Advisory Circular (AC) No. 500-029

Subject: Certification of Automatic Dependent Surveillance – Broadcast (ADS-B)

Issuing Office: Civil Aviation, Standards
Document No.: AC 500-029
File Classification No.: Z 5000-34
Issue No.: 01
RDIMS No.: 16965437 v5
Effective Date: 2022-04-22

Table of contents

1.0 Introduction

(1) This Advisory Circular (AC) is provided for information and guidance purposes. It describes an example of an acceptable means, but not the only means, of demonstrating compliance with regulations and standards. This AC on its own does not change, create, amend or permit deviations from regulatory requirements, nor does it establish minimum standards.

1.1 Purpose

(1) The purpose of this document is to provide guidance to those installing and certifying Automatic Dependent Surveillance - Broadcast In (ADS-B In) and Out (ADS-B Out) Systems. It also clarifies Transport Canada’s position on the installation of Universal Access Transceivers (UAT) and 1090 MHz extended squitter (1090ES).

1.2 Applicability

(1) This document applies to all Transport Canada Civil Aviation (TCCA) employees, to individuals and organizations when they are exercising privileges granted to them under an External Ministerial Delegation of Authority. This information is also available to the aviation industry for information purposes.

1.3 Description of changes

(1) Not applicable.

2.0 References and requirements

2.1 Reference documents

(1) It is intended that the following reference materials be used in conjunction with this document:

  • (a) Subpart 21 of Part V of the Canadian Aviation Regulations (CARs) — Approval of the Type Design or a Change to the Type Design of an Aeronautical Product, 1 December 2009.
  • (b) Advisory Circular (AC) 513-003, Flight Test Considerations for the Approval of the Design of Aircraft Modifications Issue 01, 1 December 2004.
  • (c) AC 700-009, Automatic Dependent Surveillance – Broadcast Issue 03, 2 July 2021.
  • (d) Federal Aviation Administration Advisory Circular (FAA AC) 90-114B Automatic Dependent Surveillance-Broadcast Operations, 30 December 2019.
  • (e) FAA AC 20-165B, Airworthiness Approval of Automatic Dependent Surveillance - Broadcast Out Systems, 7 December 2015.
  • (f) FAA AC 20-172B, Airworthiness Approval for ADS-B In Systems and Applications, 20 May 2015.
  • (g) FAA AC 20-149B, Installation Guidance for Domestic Flight Information Service- Broadcast, 21 December 2015.
  • (h) EASA CS-ACNS. Certification Specifications (and Acceptable Means of Compliance) for Airborne Communication, Navigation and Surveillance (CS-ACNS), 17 December 2013.
  • (i) EASA AMC 20-24. Certification Considerations for the Enhanced ATS in Non-Radar Areas using ADS-B Surveillance (ADS-B-NRA) Application via 1090 MHz Extended Squitter, 25 April 2008.
  • (j) TSO-C154c. Universal Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on Frequency of 978 MHz, 02 December 2009.
  • (k) TSO-C166b. Extended Squitter Automatic Dependent Surveillance – Broadcast (ADS-B) and Traffic Information Service – Broadcast (TIS-B) Equipment Operating on the Radio Frequency 1090 Megahertz (MHz), 02 December 2009.
  • (l) TSO-C195b. Avionics Supporting Automatic Surveillance – Broadcast (ADS-B) Aircraft Surveillance Applications (ASA), 29 September 2014.
  • (m) RTCA/DO-260B. Minimum Operational Performance Standards for 1090 MHz Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic Information Services-Broadcast (TIS-B), Section 2, 2 December 2009.
  • (n) RTCA/DO-282B, Minimum Operational Performance Standards for Universal Access Transceiver (UAT) Automatic Dependent Surveillance Broadcast (ADS-B), Section 2, 2 December 2009.
  • (o) RTCA/DO-317B, Minimum Operational Performance Standards for Aircraft Surveillance Applications System, 17 June 2014.
  • (p) AIP Canada (ICAO), Aeronautical Information Publication Part 2 Enroute (ENR), 13 September 2018.

2.2 Cancelled documents

(1) Not applicable.

