GENERIC UAS ATM SAFETY ASSESSMENT BASELINE SCENARIO 2

GENERIC UAS ATM SAFETY ASSESSMENT BASELINE SCENARIO 2 UAS -VLOS [This generic UAS ATM Safety Assessment Baseline Scenario 2 for UAS applies only for systems that use command and control systems known as Visual Line Of Sight. This document does not constitute a concept of operations. The purpose of this document is to provide a framework which can be used to construct a generic safety case to facilitate the introduction of such operations in a consistent, coherent and safe manner into their airspace whilst offering continued safety to all existing users.] 3 rd October 2008 Version 1 1

GENERIC UAS ATM SAFETY ASSESSMENT BASELINE SCENARIO 2 UAS VLOS 1. Introduction 1.1. The purpose of this generic UAS ATM Safety Assessment Baseline Scenario 2 is to support the construction of a generic safety case for UAS 1 operations based upon Visual Line of Sight (see para 2 below) command and control systems in classes of European airspace where VFR flight is permitted. 1.2. The following assumptions have been used:- a) Airworthiness approval criteria are available and the UAS systems have been approved by the relevant approval authority, b) The target is for seamless integration of UAS operations into the current European ATM 2 system, c) The integration of UA should not make the airspace any less safe for existing users, d)only single UAVs are considered 3, e)tcas 4 will not be available for a UA but will be in operation with other airspace users, f) Only day VFR operations are considered, and g)uas operations comply with applicable ICAO standards 5 except where explicitly shown below. 2. UAS Mode Of Operation 2.1. The mode of operation considered for this document uses a command and control system (C2) known as Visual Line Of Sight (VLOS) 6. As the name implies the pilot keeps the Unmanned Aerial Vehicle (UAV) in direct visual observation for the duration of a flight or segment thereof and there is direct radio line of sight (RLOS) between the command and control position and the UAV at all times. 2.2. The pilot in command is positioned on the ground. 2.3. The primary mode of operation of a UAV should entail oversight by the pilot-incommand, who should at all times be able to intervene in the management of the flight. 3. Duration of the UAS operation 3.1. The duration of any operation is dictated by the demands of the task but can be expected range amounting from a few minutes up to the hours of available daylight. 1 UAS = Unmanned Aircraft System comprising a ground control station, an unmanned aircraft (UAV), the UAS crew and operational processes including flight crew procedures. 2 ATM = Air Traffic Management 3 The World Radio Conference of 2011 is expected to address the issue of spectrum allocation for UAS operations. Until then it is impossible to consider a situation where more than one UAV operates is close proximity to other UAVs controlled by their own dedicated ground control stations. 4 TCAS is the manufacturers trademark for ICAO Airborne Collision Avoidance Systems (ACAS) and software version 7 is the current version in use. 5 It has to be noted that ICAO in 2008 established an UAS Study Group, which will produce recommendations for specific provisions for UAS to be introduced in the ICAO Annexes. 6 The purpose of direct visual observation is safe control of the UA and the avoidance of collision with other airspace users, obstacles, terrain and weather. 3 rd October 2008 Version 1 2

4. Physical UAS Characteristics 4.1. The physical characteristics of the UAS used in VLOS operations, will vary considerably but will more usually be of small size and slow speed. This will limit the space available for equipment necessary for certain classes of airspace and makes the UAV difficult to be seen by pilots and other airspace users. 5. UAS Flight Performance 5.1. For the purposes of this document the UAS speed range is slow (less than 100kts IAS but could also be stationary) and the operating height is normally less than 2000 feet. 6. C2 Characteristics (e.g.: RLOS) 6.1. Direct radio line of sight is the method for command and control for VLOS flights. 7. Airspace Classifications 7.1. ICAO Airspace Classifications are contained in ICAO Annex 11 Air Traffic Services Chapter 2 para 2.6. Both controlled and uncontrolled airspace where VFR flights are permitted are considered. 8. Flight Rules 8.1. UAS VLOS operations shall comply with the general rules and with the Visual Flight Rules (VFR) as defined in Annex 2.The weather criteria for VFR flight is contained in ICAO Annex 2 (Rules of the Air) Chapter 3 para 3.9. The airspace classifications with their respective visibility and distance from cloud criteria are shown in Appendix B. 8.2. UAS operations are new and VLOS may not be able to comply with the existing criteria. It is envisaged, by the ICAO UAS SG, that Annex 2 will be revised to include specific references to UAS in this respect. It is important that vigilance in detecting potential collisions is maintained at all times. 8.3. Safe VFR operations depend on the pilot showing good airmanship at all times by doing nothing to endanger his aircraft and other airspace users. The rules of the air enable this to occur. However there are also best practice rules which also promote flight safety. These rules are generally known by pilots of manned aircraft. It is necessary for UAS pilots to have a complete understanding of all applicable rules and best practice techniques. 9. ATM UAS Operational Flight Planning 9.1. ICAO flight planning is an essential component for a safe flight whatever the circumstances. The pilot-in-command must assure himself that the intended flight is viable and can be carried out safely. ICAO Annex 6 Part 2 Chapter 4 says The pilot-in-command shall not commence a flight unless it has been ascertained by every reasonable means available that the ground and/or water areas and facilities available and directly required for such flight and for the safe operation of the aeroplane are adequate, including communication facilities and navigation aids. 3 rd October 2008 Version 1 3

