Interactions Between Unmanned Aircraft Systems Operators and Air Traffic Control

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Interactions Between Unmanned Aircraft Systems Operators and Air Traffic Control

59TH ANNUAL CONFERENCE, Singapore, 30 March – 3 April 2020

WP No. 89

Interactions Between Unmanned Aircraft Systems Operators and Air Traffic Control

Presented by TOC

 

IMPORTANT NOTE: The IFATCA Annual Conference 2020 in Singapore was cancelled. The present working paper was never discussed at Conference by the committee(s). Resolutions presented by this working paper (if any) were never voted.

Summary

With the increasing popularity and increase in UAS incidents, we need to come up with a solution to both keeping UAS from entering controlled airspace and adapt to having some drone traffic operating in or close to controlled airspace. We need to determine if current rules allow for separation between drone traffic and regular traffic, and separation between UAS.

Introduction

1.1.  In recent years, IFATCA has produced several working papers about Unmanned Aircraft Systems (UAS). These papers resulted in several policy statements that have been consolidated into one section of IFATCA’s Technical and Professional Manual (TPM). Due to the quickly evolving landscape and utilisation of UAS, it was deemed necessary to perform a review of the current policies and provide updates to the existing material.

1.2.  There is sometimes confusion on the terminology relating to unmanned aircraft and remote piloted aircraft i.e. difference between RPAS and UAS.

1.3.  UAS are being bought and flown in record numbers, data shows that by December 31, 2018 there were 900,000 UAS registered in the U.S. and it was estimated that there was actually about 1.25 million (https://www.faa.gov/data_research/aviation/aerospace_forecasts/media/unmanned_aircraft_systems.pdf pg.41-42). With projected annual growth of 13% by 2020 there will be almost 1.5 million UAS.

1.4.  More commercial operators are looking at implementing UAS in their everyday operations. For example, Amazon has ambitious plans to operate a fleet of delivery UAS, offering 30-minute delivery to certain areas. Their first demonstration of the service was Dec 7, 2016 in England.

1.5.  Most countries have implemented new rules regarding UAS, usually dealing with segregation of UAS and Conventional Piloted Aircraft (CPA), however as numbers of UAS incidents with CPA are increasing, more needs to be done.

1.6.  With larger autonomous UAS coming into service, situations will start to arise where these UAS may want to enter controlled airspace and current rules and regulations may not be fit for purpose. The UAS in question may be required to be outfitted with aviation grade navigation and communication capabilities. If UAS were to equip with aviation transponders, issues may also arise with frequency spectrum congestion on the 1090 MHz and 978 MHz bands (Review of Radio Frequency Spectrum Protection Policy, WP 88, IFATCA 58th Annual Conference 2019, Conchal, Costa Rica).

Discussion

2.1  Different terms are in use when it comes to unmanned aerial vehicles. The most popular and well-known of these is ‘drone’. However, this term strictly speaking refers to unmanned aircraft used in a military context.

2.1.1  Remotely Piloted Aircraft Systems (RPAS) is the term currently in used the most in international bodies and environments. RPAS are subject to the same equipage and certification requirements for manned aircraft operating in the airspace.

2.1.2  Unmanned Aircraft Systems (UAS) is the overarching term for all types of airborne systems that are unmanned. UAS can vary wildly in shape, size and performance (Fact Sheet Unmanned Aircraft Systems, FAA, March 2015). RPAS is the commonly used term in IFATCA but it does not cover the entirety of the spectrum of unmanned aircraft. The term UAS covers all unmanned aircraft and is in wide use in North America and the United Kingdom as well as European Union legislation.

2.1.3  According to skybrary.aero and in DOC 10019 the Manual on Remotely Piloted Aircraft Systems the definitions of the two terms are as follows:

Unmanned Aircraft Systems (UAS): an unmanned aircraft and the equipment to control it remotely.

