircraft are equipped with an ADS-B/VDL mode 4 transceiver. A combined GPS/VHF antenna and cabling for antennas and power connection are included. A pressure sensor to provide pressure altitude information is also supplied.

38 Air Navigation Services Division REPORT D-LFV (73) Installation of the equipment in the experimental aircraft has been made by the aircraft owners/pilot and for the normal category aircraft by a certified maintenance company. Two types of transceivers are used in the EGOA-project. The transceiver type CNS VDL 4000/GA with pressure transducer is installed in the baggage compartment of the aircraft. A metal cover is used and a power cable is connected to a switch on the instrument panel. Aircraft with transceiver type RTX 6040 VHF-VDL Multi Mode Radio has the unit installed in the instrument panel. The GPS/VHF antenna is normally placed on the upper part of the fuselage. The intention has been that the VDL mode 4 transceiver will help to meet several of the expectations of the general aviation community as indicated in section 6.1: SAFETY and ACCESS TO AIRSPACE by providing continuous surveillance information to ATC. USER FRIENDLINESS The transceiver operates automatically. The pilot is normally not required to attend to the system. COST EFFECTIVENESS by encompassing a number of functions in one piece of equipment CDTI Two methods have been used for verification and validation of the CDTI. First of all, in parallel with the development of the CDTI software an evaluation report of the CDTI [3] was done at Linköping University. The report is available in Swedish on the EGOA website The work included risk identification both at micro and macro level. Micro matters as lay out of symbols, colures, the design of push bottoms and macro matters as pilot s reaction to various indications of aircraft on the CDTI compared with head up observations of traffic. The split responsibility between pilot in command and the ground controller for maintaining of the situational awareness is also noted and discussed. CDTI simulations with real pilots were also a part of the work. To the extent possible the feedback from the findings by University were used during the continuing development of the CDTI software. Secondly, the CDTI (Cockpit Display Traffic Information) display has been used in eleven of the aircraft. The hardware has been different models of HP ipaq running Windows Pocket PC as operating system. It has been installed on the instrument panel or used in a more flexible way. It is operated on internal batteries and has a data cable to the transceiver front panel connector. The display window measures 55 x 77 mm. There are four pre-programmed buttons on the display. Functions are Zoom +/-, Heading up or North up and met report. The pilot can monitor the position of own aircraft and the ground track on a moving map. This is displayed as a speed vector and shown in digital form. Other equipped aircraft are also displayed with an identity label. The map is automatically moved so that own aircraft is centred on the display. Map is turned so that north is up or ground track is up whichever is selected.

39 Air Navigation Services Division REPORT D-LFV (73) Runways are shown in detail assisting ground movement and showing runway incursion. An alarm is showed on the map with a red coloured runway and the text INCURSION (see Figure 10). Figure 10 CDTI with Runway Incursion warning Geographical information as water, forests, roads, built-up areas colours etc can be selected. Control Zones, Restricted areas etc are shown (see Figure 11). Figure 11 CDTI with moving map and CTR Zone information

40 Air Navigation Services Division REPORT D-LFV (73) The map can be zoomed up or down to give an optimal scale. Simple flight planning can be made and shown on the display. The pilot can press a button on the CDTI to request meteorological information from certain Ground stations. The met report is displayed as text on the screen (see Figure 12). Figure 12 CDTI in MET REPORT mode The intention has been that the CDTI will help to meet several of the expectations of the general aviation community as indicated in section 6.1: SAFETY by providing situational awareness to the pilot and by providing continuously updated weather information from surrounding airports. USER FRIENDLINESS by the moving map mode demanding a minimum of interaction between the CDTI and pilot. By easy availability to most common functions via four hardware buttons on the CDTI. By using to many people well known commercial hardware in form of PDA:s and using an operating system, Windows Pocket PC, closely related to Windows versions for ordinary PC:s. COST EFFECTIVENESS by using off-the-shelf hardware available almost anywhere at very low prices Other Flying clubs and others has been offered a presentation software called MMCATS. This software is provided by the EGOA project and is installed in the PC used by the flying club.

41 Air Navigation Services Division REPORT D-LFV (73) Figure 13. Multimode CATS - Flying Club presentation software Through an internet connection to the ground network ADS-B information can be received, displayed and recorded. Fleet management and follow up of flight training can be made. Recording of flown track can be analysed by student and instructor after the flight. Missing aircraft can be traced and last known position found. As with the VDL mode transceiver and the CDTI, the EGOA project s intention has been that the MMCATS presentation software will help to meet several of the expectations of the general aviation community as indicated in section 6.1: SAFETY by enabling presentation and recording of flights for support in search and rescue activities. For educational purposes at flight schools by enabling follow-up on recorded flights. USER FRIENDLINESS by using a software intuitive human-machineinterface and an ordinary PC with internet connection. COST EFFECTIVENESS enabling fleet management applications for flying clubs with many aircraft, optimizing the use of the aircraft fleet, keeping exact track of flying time per aircraft etc. 6.3 Verification and Validation The first EGOA aircraft to be equipped with an ADS-B/VDL mode 4 transceiver were the experimental category aircraft. From August 2004 most of these aircraft use the EGOA-supplied equipment on all flights.