Note. Reasonable means in this Standard is intended to denote the use, at the point of departure, of information available to the pilot-in-command either through official information published by the aeronautical information services or readily obtainable from other sources. 9.2. For the purposes of this document the term flight planning therefore only applies to those functions and responsibilities contained within ICAO Annex 6 and ICAO Doc 4444 PANS-ATM. It does not include any mission planning activity under the responsibility of an air operator 7, for such things as e.g. Minimum Equipment List (MEL), establishment of procedures, payload preparation, installation and recovery and so on. 9.3. It may not be necessary that a flight plan be filed with an ATS unit for VLOS operations except in airspace for which an ATC clearance is mandatory. 10. Segregated or not Segregated 10.1. The area of VLOS operations considered in this document is non-segregated airspace. 11. Populated areas 11.1. Aircraft, including UA, will fly over populated 8 areas and the operator is responsible for compliance with ICAO requirements that apply. 11.2.Overflying of people and property, (unless for the purpose of landing and departure) by manned aircraft is addressed by the standards in ICAO Annex 2 Chapter 4 para 4.6. which contains minimum height requirements applicable except when there is a different permission from the appropriate authority. 11.3. Both these requirements have to be properly assessed during the airworthiness certification process, for UA designed to fly at lower levels. 12. Communications 12.1. The requirements for UAS have to attain the same safety level than those for manned aircraft. Certain protocols and activities (including communications) may be required of the pilot which will be laid out in the permission granted for the flight. 12.2. VLOS operations will communicate to all relevant parties through appropriate means according to the airspace classification. 12.3. It must be noted that UA operations vary considerably from those of manned aircraft. Existing communication architecture may not be suitable in all circumstances. 13. Navigation 13.1. For UA operating by VLOS navigation is by visual observation which might be supplemented by other means. 13.2.The pilot must be able to navigate the UA to a safe and effective standard. 7 According to Regulation (EC) 08/2008 (so called EU-OPS ) the responsibility of an operator of an aeroplane used for commercial air transport, are separated from the responsibilities of the pilot (e.g. documents to be made available, in rule OPS 1.125). The same principle of clear distinction of responsibilities is being applied by EASA for the implementing rules following basic Regulation 216/2008. These principles will apply also to UAS. In case of the same person being the pilot, the owner and operator of an UAS; he/she will have to comply with both sets of rules. 8 The term populated has not been defined 3 rd October 2008 Version 1 4

14. Surveillance 14.1. Both cooperative and non-cooperative UAS are considered. ATC primary radar systems currently in use require a target of a specific radar cross section to be able to detect it. Small UAS will not be of sufficient size and therefore will not be detected by ATC. 14.2 In airspaces Classes E to G however, radar surveillance by ATC is not mandatory, since other means (e.g. voice position reports) of surveillance (or even no ATC surveillance) may be used. Additionally UAS may be equipped either with ATC Mode S transponder or ADS-B functionality. 15. See And Be Seen 15.1. The UAV pilot is responsible for the function of seeing and avoiding neighbouring air traffic, obstacles and terrain. 15.2. He must have sufficient situational awareness of the airspace and terrain surrounding his aircraft that he can identify a threat and then manoeuvre to avoid a conflict. 16. Pilot Qualifications 16.1. In general international standards for civil flight crew licensing are contained within ICAO Annex 1 9 Chapter 2 paras 2.3 and 2.4. 16.2. At the time of writing a class rating for UAS or other appropriate standards, has not been confirmed by ICAO. This document is based on Class ratings A and C. 16.3. Appendix 1 of the Annex gives the requirements for proficiency in languages used for voice communications. 16.4. Finally Annex 1 gives precise details of the flight instruction required to gain the qualifications set out therein, applicable to manned aircraft. 17. Weather 17.1. The UA pilot is responsible for the air vehicle remaining in VMC at all time. 17.2. The ability for the pilot to have a clear view around the UAV during its task is essential. The two factors that may be significant are the prevailing and future weather (including its implications 10 ) and any environmental activities that may interfere with a pilot s ability to safely fly his UA. 17.3. Forecast weather conditions can be received as part of the ATM flight planning process. However ICAO Meteorological Services 11 include the notification of significant weather events such as snow and fog warnings. A suitable method of alerting the relevant UAS personnel must be found and incorporated into the operational instructions 9 ICAO Annex 1 Personnel Licensing Version 10 July 2005 10 For example, a flight path that occurs in the lee of terrain may be subject to increased surface turbulence thereby making the UAV less stable in flight. Pilot awareness of this possibility and the need to take remedial action improves flight safety for other airspace users and for those on the ground. 11 ICAO Annex 3 Meteorological Services For International Air Navigation Version 16 July 2007 refers. 3 rd October 2008 Version 1 5