(https://www.skybrary.aero/index.php/Unmanned_Aerial_Systems_(UAS), last edited on 8th of September 2019.)

Autonomous UAS are UAS that can operate without any human intervention. In other words, it can take off, carry out missions, and land completely autonomously.

Doc 10019:

Remotely piloted aircraft system (RPAS). A remotely piloted aircraft, its associated remote pilot station(s), the required command and control links and any other components as specified in the type design.

ICAO DOC 10019 Manual on Remotely Piloted Aircraft Systems, First Edition, Montréal 2015

2.1.4  These definitions differ only on one point and that is that UAS might be controlled in other ways than directly by a remote pilot.

2.1.5  DOC 10019 also mentions the following:

This manual addresses RPAS as one subset of UAS. RPAS are envisioned to be an equal partner in the civil aviation system, able to interact with air traffic control (ATC) and other aircraft on a real-time basis. The scope of ICAO provisions in the next 5 to 10 years is to facilitate integration of RPAS operating in accordance with instrument flight rules (IFR) in controlled airspace and at controlled aerodromes. While not excluding visual line-of-sight operations from consideration, these are viewed to be a lower priority for global harmonization of international flights.

ICAO DOC 10019 Manual on Remotely Piloted Aircraft Systems, First Edition, Montréal 2015

ICAO appears to adopt a narrower view of RPAS here than the definition in the document would suggest. One interpretation is that we should only consider UAS that wish to integrate into the civil aviation system as RPAS. The EU on the other hand does not mention the term RPAS once in its regulations 2019/945 and 2019/947 pertaining to UAS. At the time of writing there is no consensus on this issue and therefore IFATCA will include the definitions listed under 2.1.3 in the Technical and Professional Manual in the Definitions section as both terms are in use.

2.2  EU regulations 2019/945 and 2019/947 set out rules and procedures for drone manufacturers and drone pilots respectively. They constitute the most comprehensive effort so far by lawmakers to regulate the operations of UAS and their integration into the legal and aviation systems.

2.2.1  Currently most countries have implemented new rules regarding operation of UAS and keeping them segregated from CPA. One example for instance is allowing them to operate at maximum 400ft AGL and outside 3 NM of airports and outside 1 NM of heliports. However, with some autonomous UAS there may be a desire to fly in controlled airspace, and these rules do not cover all situations where UAS and aircraft may be using the same airspace.

2.3  If UAS are to enter controlled airspace as it currently exists, or if CPA are going to be sharing airspace with UAS, it must be ensured that these UAS can operate safely and without inhibiting CPA in their regular operations. Current rules do not provide an adequate framework for this concept of operations in most places.

2.4  ICAO’s ATMOPS panel has devised a rough classification of UAS in three categories:

1) Large UAS that can comply with existing ICAO regulations regarding equipage. Navigational and communication equipment are on board and they participate in the ATM system as any other CPA would. This is the class of UAS that is adequately covered by existing IFATCA policy.

2) Smaller commercially operated UAS. They cannot comply with existing regulations but can be trusted to conduct themselves according to a given ruleset. These might also be operated by the more knowledgeable enthusiast. These kinds of operations are likely to take place with some sort of authorization by the ANSP, whether through UTM or other means. And whether that be tactical on a case-by-case basis or more generally with corridors or “drone zones”. It is not out of the question that the preferable solution is that these operations are kept outside the controller’s situational awareness for screen clutter or workload related issues.

3) Smaller UAS operated by malicious actors or members of the public lacking sufficient knowledge to assess the impact of their toy properly. Procedures to mitigate the hazards for commercial traffic and handholds for controllers to be able to act in these inevitable occurrences.

2.5  In order to keep controllers involved when it comes to the administration and regulation of the airspace in which they work, it is necessary for IFATCA to continually review and develop policy according to the evolving realities in aviation to provide controllers with as much guidance as possible. At the end of the discussion section current IFATCA policy is reviewed.