42 Air Navigation Services Division REPORT D-LFV (73) Some time later the normal category aircraft were equipped and joined the fleet of aircraft which could be monitored by the ground receivers. During late 2004 and early 2005 the CDTI:s were distributed to those aircraft owners who had flagged their interest. The accumulated flying time during the period since August 2004 until the end of the EGOA project (December 2005) is impressive. The following observations has been noted ADS-B/VDL mode 4 Transceiver. As mentioned previous the focus in the EGOA project has been on operational issues not on technical ones. Since the ADS-B, FIS-B and data link functionality is transparent to the pilot as the transceiver is concerned there are limited input regarding this. However the aircraft transceivers from both manufacturers has proved to be technically reliable. This confirms previous findings from other projects. A few deviations from normal behaviour have been noted, these have been explained and have in most cases been caused by an inaccurate installation. Conclusions from pilot input are that the transceivers have had no negative impact on operations. If being allowed to use operational, the pilots opinion is that the transceiver could very well be a way to fulfil the expectations previously mentioned: SAFETY and ACCESS TO AIRSPACE by providing continuous surveillance information to ATC. USER FRIENDLINESS The transceiver operates automatically. The pilot is normally not required to attend to the system. COST EFFECTIVENESS by encompassing a number of functions in one piece of equipment. The last bullet, cost effectiveness, is considered especially valid by the pilots for the multi mode radio type, like the RTX6040, that also houses a VHF voice COM radio CDTI Both the evaluation report of the CDTI done at Linköping University in the development phase of the CDTI software and the validation done by the pilots using the CDTI have come to similar findings. Taking both parties findings, listed below, into account the following conclusions can be drawn regarding the CDTI s fulfilment of the general aviation community s expectations: SAFETY could be fulfilled by providing situational awareness to the pilot and by providing continuously updated weather information from surrounding airports but not with the current hardware. The PDAs is

43 Air Navigation Services Division REPORT D-LFV (73) considered too small, having poor brightness and being too unstable to be used in a cockpit environment. Complaints are mostly related to the hardware though, not the software or the CDTI concept in itself. USER FRIENDLINESS same conclusion as on safety with a better hardware and possibly another operating system user friendliness could be achieved. The current displays considered too small to be able use and manoeuvre easily. COST EFFECTIVENESS Not fulfilled with the current hardware. Despite low cost it is not seen as effective since the hardware is not suitable for cockpit use. The university report s and participating pilots findings are presented below, first the findings from the university report: University report findings Pilots taking part in the study regard the CDTI as an important that could improve flight safety if properly designed and properly used. Head-Down time is increased but better navigation and improved situational awareness compensate it. The size of the CDTI is important. The selected display is too small. It is important to design symbols and use colours so that the pilots can associate the symbol to known objects. The CDTI used in the EGOA project needs further improvements in this area. An aircraft on the display should resemble an aircraft. A VOR station should be shown on the display in a way normally used on aeronautical charts etc. Colour is important and should indicate degree of importance and criticality Pilot findings From the pilot point of view the CDTI is very important. It can be used to verify that the navigation based on VFR observations is correct. Other aircraft can be observed on distances longer than what the visual range permits. This is very useful when a group of aircraft is travelling in a loose formation and wants to maintain contact during the flight. This is an important feature to increase the flight safety. The met report feature of the system is seen to be an important option. Though it has only been tested in a small scale yet by a few pilots towards the end of project. The same goes for the possibility to observe special airspace as terminal areas, restricted airspace, TWR frequencies etc on the moving map on the CDTI. Most pilots report difficulty to monitor the display in the cockpit due to its small size, glare and lack of sufficient brightness.

44 Air Navigation Services Division REPORT D-LFV (73) The pilot can be distracted when flying by operating the small buttons on the display. The software should be more resistant to faulty fingering by the pilot. The CDTI hardware in form of PDA is not considered stable enough to be used operational in a cockpit environment Other The MMCATS software described above and used by flying clubs is much appreciated. It is used to monitor club member flights and by flying instructors. A number of times single flying students has been assisted by using the system to follow up a flight in progress or later of the recorded flight path. Flights where navigational errors occurred has been carefully studied and analyzed. A number of demonstrations of the system have been organized. The MMCATS has performed well and shown the potential of the ADS-B/VDL mode 4 concept. The expectations mentioned in section regarding: SAFETY can be considered to be fulfilled by enabling presentation and recording of flights for follow-up on incidents. The same goes for educational purposes at the flight schools by enabling follow-up on recorded flights. Support in search and rescue activities has luckily enough not been needed. USER FRIENDLINESS by using a software intuitive human-machineinterface can also be considered to be fulfilled. COST EFFECTIVENESS by enabling fleet management applications for flying clubs with many aircraft, optimizing the use of the aircraft fleet, keeping exact track of flying time per aircraft etc has also proven to be fulfilled. This would naturally be even more useful with nation-wide ground station coverage, not only in Östgöta TMA as has been the case during the EGOA project.