2.3 Definitions and abbreviations

(1) The following definitions are used in this document:

  • (a) ADS-B In function: An aircraft’s ability to receive ADS-B information, such as ADS-B messages from other aircraft or Traffic Information Services-Broadcast (TIS-B), or Automatic Dependant Surveillance-Rebroadcast (ADS-R) from the ground or satellite-based infrastructure. If capable of receiving UAT band, ADS-B In is the ability to receive Flight Information System-Broadcast (FIS-B) for countries broadcasting FIS-B data.
  • (b) ADS-B In system: A collection of ADS-B subsystems wherein ADS-B messages are received. The systems that display the information to the pilot may not be considered part of the ADS-B system, but are always considered part of the ADS-B In function.
  • (c) ADS-B Out function: An aircraft’s ability to periodically broadcast its own-ship information derived from on-board systems in a format suitable for ground infrastructure, satellite-based and ADS-B In capable receivers.
  • (d) ADS-B Out system: A collection of ADS-B subsystems wherein ADS-B messages are broadcast. The data source is not necessarily considered as part of the ADS-B system, although it is always considered part of the ADS-B Out function.
  • (e) ADS-B links: There are two ADS-B link options: 1090 MHz extended squitter and 978 MHz UAT.
  • (f) ADS-B source: Any system that is used to generate ADS-B own-ship information parameters. Typically, ADS-B sources can be any on-board systems such as GPS, FMS, air data source, attitude/heading source, and autopilot (if equipped). A system or sub-system used to convey or convert the source data into a readable format is also considered a part of the ADS-B source.
  • (g) Horizontal velocity: Ground speed vector information.

(2) The following abbreviations are used in this document:

  • (a) AC: Advisory Circular;
  • (b) ACAS: Airborne Collision Avoidance System;
  • (c) ADS-B: Automatic Dependent Surveillance Broadcast;
  • (d) ADS-R: Automatic Dependant Surveillance-Rebroadcast;
  • (e) AFM: Aircraft Flight Manual;
  • (f) CS-ACNS: Certification Specifications for Airborne Communication, Navigation and Surveillance;
  • (g) EASA: European Union Aviation Safety Agency;
  • (h) FAA: Federal Aviation Administration;
  • (i) FIS-B: Flight Information System-Broadcast;
  • (j) FMS: Flight Management System;
  • (k) GPS: Global Positioning System;
  • (l) GNSS: Global Navigation Satellite System;
  • (m) ICAO: International Civil Aviation Organization;
  • (n) MMEL: Master Minimum Equipment List;
  • (o) NACp: Navigation Accuracy Category for Position;
  • (p) NACv: Navigation Accuracy Category for Velocity;
  • (q) NIC: Navigation Integrity Category;
  • (r) NRA: Non Radar Airspace;
  • (s) SDA: System Design Assurance;
  • (t) SIL: Source Integrity Level;
  • (u) TCAS: Traffic Alert and Collision Avoidance System;
  • (v) TCCA: Transport Canada Civil Aviation;
  • (w) TSO: Technical Standard Orders;
  • (x) TIS-B: Traffic Information Services-Broadcast;
  • (y) UAT: Universal Access Transceiver;
  • (z) US: United States; and
  • (aa) 1090ES: 1090 MHz extended squitter.

3.0 Background

(1) ADS-B is a datalink-based broadcast surveillance system. It is automatic and periodically sends aircraft information without external interrogation. An ADS-B system provides Performance Based Surveillance functions as an aid to, or instead of, ground radar based surveillance. ADS-B allows Air Traffic Management agencies and other appropriately equipped aircraft to monitor the position of ADS-B Out equipped aircraft. Space-Based ADS-B receivers increase ADS-B coverage, including coverage in remote areas where ground based ADS-B receivers are not available/ within line of sight.

3.1 ADS-B Out

(1) Previous versions of TCCA AC 700-009 referred to European Union Aviation Safety Agency (EASA) AMC 20-24. EASA AMC 20-24 was recognized as the operational standard for ADS-B Out performance in Non Radar Airspace (NRA). It established the interoperability requirements that permit air traffic services to be provided. In 2013, Certification Specifications for Airborne Communication, Navigation and Surveillance (CS-ACNS) introduced more comprehensive and updated ADS-B Out requirements for controlled airspaces. The CS ACNS.D.ADSB clarifies that: “The requirements of CS ACNS.D.ADSB fully cover (and exceed) the requirements of AMC 20-24 (Certification considerations for the enhanced air traffic system in NRA using ADS-B Surveillance Application via 1090ES). Therefore, aircraft that comply with EASA CS ACNS.D.ADSB also comply with EASA AMC 20-24 but not vice versa”. One of the requirements added in CS ACNS.D.ADSB is the System Design Assurance (SDA), which TCCA considers essential, see paragraph 4.2(1)(s) of this AC.