2.6  UAS navigational capabilities need to be assessed to ensure that they meet the requirements for the airspace they will be flown in.

2.7  If UAS were equipped with a mode-C transponder or a low power ADS-B squitter, it would aid air crews in being able to spot or at least detect the UAS via electronic means (TCAS) and enable ATC to track the UAS. However, this may cause a nuisance when it comes to scope clutter on flight decks as well as Controller Working Positions (CWP) (Display of Unmanned Aerial System (UAS) surveillance data on Controller working position, WP 90, IFATCA 57th Annual Conference 2018, Accra, Ghana). This also brings up an issue with frequency congestion, as there have already been reports of 1090 MHz bandwidth congestion at busier airports.

2.8  IFATCA’s Professional and Legal Committee (PLC) drafts a paper concerning Unmanned Traffic Management (UTM). This paper is slated for discussion at IFATCA’s 59th Annual Conference in Singapore in March alongside this document. Elements of a UTM system have been and are being rolled out in a number of places and may provide handholds for ATC professionals to more safely integrate UAS operations in their work.

2.9  Starting in 2020, all UAS in Europe will be required to carry on board locator devices. These will transmit a unique ID and the device’s location continuously via the mobile telecommunications network. While this is not ready for immediate integration into most current ATM systems it will allow for more comprehensive trackability and traceability in case of airspace infringements. A UTM system might be able to use this location information for geofencing, notifications or alerting services as well as conflict detection with CPA.

2.10  UA pilots currently are required to maintain visual line of sight (VLOS), however most UAS can provide telemetry data to the control base station and some even provide live video. This allows these aircraft to operate beyond visual line of sight (BVLOS). Unfortunately, BVLOS operations have led to incidents where UAS have either inadvertently or intentionally operated in controlled airspace and caused over 1800 sightings of UAS by aircrew in the US (2016). An aircraft moving at 160kts on approach only has about 8 seconds to respond to the drone, however according to the FAA (FAA Advisory Circular 90-48D, https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_90-48D.pdf, 19th of April 2016) the average pilot requires 12.5 seconds to see an obstacle, recognize it, be aware of the collision course and make the necessary avoidance maneuver.

2.11  With current practice of see and avoid, UAS will be required to be able to sense other aircraft and UAS and take appropriate action to avoid collision. This may not be possible for all classes of drone. Especially the smaller toy UAS are unlikely ever to be equipped with technology of that kind.

2.12  It seems that it is becoming impossible to not allow unmanned aircraft to integrate into the civil aviation airspace. At the same time, air traffic controllers are always very aware of the potential hazards that such a change might introduce. Designated areas for UAS to conduct operations within areas like CTRs, like corridors or low level “drone zones”, might allow ANSPs to accommodate these operations. Of course, these areas would function to safeguard the approach and final approach areas, as well as the physical maneuvering area of the aerodrome and the climb out areas. Controllers should be central to, and included in, any planning, design or creation of areas to facilitate the inclusion of UAS in controlled airspace.

2.13  There are currently a lot of simultaneous initiatives active which seek to regulate UAS flights as well as assess the risks and accommodate airspace users. JARUS is one such initiative in which some large players in aviation are involved. In the USA, LAANC has been implemented which allows UAS operators to submit a flight proposal for automated review and approval (or rejection) by the relevant ANSP.

2.14  One of the most complex questions when it comes to the operations of UAS in or near controlled airspace is the question of what separation standard to apply. In some low-level controlled environments ANSPs are implementing a concept of integrated and segregated areas. In the segregated areas, UAS can operate at will, with the understanding that they must remain clear of the integrated areas. Should they wish to enter the integrated area they need approval from ATC as normal. This allows UAS operators more freedom while at the same time safeguarding CPA.

2.15  Drone operators should be properly rated according to local and/or national rules and regulations to operate in controlled airspace and should have an acceptable means for immediate communication (VHF, mobile phone/satellite phone) for direct contact with ATCOs or a delegated coordinator for the ANSP.