45 Air Navigation Services Division REPORT D-LFV (73) 7 GROUND INFRASTRUCTURE ISSUES This section contains issues related to the ground infrastructure. The ground infrastructure is not the first concern of the general aviation community but for the Air Navigation Service Provider (ANSP) the ground infrastructure s performance and the costs associated with it are very important. In this section the aim is to show whether it is possible to achieve a ground infrastructure with better performance than today s system but at significantly lower cost. 7.1 Problem description Today the air traffic surveillance in Östgöta TMA is performed with Secondary Surveillance Radar (SSR) as the primary source of surveillance information. At the four airports involved in the EGOA project surveillance on the airport surface is done by visual acquisition by the air traffic controllers in the tower and by voice communication between air traffic controllers and pilots over VHF. The SSR does not provide surveillance coverage all the way down to the airport surface and no surface movement radars (SMR) exist at any of the four airports. All other information such as weather, runway in use etc, are provided via voice communication. No system such as Digital ATIS or similar is available in todays operations at any of the four airports. The challenge for the EGOA project has been to find out if the following can be provided; LOW ALTITUDE SURVEILLANCE AIRPORT SURFACE SURVEILLANCE DIGITAL IN-FLIGHT AERONAUTICAL INFORMATION The purpose of the two first bullets above is to maintain and to increase the air traffic safety, this done without having the large investment and maintenance costs for the ANSP that are associated with the current radar systems. Regarding the last bullet such services are provided today at larger airports by providers such as ARINC or SITA but are then associated with a cost for the users. 7.2 Method To find out whether ADS-B and FIS-B via VDL mode 4 can provide the low altitude surveillance, airport surface surveillance and in-flight aeronautical information, four VDL Mode 4 ground stations have been installed at the four airports. As seen in Figure 8 the ground stations used in the EGOA project are not full-scale ground stations. The ground stations used in EGOA consists of a VDL mode 4 transceiver connected to PC containing software that provides ground station functionality such as conversion from VDL mode 4 data format to ASTERIX format and handling the communication with the other parts of the ground system such as ADS-B server and FIS-B server. Time reference system,

46 Air Navigation Services Division REPORT D-LFV (73) differential GNSS (GNS-B), TIS-B functionality and the redundancy that are provided by a commercial full-scale VDL mode 4 station have not been available in EGOA which should be kept in mind when validating the ground system performance. A ground system with full-scale ground stations could certainly be assumed to improve whatever the performance of the EGOA test ground system. All ADS-B data received by the four ground stations have been forwarded to a central logging server where SSR data from the Askersund SSR also have been logged. The main parameter that has been looked at when validating the ground system is coverage, ADS-B coverage and comparison between ADS-B and SSR coverage. It should be noted that where there is ADS-B coverage there is also FIS-B coverage since the same ground station facilitates these two services. The availability of the ground system has not been analysed in the project. This is due to the fact mentioned above that the ground stations are only temporary set ups, not providing the redundancy, monitoring and control functionality that would be needed to do a fair analysis of the system availability. The position accuracy in the ground-based part of the system is directly connected to the GPS performance. A short note about accuracy on the airport surface is found in section Issues related to the ATC display equipment are covered in section 5. The expected coverage of combined ADS-B and SSR is illustrated in Figure 14. The coverage calculations are based on theoretical line of sight calculations and do not take terrain or obstacles into account. The minimum levels of expected coverage indicated Figure 14 is based on distance circles of 25, 50 and 75 NM from Askersund SSR and the four airports. In airspace where both ADS-B and SSR coverage can be expected data from the two different sources have been combined and compared.

47 Air Navigation Services Division REPORT D-LFV (73) Figure 14 SSR and ADS-B coverage. The coloured areas indicate the expected coverage of combined ADS-B and SSR coverage above 250 ft, 1300 ft and 2800 ft respectively. 7.3 Verification and Validation The validation is based on data of opportunity traffic with aircrafts participating in EGOA and the flight inspection aircrafts in Östgöta TMA and surrounding airspace. The validation includes aircrafts plots recorded between and and consists of a total of plots that corresponds approximately 1500 hours of effective flight time. The performance parameters taken into account in EGOA are availabilty, ADS-B coverage, ADS-B coverage compared to SSR coverage and position accuracy. More elaborate analysis of the performance of ADS-B in Östgöta TMA based on the equipment installed during the EGOA project will be conducted in the CRISTAL Validation Exercises in Sweden project.

48 Air Navigation Services Division REPORT D-LFV (73) Coverage The coverage of the four ground stations in Östgöta TMA and the airspace below is good, as indicated in the following sections. When comparing the expected coverage based on line-of-sight calculations the outcome reported in the sections below is in line with what could be expected. To verify the coverage in Östgöta TMA logged data from opportunity traffic and from the live demonstrations organised within the EGOA project have been used. When comparing ADS-B and SSR coverage, see section , the benefits for ATC is clearly visible, especially at low altitude. This could also have a positive impact on the use of ADS-B for SAR purposes Overall Coverage Figure 15 shows all plots recorded in the EGOA network during the time period between and The plot pattern presents an estimation of the coverage that could be expected from a ground station in Östgöta TMA. The major limiting factor in this dataset is line-of-sight, only in some cases distortion could be the expected cause of failure. The straight tracks in the plot are recorded data from the two flight inspection aircrafts operated by LFV, on ferry they usually fly at FL250. Based on the recorded data without correlation to flight plan, the EGOA network provides ADS-B coverage in exceeding of 180 NM at FL 250.

49 Air Navigation Services Division REPORT D-LFV (73) Figure 15 ADS-B coverage by the EGOA network Low Altitude and Airport Surface Coverage The ADS-B service provides good low altitude coverage around the ground stations. ADS-B is based on cooperative sensors and one ADS-B ground station can provide continuous coverage from en-route altitude all the way down to the apron. Figure 16 shows the plot pattern with focus on the control zones around the two airports in Linköping. The exit and entry points to the control zone where the traffic converges are clearly visible in the picture.

50 Air Navigation Services Division REPORT D-LFV (73) Figure 16 Linköping and Malmen Control Zones Continuous surveillance coverage especially at low altitude is a critical aspect for ATC surveillance and could provide a complement to or alternative to conventional SSR.