17.4. The UAV pilot must be able to assess changing atmospheric conditions in order to continue safe operations under all circumstances. 18 UAS Lighting Requirements and Signal Recognition 18.1. Only UAS operations by day are considered. 18.2. In general UAS will need to conform to ICAO requirements (ICAO Annex 2 refers). It may be necessary to define specific requirements for UAVs lighting. 18.3. ICAO Annex 2 also contains at Appendix 1 signals to and from a pilot. Where appropriate a UAS pilot must have sufficient visibility to ensure he can receive these signals. 19. Contingency & Emergency UAS Recovery Procedures 19.1. Flight Manual and operational approval contains within it the procedures for operating the UAS 19.2. When considering procedures for contingencies such as loss of command and control link it is essential to carefully consider the effect of such arrangements upon third parties whether airborne or on the ground. This aspect can be addressed during the pre-flight planning stage. 19.3. As far as practical a set of common contingency procedures to be used by all UAS operators should be agreed with ANSPs and airspace authorities. For example loss of control link and any associated recovery procedures may have significant impacts on ATC which will directly affect other airspace users. 20. Other Airspace Users 20.1. Other airspace users, whether hot air balloons, gliders, microlights or aircraft, comprise aircraft with a pilot onboard. All are subject to legally binding rules, in turn based on ICAO Annex 2 requirements and are able to respond to situations almost immediately 12. They are marked and lit according to applicable law and applicable certification specifications. Many of them voluntarily join an ATC service of some type and use radio to report position and to gain situational awareness traffic in the immediate vicinity, where those services are available. 21. Sense and Avoid 21.1. For the purposes of this document the term avoid applies equally to other airspace users, weather, obstacles and terrain. It does not address avoidance of traffic manoeuvring on the surface of an aerodrome. 21.2. In the ICAO guidance Doc 9854 Conflict Management is broken down into 3 activities namely:- 12 Pilot reaction times may significantly vary, depending on the type of licence. In addition the timeliness of any action, is also related to the speed of the involved aircraft. 3 rd October 2008 Version 1 6

i) Strategic Conflict Management, ii) Separation 13 Provision, and iii) Collision Avoidance (see para 22 below) 21.3. In ICAO airspace Classes A, B and C separation is provided by ATC, in Class D ATC provided separation between IFR traffic and between IFR and VFR when requested by the pilot, and finally in Classes E, F and G airspace, VFR flights are required to self-separate against any traffic that might be in conflict with it. Separation minima is defined for Classes A, B,C and D ( between IFR traffic) but not for all other airspace classes and the pilot is required to show good airmanship and good judgement in applying a safe separation distance from conflicting traffic. Therefore, also for UAS VLOS operations in airspace Classes E, F and G requirements for separation minima do not exist, while the pilot, like any other pilot under VFR, is required to self-separate his/her aircraft from any other traffic, in order to avoid conflict. 22. Collision Avoidance Function 22.1. Collision avoidance becomes necessary when separation provision fails and is a requirement for all aircraft, all classes of airspace, all weather conditions and for all flight rules. 22.2. Collision avoidance is always the pilot s responsibility regardless of the airspace within which he is operating. 22.3. The Collision Avoidance Function is applied when traffic conditions or proximity of raising terrain and/or obstacles are such that application of visual separation assurance principles/techniques cannot be applied in a timely, managed and safe manner. As such, the point in time at which the Collision Avoidance Function is initiated can be independent of considerations with respect to whatever separation assurance being applied by the pilot at the time the function starts. 22.4. Collision avoidance takes place using a conflict horizon potentially smaller than that used for separation provision. Therefore when it becomes necessary the manoeuvres can be more urgent than for separation assurance. 22.5. Equally, terrain avoidance is the UAV pilot s responsibility. 22.6. Pre-flight planning is used to identify any terrain issues that a pilot needs to alert to before becoming airborne so that safe avoidance strategies can be formulated in a timely manner. 22.7. It is necessary for the pilot to be aware when terrain is present in real time and to be able to control the UAV sufficiently well to ensure collision avoidance. Additionally the situational awareness of the pilot must be kept at an appropriately high level. 22.8. Also the pilot is equally responsible for separation assurance during VLOS operations. 13 Separation, where prescribed, is either vertical (1000ft normally) or horizontally (various distances expressed in nautical miles and dependent upon technical characteristics but typically 3, 5 or 10nm). Good airmanship in this context may be translated to be close enough to be seen by another aircraft but not so close as to frighten the pilot of that aircraft. 3 rd October 2008 Version 1 7