2.16 Review of policy

In this section the policy listed in the IFATCA Technical & Professional Manual (TPM) under section AAS 1.10 is reviewed step-by-step:

2.16.1

IFATCA is opposed to the operations of any autonomous aircraft in non-segregated airspace.

 

This section of the policy remains fully correct. The definition of autonomous operations means that these aircraft will not be controlled remotely by either an operator or be able to receive instructions from ATS units. This makes their operation incompatible with the definition of controlled, non-segregated airspace. This section of the policy should remain in the TPM unamended.

2.16.2

All Remotely Piloted Aircraft Systems (RPAS) operations in non-segregated airspace must be in full compliance with ICAO regulations.

 

It is questionable if this position is realistic. It means that devices with vastly different performance profiles, navigational and communications capabilities must all be in two-way radio contact in controlled airspace, where controllers are then expected to maintain the same separation standards as between conventional aircraft. This concept is only properly applicable with the same sort of performance profile, navigational, communications and surveillance capabilities of all other aircraft operating in the airspace.

ICAO regulations do not exist specifically for RPAS. Several efforts are underway to fill this procedural ‘vacuum’ by different initiatives. The Joint Authorities for Rulemaking on Unmanned Systems (JARUS) is one such initiative. JARUS is a collection of CAAs and other agencies sharing experience and knowledge in order to create a greater understanding of RPAS operations and needs as well as requirements for their safe deployment. IFATCA has been monitoring developments in this group and while there are good developments there have also been some issues in JARUS’ approach to drone operations within controlled airspace. It is therefore imperative that IFATCA carefully considers its position in this complex playing field.

If local authorities, using an established Safety Management System (SMS) and with sufficient input from operational controllers, design procedures that allow for safe UAS operations within controlled airspace, IFATCA sees no grounds to oppose accommodating these new users of controlled airspace. Of course, this is a delicate balance to strike, because IFATCA must keep controllers’ interests at heart at all time. High standards from regulators must be expected and critical questions should be asked about how things will remain manageable, both in terms of complexity and workload, as well as safety.

It is proposed that the policy statement listed under 2.16.2. be replaced with the following:

All Unmanned Aerial Systems (UAS) operations in non-segregated airspace must be in full compliance with established ICAO and/or national and/or local regulations.

This section will subsequently be moved to a different place in the policy statement. This will become clear in section 4 under the Draft Recommendations.

2.16.3

Whether the pilot is onboard or not shall be irrelevant for the purposes of air traffic control, therefore the same division of responsibilities and liabilities as manned aircraft shall apply.

 

With the growing number of UA operations and the increasing demand for them, it is expected that traffic numbers for this kind of operation will soon exceed CPA movements. If that is the case, these operations and the requirements placed on them by this policy would cause undue workload to controllers and undue restrictions to the burgeoning RPAS sector.

From the classification listed under paragraph 2.3 of this document we may derive policy that is more fit for purpose. When it comes to the larger UAS which are properly equipped, an ability to adhere to current ICAO regulations should be expected. In this case, the above policy is valid and a reasonable position to take.

For the smaller classes of drones, it is not realistic to expect the same division of responsibilities and liabilities as they will not in all cases have the equipment, training or capability to do such. Different solutions such as segregated areas for UA would be a more practical proposition.

In conclusion, the policy can remain as it is, but requires the addition of the risk-based procedures section under 2.16.5.

2.16.4

ATCOs shall not be held liable for incidents or accidents resulting from the operations of RPAS that are not in compliance with ICAO requirements, in non-segregated airspace.

 

While this section of the policy is worthwhile because of its protective attitude to ATCOs, it is already a reality that local authorities are devising their own regulations due to the lack of ICAO SARPs. The policy therefore will not cover all situations an ATCO might find themselves in. A rewording of this policy is proposed to reflect the developing situation and clarify that there may be situations where rules have been prescribed by the local CAA. It is also proposed that RPAS is replaced with UAS in this particular section, as it covers all instances of unmanned aircraft.