(2) The Federal Aviation Administration (FAA) published its own guidance document at FAA AC 20-165B Airworthiness Approval of Automatic Dependent Surveillance – Broadcast Out Systems. Since Canadian Operators invariably wish to fly in United States (US) Airspace, TCCA predominantly harmonizes with FAA standards and guidance. Consequently, this AC aligns with the FAA AC 20-165B. Applicants must ensure that documentation related to their ADS-B installations clearly identifies which requirements are met and the areas of operation for which the ADS-B installation certification is intended. For certification of ADS-B Out functionality in Canada, installations must meet the requirements of the aircraft Type Certification Basis and, unless otherwise noted, the guidance of FAA AC 20-165B applies to ADS-B Out systems testing and installation.

(3) It is incumbent on the applicant to ensure that certification aspects required by a validating authority are addressed. There are some differences between the FAA and EASA certification requirements for ADS-B Out installations and these differences are listed in each agency’s guidance material. Section 4.2 of this AC states the messages deemed essential for certification in Canada. It also states the FAA and EASA essential messages if operation in those airspaces is sought.

(4) In Canada, ADS-B receivers are only compatible with 1090ES ADS-B Out equipment. Although UAT is an option for equipage to meet the FAA Operating Rule for aircraft operations below 18,000ft, in US airspace, a Canadian equipped ADS-B Out in the UAT band will only be received by aircraft equipped with a UAT band ADS-B In system.

(5) Refer to TCCA AC 700-009 for air operator requirements with ADS-B equipped aircraft.

3.2 ADS-B In

(1) Aircraft equipped with ADS-B In systems are able to receive ADS-B Out, ADS-R, FIS-B and TIS-B transmissions for improved situational awareness. The sensitivity of the ADS-B In receiver is such that only those transmissions from aircraft within a defined distance/range from the receiving aircraft are detected; this prevents the aircraft display from being inundated with reports. There is currently no mandate for ADS-B In equipage in Canada.

(2) In Canada, ADS-B In systems will be capable of receiving ADS-B Out data from aircraft that are in line of sight and emitting in the 1090ES and/or UAT bands. UAT is also an option for equipage to meet the FAA Operating Rule for aircraft operations below 18,000ft, in US airspace. In the US, the UAT band is used to provide a number of other services including graphical National Weather Service products, temporary flight restrictions, and special use airspace information via FIS-B, and traffic reporting services via TIS-B. TIS-B, FIS-B, and ADS-R services are not available in Canada, and therefore, other aircraft ADS-B Out information is the only data that will be received.

4.0 Means of compliance

4.1 Functional requirements

(1) For new installation approvals, TCCA requires applicants to comply with RTCA/DO-260B. To receive space-based ADS-B surveillance services, the applicant must ensure that the installation meets the performance standards required by the air navigation service provider.

(2) Except for ADS-B Out systems that meet CS-ACNS or FAA AC 20-165B, the ADS-B links must meet the performance requirements stated in Technical Standard Orders (TSO) TSO-C166b for 1090ES, or TSO-C154c for UAT.

(3) ADS-B Out systems must be integrated with a position source that meets the minimum performance requirements specified in one or more of the following:

  • (a) TSO-C129, Airborne Supplemental Navigation Equipment Using the Global Positioning System (GPS);
  • (b) TSO-C145, Airborne Navigation Sensors Using the Global Position System (GPS) Augmented by the Satellite Based Augmentation System (SBAS);
  • (c) TSO-C146, Stand-Alone Airborne Navigation Equipment Using the Global Positioning System (GPS) Augmented by the Satellite Based Augmentation System (SBAS); or
  • (d) TSO-C196, Airborne Supplemental Navigation Sensors for Global Positioning System Equipment using Aircraft-Based Augmentation.

(4) In order to obtain Surveillance Service by air traffic control for areas utilizing ADS-B, in accordance with AIP Canada ENR 1.6.3, the ADS-B Out system must transmit, as a minimum, all essential data.

(5) For guidance to obtain installation approval for ADS-B In equipment, please refer to FAA AC 20-172B, Airworthiness Approval for ADS-B In Systems and Applications.