23. Air Traffic Management 23.1. The UAS pilot is responsible for compliance with the applicable ATM requirements applicable in the airspace where the flight takes place. 24. Interoperability / Transfer of Control / Cross-border Operations 24.1. Not applicable for this scenario. 25. Security(Datalink) 25.1. Security of the UAS command, control and communications link will be ensured. 26. Payload 26.1. Payload is considered external to the UAS system from an ATM perspective and is therefore not considered. 3 rd October 2008 Version 1 8

Appendix A ICAO Guiding Principles 14 For ATM 1. Introduction. 1.1. The ATM system is based on the provision of services. This service-based framework considers all resources, inter alia, airspace, aerodromes, aircraft and humans, to be part of the ATM system. The primary functions of the ATM system will enable flight from/to an aerodrome into airspace, safely separated from hazards, within capacity limits, making optimum use of all system resources. The description of the concept components is based on realistic expectations of human capabilities and the ATM infrastructure at any particular time in the evolution to the ATM system described by this operational concept and is independent of reference to any specific technology. Based on these considerations the elements are predicated on the guiding principles that follow. 2. Drivers For Change 2.1. The ATM environment, like so many other environments today, is driven by safety and Increasingly, by commercial or personal outcome expectations. There are standards in place for global interoperability, and many States systems have evolved within a standards framework to levels that are able to sustain their individual requirements. However, they now struggle or fail to meet the ever-growing user expectations of global harmonization and interoperability. 2.2. In 2000, a range of factors, including cost, efficiency, safety and national interest, drove change in the ATM system. Now, however, the driver for change must be ATM user expectations, within a framework of safety and business cases, and cost/benefit analysis. The operational concept identifies a range of user expectations; however, it is recognized that within the planning horizon, the set of solutions to provide expected benefits may change, and this will be identified and implemented through the safety and business case process. 3. Guiding Principles 3.1. Safety. The attainment of a safe system is the highest priority in air traffic management, and a comprehensive process for safety management is implemented that enables the ATM community to achieve efficient and effective outcomes. 3.2. Humans. Humans will play an essential and, where necessary, central role in the global ATM system. Humans are responsible for managing the system, monitoring its performance and intervening, when necessary, to ensure the desired system outcome. Due consideration to human factors must be given in all aspects of the system. 3.3. Technology. The ATM operational concept addresses the functions needed for ATM without reference to any specific technology and is open to new technology. Surveillance, navigation and communications systems, and advanced information management technology are used to functionally combine the ground-based and airborne system elements into a fully integrated, interoperable and robust ATM system. This allows flexibility across regions, homogeneous areas or major traffic flows to meet the requirements of the concept. 3.4. Information. The ATM community will depend extensively on the provision of timely, relevant, accurate, accredited and quality-assured information to collaborate and make informed decisions. Sharing information on a system-wide basis will allow the ATM community to conduct its business and operations in a safe and efficient manner. 3.5. Collaboration. The ATM system is characterized by strategic and tactical collaboration in which the appropriate members of the ATM community participate in the definition of the types and levels of service. Equally important, the ATM community collaborates to maximize system efficiency by sharing information, leading to dynamic and flexible decision making. 14 Source : ICAO Doc 9854 Global Air Traffic Management Operational Concept Version1 2005 3 rd October 2008 Version 1 9