Replacement proposal:

ATCOs shall not be held liable for incidents or accidents resulting from the operations of UAS that are not in compliance with ICAO and/or national and/or local regulations, in non-segregated airspace.

2.16.5 As was raised at ICAO’s 40th Triennial Assembly in Montreal this year, there is a growing concern amongst pilots as well as controllers about unauthorized drones operating near aircraft in critical phases of flight at very low level near aerodromes (IFALPA Press Release “Global Pilots & Industry Partners call for New Guidance on Drone Operations” dated 10th of October 2019, Montreal). Incidents like those at London Gatwick illustrate that the danger of these type of occurrences is real and the economic impact and potential safety impacts are tremendous. IFATCA recognizes the need for better guidance for controllers and pilots.

Therefore, it is proposed to add a new policy statement to AAS 1.10:

IFATCA recommends the development of risk-based procedures for UAS operations whether or not UAS operations be approved.

With this policy statement IFATCA states its desire to provide controllers and other aviation professionals the guidance they need to safely operate in an airspace where UAS operations are a reality. This policy statement will be in addition to the policy which is already in place. A re-ordering of the policy is proposed for clarity reasons.

2.16.6 The rest of the current policy remains valid and should therefore remain in place. The only change in content that is proposed is to change RPAS to UAS, to maintain internal consistency. As mentioned before it is also proposed to change the ordering of the statements.

The current order of the rest of the policy is as follows:

Standardized procedures, training and guidance material shall be provided before integrating RPAS into the Civil Aviation System.

IFATCA encourages education and awareness campaigns on the use of RPAS for the general public.

IFATCA urges the development and implementation of technology to prevent airspace infringements by Unmanned Aircraft.

Contingency procedures and controller training shall be provided for the management of infringements by Unmanned Aircraft.

 

It is proposed to re-order the policy and change RPAS to UAS:

Standardized procedures, training and guidance material shall be provided before integrating UAS into the Civil Aviation System.

IFATCA recommends the development of risk-based procedures for UAS operations whether or not UAS operations be approved.

Contingency procedures and controller training shall be provided for the management of infringements by Unmanned Aircraft.

IFATCA urges the development and implementation of technology to prevent airspace infringements by Unmanned Aircraft.

IFATCA encourages education and awareness campaigns on the use of UAS for the general public.

In this way, all policy statements pertaining to procedures are grouped which makes for clearer reading.

Conclusions

3.1  Rather than thinking of all unmanned aircraft as one and the same, it is important to consider the multitude of different kinds that exist. Unmanned aircraft can have vastly different performance profiles, as well as large variations in communications, navigational and surveillance capabilities. There is no one size fits all approach to regulation when it comes to UAS. ICAO’s ATM Ops Panel has devised a rough classification of drones which is very useful for categorising and solution orientation.

3.2  The landscape of aviation is changing quickly and sometimes outside the ATC sphere of influence. Rather than reflexively opposing these innovations out of a safety motivated perspective, IFATCA must attempt to remain influential. If controllers want some control over the implementation of new concepts and procedures for UAS then IFATCA must take a collaborative approach.

3.3  Firm requirements are necessary to safeguard CPA operations, but there are modes available in which both sectors can co-exist and operate side-by-side. LAANC and various other configurations like ATZs or segregated areas are already evidence of this. These configurations leave the ATM system in charge of what is possible and what is not and is the current preferred concept of operations. Controllers should be central to, and included in, any planning, design or creation of areas to facilitate the inclusion of UAS in controlled airspace.

3.4  Full integration does not seem possible yet, especially when it comes to the smaller, less advanced classes of unmanned aircraft, but the future may bring tools such as UTM which may allow controllers more influence in UA flight profiles.