51 Air Navigation Services Division REPORT D-LFV (73) Figure 17 Linköping Airport and the pattern of touch and go trials by the training at Linköping Flight Club. The taxi way and apron to the Flight Club is clearly visible in the plots. Figure 17 shows the plot pattern over Linköping Airport and the touch-and-go patterns caused by the schooling are clearly visible in the plot. The other three airports have produced similar results but Linköping has been chosen for illustration since this airport houses the largest number of ADS-B equipped aircraft. Based on what is presented in this section, and further proven in the following subsections of section 7.3, it is the conclusion that the desired services: LOW ALTITUDE SURVEILLANCE AIRPORT SURFACE SURVEILLANCE DIGITAL IN-FLIGHT AERONAUTICAL INFORMATION via ADS-B and FIS-B can be provided by the use of VDL mode 4 technology. The surveillance provided via ADS-B at a significantly lower ground infrastructure cost for the Air Navigation Service Provider (ANSP) than with conventional radar. The digital in-flight aeronautical information, which only have been available to commercial airlines charged by ARINC or SITA before, can be available to general aviation via FIS-B, using the same airborne VDL mode 4 equipment as for ADS-B.

52 Air Navigation Services Division REPORT D-LFV (73) Coverage Below 500 ft 1 Figure 18 shows the coverage below 500 ft, scattered plots in the entire TMA indicates that coverage below 500 ft is achieved in the major area of the TMA. The plot pattern contains approximately plots, most of which is located around the airports, with the exception of the area south of Norrköping and east of Linköping. The data is extracted by applying an upper altitude filter to the data; this results in scattered tracks, with no adjacent plots. This is due to the altitude filtering when an aircraft track enters and exits the volume of interest. Therefore no conclusions on update probability or continuity could be made on this data. Altitudes below 500 ft are not used extensively outside the control zones, therefore no definitive conclusion of coverage in the entire TMA can be drawn from the opportunity traffic log data. To verify low-level coverage in the airspace below the TMA planned test flights need to be performed. Figure 18 Plot pattern indicating coverage below 500ft 1 The altitudes in ADS-B reports are based on barometric altitude if such is available, therefore the limit 500ft should be seen as a floating limit depending on barometric pressure. The assessment includes a wide range of individual aircrafts using reports from several consecutive weeks and should provide a good value for estimating the coverage below 500 ft MSL.

53 LFV Air Navigation Services Division Prepared by Approved by ASD/DEV Roger Li, Document Document id Page REPORT D-LFV (73) Date Ver.rev Reference 19 November LFV When compared to the coverage estimation, (Figure 14), the collected data indicates that below 500 ft the Control Zones and a large portion of the airspace outside the Control Zones have ADS-B ground station coverage Coverage between 500ft and 1300ft In Figure 19 the plot pattern shows the coverage between 500 ft and 1300 ft, the plot pattern contains approximately plots. Figure 19 Plot pattern indicating coverage between 500 ft and 1300 ft The plot pattern in Figure 19 supports the line-of-sight calculations in Figure 14 saying that the TMA is covered from 500 ft and upwards. The phenomena of scattered tracks with no adjacent plots occur in this set of data but are not as apparent as for the data set altitude filtered below 500 ft. Based on the plot pattern we can assume coverage across the coastline towards the Baltic Sea in the east, to the southern parts of Stockholm in the north and across Lake Vättern in the west. This corresponds well to the estimations made in Figure 14.

54 Air Navigation Services Division REPORT D-LFV (73) ADS-B coverage compared to SSR coverage The towers in Östgöta TMA rely on surveillance data from the Askersund MSSR and the SSR coverage in the TMA and control zones is quite good (see Figure 7) even though SSR coverage is not available all the way down to the airport surface. The ADS-B low-level coverage around the EGOA airports has been verified in the project to be reliable all the way down to the apron. Figure 20 and Figure 21 show a flight test at Norrköping airport with the flight inspection aircraft (CBN12) used by the LFV Group. The complete flight is shown in Figure 20 and the low level coverage for radar and ADS-B around Norrköping airport is plotted in Figure 21. The ADS-B information is available all the way down to the surface while radar has coverage down to about 300 ft. Latitude 58,7 58,68 58,66 58,64 58,62 58,6 58,58 58,56 58,54 58,52 16,1 16,2 16,3 16,4 16,5 16,6 16,7 16,8 16,9 17 Radar ADS-B Longitude Figure 20 Flight test by flight inspection aircraft (CBN 12) at Norrköping airport

55 Air Navigation Services Division REPORT D-LFV (73) ,1 16,15 16,2 16,25 16,3 16,35 16,4 16,45 16,5 Radar ADS-B Lo ng it ud e Figure 21 Altitude coverage for radar and ADS-B around Norrköping airport during flight test with flight inspection aircraft (CBN 12) Accuracy Measured at the airport surface, the accuracy for an ADS-B target with free skyward view towards the GPS satellites is good. An analysis based on reports from the ground station at Norrköping airport during one month (October 2005) showed that during the time of measurement no plot exceeded 6 meters from the nominal position, without differential GNSS corrections. If differential GNSS corrections had been available the accuracy would have been even better. As a reference the accuracy requirement for an Advanced Surface Movement Guidance and Control System (A-SMGCS) is 7.5 metres.