3.6. Continuity. The realization of the concept requires contingency measures to provide maximum continuity of service in the face of major outages, natural disasters, civil unrest, security threats or other unusual circumstances. 4. Future ATM System 4.1.The ATM community s expectations should guide the development of the future ATM system. The ATM operational concept will guide the implementation of specific ATM technology solutions. It is crucial that the evolution to the global ATM system be driven by the need to meet the expectations of the ATM community and enabled by the appropriate technologies. 3 rd October 2008 Version 1 10

APPENDIX B ICAO AIRSPACE CLASSIFICATIONS The airspace classifications with their respective visibility and distance from cloud criteria are shown in the table below: Altitude band Airspace class Flight visibility Distance from cloud At and above 3 050 m (10 000 ft) AMSL Below 3 050 m (10 000 ft)amsl and above 900 m (3 000 ft) AMSL, or above 300 m (1 000 ft) above terrain, whichever is the higher A*** B C D E F G 8 km 1 500 m horizontally 300 m (1 000 ft) vertically A***B C D E F G 5 km 1 500 m horizontally 300 m (1 000 ft) vertically At and below 900 m (3 000 ft) AMSL, or 300 m (1 000 ft) above terrain, whichever is the higher A***B C D E --------------------------------- F G 5 km --------------------------- 5 km** 1 500 m horizontally 300 m (1 000 ft) vertically ------------------------- Clear of cloud and with the surface in sight Notes * When the height of the transition altitude is lower than 3 050 m (10 000 ft) AMSL, FL 100 should be used in lieu of 10 000 ft. ** When so prescribed by the appropriate ATS authority: a) flight visibilities reduced to not less than 1 500 m may be permitted for flights operating: 1) at speeds that, in the prevailing visibility, will give adequate opportunity to observe other traffic or low volume traffic and for aerial work at low levels. 2) in circumstances in which the probability of encounters with other traffic would normally be low, e.g. in areas of low volume traffic and for aerial work at low levels b) HELICOPTERS may be permitted to operate in less than 1 500 m flight visibility, if manoeuvred at a speed that will give adequate opportunity to observe other traffic or any obstacles in time to avoid collision. ***The VMC minima in Class A airspace are included for guidance to pilots and do not imply acceptance of VFR flights in Class A airspace. Fig 1 ICAO Airspace Classifications Flight Visibility and Distance From Cloud Criteria. 3 rd October 2008 Version 1 11

APPENDIX C SEE AND AVOID 1.1. ICAO Circular 213 (dated 1989) 15 says The practice of "see-and-avoid" is recognized as the primary method that a pilot uses to minimize the risk of collision when flying as an uncontrolled flight in visual meteorological conditions. "See-and-avoid" is directly linked with a pilot's skill at looking about outside the cockpit or flight deck and becoming aware of the surrounding visual environment. Its effectiveness can be greatly improved if the pilot can acquire skills to compensate for the limitations of the human eye. These skills include the application of effective visual scanning, the ability to listen selectively to radio transmissions from ground stations and other aircraft to create a mental picture of the traffic situation, and the development of habit patterns that can be described as "good airmanship" 1.2. The circular also considers those factors that contribute to collisions and concludes that traffic congestion and aircraft speeds are part of the problem 16. Therefore careful consideration of closure rates between UA and other airspace users will assist industry greatly in fixing performance figures for airworthiness certification. 1.3 These factors are all contributory causes, but the reason most often noted in the mid-air collision statistics reads "failure of pilot to see other aircraft" - in other words, failure of the see-and-avoid system. In most cases at least one of the pilots involved could have seen the other in time to avoid the collision if that pilot had been watching properly. Therefore, it could be said that it is really the eye which is the leading contributor to mid-air collisions. 1.4. All the above applies to UAS operations that are subject to this document. There are two issues that require addressing. Firstly the UAV must be seen by other airspace users and visual acquisition must be early enough for threat identification, deciding the most appropriate manoeuvre and then carrying it out. Manned aircraft are fitted with navigation and anti-collision lights and are generally painted in colours that enable early recognition by other users. This requirement is one for UAVs also. ---------------- 15 The text underlined is quoted directly from the ICAO circular 16 In the head-on situation, for instance, a jet and a light twin-engine aircraft may have a closing speed of about 1 200 km/h (650 kt). It takes a minimum of 10 seconds for a pilot to spot traffic, identify it, realize it is a collision threat, react, and have the aircraft respond. But two aircraft converging at 1 200 km/h (650 kt) will be less than 10 seconds apart when the pilots are first able to see each other! The actual values quoted here may not apply to UAS covered by this document but are included to be indicative. 3 rd October 2008 Version 1 12