3.5  A policy review was conducted to update IFATCA’s position for the developments in unmanned aviation.

3.6  A variety of tools and workarounds are starting to be available to accommodate UAS operations in or near controlled airspace and could provide handholds for ATCOs and CAAs alike to mitigate the safety risks of UAS operations. Further development of these tools and procedures appears to be the best way forward to achieve that goal. IFATCA has produced work on this before which remains valid.

3.7  Special care must be taken to ensure that the high pressure from UAS operators and local regulators does not result in a situation that is unsafe for CPA.

3.8  ATC’s foremost priority must always be the safety of conventionally piloted aircraft but IFATCA acknowledges that collaboration and development of new procedures and standards are necessary to ensure that UAS integrate safely into the aviation landscape.

Recommendations

4.1 It is recommended that IFATCA policy AAS 1.10:

IFATCA is opposed to the operations of any autonomous aircraft in non-segregated airspace.

All Remotely Piloted Aircraft Systems (RPAS) operations in non- segregated airspace must be in full compliance with ICAO requirements.

Whether the pilot is onboard or not shall be irrelevant for the purposes of air traffic control, therefore the same division of responsibilities and liabilities as manned aircraft shall apply.

ATCOs shall not be held liable for incidents or accidents resulting from the operations of RPAS that are not in compliance with ICAO requirements, in non-segregated airspace.

Standardized procedures, training and guidance material shall be provided before integrating RPAS into the Civil Aviation System.

IFATCA encourages education and awareness campaigns on the use of RPAS for the general public.

IFATCA urges the development and implementation of technology to prevent airspace infringements by Unmanned Aircraft.

Contingency procedures and controller training shall be provided for the management of infringements by Unmanned Aircraft

Is amended to read:

IFATCA is opposed to the operations of any autonomous aircraft in non- segregated airspace.

All UAS operations in non-segregated airspace must be in full compliance with ICAO and/or national and/or local regulations.

Whether the pilot is onboard or not shall be irrelevant for the purposes of air traffic control, therefore the same division of responsibilities and liabilities as manned aircraft shall apply.

ATCOs shall not be held liable for incidents or accidents resulting from the operations of UAS that are not in compliance with ICAO and/or national and/or local regulations, in non-segregated airspace.

Standardized procedures, training and guidance material shall be provided before integrating UAS into the Civil Aviation System.

IFATCA recommends the development of risk-based procedures for UAS operations whether or not UAS operations be approved.

Contingency procedures and controller training shall be provided for the management of infringements by Unmanned Aircraft.

IFATCA urges the development and implementation of technology to prevent airspace infringements by Unmanned Aircraft.

IFATCA encourages education and awareness campaigns on the use of UAS for the general public.

And is inserted in the IFATCA Technical and Professional Manual.

References

EU regulations 2019/945 and 2019/947.

https://www.faa.gov/data_research/aviation/aerospace_forecasts/media/unmanned_aircraft_systems.pdf p. 41-42.

Review of Radio Frequency Spectrum Protection Policy, WP 88, IFATCA 58th Annual Conference 2019, Conchal, Costa Rica.

Display of Unmanned Aerial System (UAS) surveillance data on Controller working position, WP 90, IFATCA 57th Annual Conference 2018, Accra, Ghana.

FAA Advisory Circular 90-48D, https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_90-48D.pdf, 19th of April 2016.

IFALPA Press Release “Global Pilots & Industry Partners call for New Guidance on Drone Operations” dated 10th of October 2019, Montreal.

FAA Fact Sheet Unmanned Aircraft Systems, March 2015.

ICAO DOC 10019 Manual on Remotely Piloted Aircraft Systems, First Edition, Montréal 2015.

https://www.skybrary.aero/index.php/Unmanned_Aerial_Systems_(UAS)

Last Update: October 2, 2020  

July 18, 2020   244   Jean-Francois Lepage    2020    

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