56 Air Navigation Services Division REPORT D-LFV (73) Figure 22. Plot pattern for ESSP Ground Station indicated in green, all plots within a 6 m radius. The vertical accuracy of ADS-B compared to SSR has been addressed as an issue since the altitude information in the EGOA aircraft is based on two altitude encoders units, one provide barometric altitude to the SSR transponder and the other to the ADS-B transceiver. This solution was chosen within the project to keep installation and certification costs down to minimum This is causing the SSR and ADS-B altitude reports to sometimes deviate, though a majority of the altitude reports are within ±100 ft from each other which is the resolution of the encoding used. See Figure 21. The recommendation for an operational system based on using barometric altitude is that the same altitude encoder is used to provide altitude to both the SSR transponder and ADS-B transceiver.

57 Air Navigation Services Division REPORT D-LFV (73) 8 DEMONSTRATIONS AND WORKSHOPS As part of the dissemination of the EGOA results, and in order to support the exchange of information with ANS organisations and the general aviation community, a series of EGOA demonstrations and/or workshops have been conducted. The first workshop was dedicated to ADS-B out. This event, which included live demonstrations, was held in Linköping, Sweden, in early September The second demonstration was held in Östgöta TMA in early April 2005 and presented live on-line at the annual EUROCONTROL Briefing for Business and General Aviation in Brussels. The third EGOA workshop was a joint event with the EUROCONTROL CASCADE programme an took place in late October The EGOA work on both ADS-B and FIS-B was presented. The target audience common for all workshops has been the European general aviation community and persons responsible for short-term as well as long-term development in ANS organisations and airports. 8.1 First EGOA Demo and Workshop As part of AVIGEN 2004, arranged by the Nordic Institute of Navigation in Linköping-Sweden, the EGOA project held several presentations and performed a successful live demonstration including ten ADS-B equipped aircraft on September 9, 2004, at Linköping university. At the same time an "open house" was held at Linköping Flying Club at Linköping-SAAB airport attracting many curious visitors. Figure 23 Some of the audience at Linköping University at the first EGOA demonstration.

58 Air Navigation Services Division REPORT D-LFV (73) The ADS-B equipped aircraft that participated were four PA28, one glider and five experimental aircraft, one ADS-B equipped airport vehicle also participated. The aircraft took off at about two o'clock pm from three different airports, Stockholm-Skavsta airport, Norrköping airport and Linköping-SAAB airport. Via an ADS-B server connected to the ADS-B ground stations the audience at AVIGEN 2004 as well as at the "open house" at Linköping-SAAB could follow the entire flights of all ten aircraft, all the way from take off to the landing at the airports about half an hour later. 8.2 Second EGOA Demo The second EGOA demonstration took place at EUROCONTROL in Brussels at the annual Briefing for Business and General Aviation in April 2005 and at the same time at a joint Swedish-Russian event at Malmö-Sturup airport in southern Sweden. Via an internet connection the audience in Brussels and Malmö could follow, in real-time, the flights that took place in Östgöta TMA in Sweden. Six aircraft and three vehicles participated. Both Multimode Radios and "ADS-B only" transceiver equipped aircraft participated. On-site in Brussels were Air Traffic Controllers from both Linköping-Malmen airport and Linköping-SAAB airport, to present the EGOA project and to answer questions from the audience. In Malmö LFV representatives was present to answer questions about the demonstration. 8.3 Third and Final EGOA Demo and Workshop Figure 24. Three of the 16 aircraft participating in the third EGOA demo The third and final EGOA demonstration and workshop was a joint event with the EUROCONTROL CASCADE programme where EGOA has provided data to their validation activities. More than 60 participants from all over Europe attended the workshop that was held at Norrköping airport and 16 ADS-B equipped general aviation aircraft participated in the demo flights.

59 Air Navigation Services Division REPORT D-LFV (73) ADS-B in and out were demonstrated together with the FIS-B MET REPORT service. The participants were offered come onboard and fly along with the aircraft during the demo flights. About 20 participants took the offer and got to see the ADS-B and FIS-B in action. The rest of the audience could follow the flights via displays on the ground. Figure 25: Audience at the third demo and workshop At the end of the day a panel debate was held with participants from the general aviation community, industry, LFV and EUROCONTROL.

60 Air Navigation Services Division REPORT D-LFV (73) 9 BUSINESS CASE FOR COMBINED VOICE & VDL MODE 4 RADIO As part of the EGOA project a business case [2] has been developed for a multimode radio (MMR) combining VHF Voice and VHF Data Link capability. An example of such a radio is the RTX6040 that has been used in the later half of the EGOA project. The business case has been developed by Helios Technology Ltd, UK, and the purpose of the business case is to show whether or not the multimode radio can generate enough benefits for the general aviation aircraft owner to motivate the investment of such a radio. In the section below you find the executive summary of the business case. The report in its whole can be downloaded from Business case executive summary In today s environment, the advantages of a harmonised approach to aviation are becoming increasingly apparent. European programmes such as SESAR (Single European Sky ATM Research) are attempting to embrace both the commercial and safety benefits of such an approach, but in many other cases the General Aviation (GA) and Aerial Work (AW) market is not considered in sufficient detail, if at all. General Aviation and Aerial Work have traditionally developed in a low regulation, low cost environment. This is under pressure from initiatives in the European economic, political and regulatory environment leading to higher costs, restricted access to airspace and airports, and an increased need for GA/AW to play their part in the safety of the overall system. Alongside the regulatory pressures on GA/AW, there are safety and efficiency improvements to be made. The issues highlighted by current GA/AW pilots are primarily related to a pilot s ability to obtain more detailed and accurate information, for example weather, surrounding traffic, airspace restrictions and so on. In addition, the tracking of GA/AW aircraft (by ATC, the GA/AW Operations Centre or Search and Rescue units) is problematic in many areas. Many of these issues could be solved through the equipage of an additional flight aid that enables pilots to readily access this information in the cockpit. A VHF- VDL Multi-Mode Radio (MMR) is one such flight aid that could fulfil this task, whilst preparing the GA/AW aircraft for potential future airspace regulations. In light of these issues, this business case has been developed to explore the potential benefits and costs of using a VHF/VDL multi-mode radio within General Aviation and Aerial work operations. The VHF/VDL radio (incorporating VDL4 datalink) can be used for voice and data communications such as broadcasting the aircraft s position and general flight information. In essence, this business case provides a product-focused, benefits-driven rationale for the market development in the main areas of GA/AW activity in Europe (UK, Germany and Sweden have been assessed). The study identified the need for a set of capability levels to be offered to the GA/AW market relating to varying functionality, applications and equipage

61 Air Navigation Services Division REPORT D-LFV (73) necessary. These ranged from the basic MMR (with an ADS-B out functionality only) to the high-end integrated CDTI solution. Having identified the capability levels, a qualitative and quantitative assessment of benefits and costs was carried out for several scenarios, including varying levels of regulatory impact. The benefits and costs were identified per aircraft, rather than per region, due to the lack of clear information on General Aviation for each country. Also, the scope of the study did not allow a full quantitative analysis to be carried out. Nevertheless, several conclusions can be drawn from this assessment: GA/AW users prepared to utilise the full functionality of the MMR (whether as a panel mounted PDA solution, or as an integrated CDTI) should expect to gain considerable benefits. In addition to clear safety benefits, there are some efficiency and cost-effectiveness gains to be made through increased knowledge of the surrounding environment. The situation for very small aircraft (gliders, microlights etc) is a little more complex. Equipping with the basic MMR solution would enable the user to mitigate any disbenefits arising from regulatory restrictions on sections of airspace, as well as benefiting from the added safety of being visible to ATC. The situation can be summarised as a straight cost trade-off between the MMR and the individual pieces of equipment likely to be required in the future (e.g. Mode S transponder). A break-even price for this comparison price for the MMR was calculated to be 4300 (taking into account discounted costs for future expenditure, and assuming that Mode S, GNSS and 8.33 khz radios need to be equipped at some point in the future). This is less than the currently anticipated market value of the MMR (which stands at around ). The value of the MMR for stakeholders other than the GA/AW flight crews should not be underestimated: Search and Rescue units, GA/AW Operations Centres, GA passengers, the general public, airlines, and Air Traffic Control units all stand to benefit from a general equipage of the Multi-Mode Radio.

62 Air Navigation Services Division REPORT D-LFV (73) 10 CONCLUSIONS 10.1 Achievement of project objectives To reconnect to the introduction of this document the project objectives are summarised in the bullets below and also to what extent the project has managed to fulfil the objectives: To evaluate and validate ADS-B and FIS-B for general aviation pilots. o As ADS-B is concerned this objective is considered to be fulfilled. The FIS-B functionality was introduced at the end of the project and will need further evaluation. To evaluate and validate ADS-B in a mixed radar and ADS-B environment from a controller perspective. o This objective is considered to be partly fulfilled. Partly, since the placing of the Air Traffic Controllers ADS-B/SSR Air Situational Displays had to be separated from the controller working position, due to safety considerations. As a result thereof, the amount of time for air traffic controller evaluation of the system became much smaller than the project had hoped for. However, the feedback received from the air traffic controllers involved has been very useable. To show potential benefits with ADS-B for Search and Rescue (SAR). o The verification of the low altitude coverage for this type of system shows that the ADS-B technology can be a cost efficient way to provide support in SAR operations. The Air Rescue Coordination Centre (ARCC) has been informed about the project development throughout the project and has shown great interest to make use of the system if it becomes operational. To spread knowledge about the issues addressed in the project and the proposed solutions to a wider audience within the aviation community. o This objective is also fulfilled. In addition to the pilots, air traffic controllers and technicians directly involved in the project, a wider audience has been reached in several ways. The EGOA project has been presented at ATM and general aviation workshops and meetings, both in Sweden and internationally. The EGOA website, has been a source of information about the ongoing activities and has had about 300 unique visitors each month since the launch of the webpage in October Finally the three demonstrations and workshops arranged have also attracted many participants from all over Europe. General aviation community representatives and ATM professionals involved in similar activities in Australia, Europe and USA have also been in contact

63 Air Navigation Services Division REPORT D-LFV (73) with the EGOA project via direct contact with the project management. To provide experiences and input to standardisation efforts for ADS-B and FIS-B. o Also fulfilled. Input from the EGOA project have been incorporated in both ETSI and EUROCAE documentation and project experiences are also being used in the joint EUROCAE and RTCA work on AIS and MET via To provide knowledge, experiences and an infrastructure, ground as well as airborne, to be used by future research and implementations projects addressing ADS-B, FIS-B or other data link applications. o Fulfilled already and probably even more so as time passes. EGOA experiences have already been used as input to the Kiruna ADS-B in Non-Radar Airspace implementation project and is also used in the joint EUROCONTROL and LFV project DAIM Digital Aeronautical Information Management Application specific conclusions Conclusions on ADS-B All aircraft or vehicles participating in the EGOA project have been equipped with a VDL Mode 4 transceiver, providing ADS-B reports to the ATC and to surrounding traffic, known as ADS-B out. Two different kind of transceivers from two different manufacturers have been used, one VDL-Mode-4-only transceiver, and one radio combining 8,33 MHz Voice and VDL Mode 4. In many of the aircraft participating in the project a Cockpit Display of Traffic Information (CDTI) has been used, allowing incoming ADS-B reports ( ADS-B in ) and FIS-B reports to be displayed. The CDTI hardware has been different models of Personal Digital Assistants (PDA) running a CDTI software developed within the project. The ADS-B equipment in terms of transceivers and displays, in aircraft as well as at the ATC, has not been allowed to use operationally. In the aircraft the system has been allowed to be installed and switched on but for evaluation purposes only, not to be used for navigation, conflict resolution or other decision-making. At the ATC the situation has been similar, the system has been allowed to install and to switch on but not in the vicinity of the controller s operational working position and for evaluation purposes only, not for surveillance purposes or decisionmaking. These limitations are all due to safety precautions, based on existing regulations and hazard analysis. Unfortunately the very same limitations have made the experiences gained within the project a bit hard to transfer to real operations, this should be kept in mind when reading the conclusions of this report.

64 Air Navigation Services Division REPORT D-LFV (73) The input from the pilots participating in the project has been a mix of positive feedback and of issues that needs further work before they can bring the expected benefits. Apart from the ADS-B out application, that operates autonomously and doesn t require any action or attention from the pilot, both of the other addressed applications, ADS-B in and FIS-B, are realised by interaction between pilot and the CDTI. The common view of the pilots is that being allowed to use the ADS-B application operationally will definitely enhance both safety and situational awareness. It is indicated, however not clear, that the head-down time will decrease compared to the paper chart environment that exists today and the use of old systems like NDB/ADF, ILS, VOR and DME. However it is considered that there is no doubt that the risk for navigation mistakes will be lower if the pilot is allowed to use the moving map feature of the CDTI and that the risk for incursion in the air or on the runway will decrease significantly when having other aircraft and airport vehicles displayed on the CDTI. An opinion received from almost all of the pilots that have used the CDTI is that the current solution with a PDA as the hardware platform running Windows Pocket PC as operating system and the CDTI software on top of that is not good enough for cockpit use. The display is considered to be to small, even for PDA models with a relatively large display, further on it is not considered to provide enough brightness nor contrast and also being too sensitive for reflections. The small size of the hardware has made it hard to interact with the PDA touch screen icons and/or firmware buttons using the fingers and the accompanying stylus cannot be used in a sometimes bumpy cockpit environment. Nor are the PDA devices hardware and operating system considered stable enough to be used for more critical applications. Conclusion is that the CDTI must be based on another hardware platform, more suitable for the cockpit environment. Regarding the ADS-B transceiver equipment itself there has been no negative impact on the airborne operations in terms of interference with other equipment or difficulties of operating the transceiver, on the contrary the transceiver is fulfilling the requirements for user friendliness, operating autonomously and not requiring the pilot to attend the system. The capability of providing many functions in one piece of equipment such as communication, surveillance and navigation is also considered valuable if allowed to be used operationally. The pilots who have used the multi mode radio type, housing both VHF voice radio and data link capability, consider this especially valid. The air traffic controllers at the participating ATC units are generally positive to the ADS-B application. The average air traffic controller is however not very interested in the technique behind the plot. The main issue for the air traffic controller is to make the aircraft visible on the air situational display in a safe and reliable way. If the aircraft is not visible, the controller has to block an entire sector only for one aircraft. If the aircraft is visible, the controller can separate directly to the actual position of the aircraft. Whether this is done via ADS-B, SSR or some other means is of less importance to the air traffic controller.

65 Air Navigation Services Division REPORT D-LFV (73) The combination of more aircraft getting equipped with transceivers (ADS-B or SSR), higher ADS-B update rate compared to SSR and the often superior ADS-B coverage can increase the situational awareness for the air traffic controller. However the mix of aircraft with SSR only, ADS-B only and SSR+ADS-B capability has raised a number of HMI issues concerning labelling, historical tail, double targets etc. Solutions to some of these issues are suggested in this report but it is obvious that this area requires more work. Whether the air traffic controller workload decreases, increases or remains at the same level as a result of the introduction of ADS-B has not been possible to verify since the ATC equipment has been running in shadow mode and not have been used operationally. The feedback from the air traffic controller regarding their first impression on ADS-B can be summarised as conservatively positive. It is the opinion from air traffic controllers perspective that the ones receiving the main benefits from the ADS-B and FIS-B applications that the EGOA project have been evaluating are the general aviation pilots and aircraft owners with ADS-B/VDL Mode 4 transceivers and CDTI equipped aircraft. It also the opinion that the introduction of ADS-B in an area as Östgöta TMA does not imply a significant difference for the air traffic controller compared to the current way of working. The EGOA project has verified that en-route coverage as well as low level and airport surface coverage can be achieved over a large area with ADS-B. The airport coverage also allows the ATC at one airport to see what is happening at a second airport if there are no ATC available at the second airport. This has been the case in EGOA under those hours where the Linköping-SAAB airport TWR has been open but the Linköping-Malmen airport TWR has been closed. All this can be achieved at a significantly lower infrastructure cost than with conventional SSR and surface movement radars (SMR). As the business case developed within the project indicates, these cost savings could be used by the air navigation service provider to finance incentives for the aircraft owners to equip with ADS-B equipment. The possibility for flying clubs and aircraft owners to use the ADS-B information in fleet management applications have been very appreciated and could be yet another mean to motivate the initial cost of aircraft equipage. Finally the use of ADS-B in search and rescue operations (SAR), as information source for last known position of missing aircraft but also for fleet management of SAR aircraft, has during the EGOA project created great interest at the Swedish Air Rescue Coordination Centre. ADS-B for SAR operations is something that should be investigated further Conclusions on FIS-B Common for the two FIS-B applications addressed in the project, MET REPORT and Temporary Segregated Areas, is that due to delays they were finalised in the very last stage of the project. Consequently the time for evaluation has not been sufficient.

66 Air Navigation Services Division REPORT D-LFV (73) The FIS-B MET REPORT application was available to the CDTI equipped aircraft in the project by September 2005 and has been technically verified. The pilots consider the MET REPORT, providing weather and runway information from a selected airport in text format on the CDTI, to be an important application that can increase the flight safety, compared to having a voice report delivered from the ATC on request from the pilot via voice. The reservation regarding the small size of the CDTI display mentioned in the conclusions on ADS-B above, making the information hard to see under certain conditions in the cockpit, is also valid for the MET REPORT application. From the air traffic controller s point of view the MET REPORT application as designed in EGOA would probably lead to a slight reduction of the workload. Calculations in the report shows that radio time spent on this kind of information could decrease 50% if the MET REPORT application was allowed to be used operationally by all aircraft. The summary of Safety Occurrence Reports in section indicates that general aviation aircraft are overrepresented in these reports when it comes to flights in controlled airspace without clearance. The FIS-B Temporary Segregated Area (TSA) application developed in the EGOA project, visualising the status and properties of the TSA graphically on a moving map display, could certainly decrease the number of this kind of incidents. Unfortunately this application was finalised in the very end of the project and has not been verified operationally, only technically. More in-flight evaluation of the MET REPORT application as well as the TSA application is needed to confirm the expectations on these applications Recommendations for further work It is recommended that the findings from EGOA be used in oncoming work in this area, being implementation projects, standardisation work, product development or research and development activities. It is recommended that further investigations be made concerning the use of ADS-B in search and rescue operations. This includes the placement of the coming ADS-B ground stations (to ensure coverage at low altitude). A special group should be formed with representatives from LFV and ARCC to investigate the issue. It is recommended that the impact of ADS-B and FIS-B use in general aviation aircraft in the operational work for the ATCO is investigated further (possibly by a simulation where the workload and situational awareness, for the ATCO, are studied). It is recommended that the development of new controller air situational display units (RDP/RPU) continues and is coordinated with other ADS-B projects. The same is also valid for the airborne side regarding cockpit displays (CDTI).

67 Air Navigation Services Division REPORT D-LFV (73) An introduction of ADS-B in military aircraft will most likely have a positive affect on the ATCO's work. The high-speed aircraft will get a shorter update rate on the air situational display and the situational awareness will probably get affected in a positive way as well. The workload for the ATCO's would probably be reduced if the military pilots got access to metreport via FIS-B. In the long term it should be possible for the military aircraft to make "in trail separation". This would most likely lead to reduce of workload as well. It's recommended that further investigations are made concerning ADS-B in military aircraft. It s recommended that further investigations are made concerning ADS-B in UAV and a special group should be formed with representatives from industry and LFV. It is recommended that the development of FIS-B services and on the standardisation thereof continues. The FIS-B services have been received with great interest but have not been investigated enough in the project. The business case also indicates that such services can be the driver for aircraft owners to invest in equipment that also gives benefits to the ANSP in terms of wide spread ADS-B equipage. It is recommended that a cost-benefit analysis for large-scale VDL mode 4 equipage of the Swedish general aviation aircraft fleet should be developed by LFV. This analysis should include possible incentives and/or financial solutions for the aircraft owner investment.

68 Air Navigation Services Division REPORT D-LFV (73) APPENDIX A What is ADS-B, FIS-B and VDL mode 4? This appendix is intended for readers who are not familiar with the concept of ADS-B/FIS-B/VDL Mode 4, other readers can skip this appendix. To explain, comparison can be made with an ordinary copper cable telephone line. The copper cable can be used to transport different content such as voice telephony or data communication. In the same way one can say that the data link, VDL mode 4, can be used to transport different content - different applications or services - such as communication services (FIS-B for instance), navigation services and surveillance services (ADS-B). Figure 26. VDL mode 4 as carrier for ADS-B and FIS-B applications Concept of ADS-B Automatic Dependent Surveillance Broadcast (ADS-B) is a surveillance application that via a broadcast mode data link transmits parameters such as fourdimensional position (x, y, z and time), track and ground speed, aircraft or vehicle identification and additional data as appropriate. ADS-B is automatic because it transmits automatically without any need for external stimulus- for example no action is needed form the pilot to transmit the position, nor is there a need for any request from the ground system to initiate transmission (as with current radars); it is dependent because it relies on on-board navigation sources and on-board broadcast transmission systems to provide surveillance information to other users. Any user, either aircraft or ground-based, within the range of this broadcast, may receive and process ADS-B surveillance information. The data to be transmitted is derived from on-board navigation and position-fixing systems, often, but not necessarily, Global Navigation Satellite Systems (GNSS) such as GPS,