4.2 ADS-B Out data

(1) TCCA considers that ADS-B Out must transmit essential ADS-B data correctly using 1090ES to enable NRA surveillance services by NAV CANADA. Erroneous data must not be transmitted which may provide false information to aircraft equipped with ADS-B In systems. ADS-B Out system that are unable to send the essential data must disable ADS-B transmission unless the aircraft transmits a value of 0 (zero) for one or more of the Position Integrity Indicators. The following list is the TCCA essential ADS-B Out data:

  • (a) A unique International Civil Aviation Organization (ICAO) 24-bit aircraft address (contained within each ADS-B message transmission);
  • (b) Surface Horizontal Position (latitude and longitude);
  • (c) Special Position Identification;
  • (d) Emergency Status and Emergency Indicator;
  • (e) Aircraft Identification (Call Sign, Flight ID, or registration number);
  • (f) Airborne Horizontal Position (latitude, longitude);
  • (g) Barometric Pressure Altitude;
  • (h) Transponder IDENT (when in use);
  • (i) Emitter Category;
  • (j) Geometric Altitude;
  • (k) Ground Track Angle (required when on the ground if heading is not transmitted);
  • (l) Horizontal Velocity (including surface ground speed);
  • (m) Length and Width of Aircraft;
  • (n) Mode 3/A Code;
  • (o) Navigation Integrity Category (NIC);
  • (p) Navigation Accuracy Category for Position (NACp);
  • (q) Navigation Accuracy Category for Velocity (NACv);
  • (r) Source Integrity Level (SIL);
  • (s) System Design Assurance (SDA);
  • (t) Version Number;
  • (u) TCAS Installed and Operational; and
  • (v) TCAS Traffic Status.

(2) In addition to the data set of paragraph 4.2(1), the FAA requires the following essential data to be transmitted:

  • (a) ADS-B In Capability.
  • Note: The FAA requires Position Integrity Indicator values of NACp ≥ 8, NACv ≥ 1, NIC ≥ 7, SIL = 3, and SDA ≥ 2.

(3) In addition to the data set of paragraph 4.2(1), EASA requires the following essential data set to be transmitted:

  • (a) GPS Antenna Longitudinal Offset;
  • (b) Geometric Altitude Quality (GVA); and
  • (c) Vertical Rate.

Note: EASA requires Position Integrity Indicator values of NACp ≥ 7, NACv ≥ 1, NIC ≥ 6, SIL = 3 and SDA ≥ 2.

(4) Any other data is considered non-essential. TCCA recommends that all non-essential ADS-B data be transmitted, however its transmission is not required.

(5) The FAA and EASA may have specific position accuracy requirements specific for compliance with FAA AC 20-165B and CS-ACNS. These accuracy requirements will differ. Refer to these documents for the minimum accuracy requirements.

4.3 Aircraft Flight Manual and Flight Manual Supplement

(1) The flight manual must include ADS-B operating limitations, normal operating procedures, and a system description. Additionally, some other countries require mention of their operational and airworthiness requirements. It is acceptable to include this mention in the limitation, procedure or system description section.

(2) If the aircraft is being certified in Canada only, no specific flight manual statement is required.

(3) If the aircraft is being certified to fly in both the US and Canada, the flight manual must state:

The installed ADS-B Out system has been shown to meet the equipment requirements of 14 CFR §91.227.

(4) If the aircraft is being certified to fly in Europe and Canada, the flight manual must state the following:

The installed ADS-B Out system is fully compliant with the requirements of CS ACNS.D.ADSB (1090 MHz Extended Squitter ADS-B Out).

(5) If the aircraft is being certified to fly in US, Europe and Canada, the flight manual must state:

The installed ADS-B Out system is fully compliant with the requirements of CS ACNS.D.ADSB (1090 MHz Extended Squitter ADS-B Out), and has been shown to meet the equipment requirements of 14 CFR §91.227.

(6) Any deviation from these requirements must be included in the flight manual. Particularly, any ADS-B data that is considered essential by the FAA or EASA but that is not transmitted, has to be clearly stated in the AFM or AFM Supplement; see paragraphs 4.2(2) and 4.2(3) for the ADS-B essential data.

4.4 Master Minimum Equipment List (MMEL)

(1) The serviceability of the ADS-B equipment fitted is to be noted in the MMEL, if an MMEL is required. TCCA has adopted the FAA policy letter PL-105 Rev 2 for MMEL dispatch and repair interval.

4.5 Flight Test requirements

(1) The requirements to Flight Test and Ground Test an ADS-B system installation should be assessed on a case by case basis. In general the following guidance should be considered:

  • (a) For ADS-B Out certification, just like for any other system certification, the applicant must own intellectual property for the flight test data. Any similarity claim must be substantiated with data. TCCA has not adopted FAA Policy Letter PL N 8900-362 as it does not meet Canadian Intellectual Property Laws. If the flight test data is not available for a specific equipment combination (source and ADS-B system) for one of the following reasons, then the installation should be flight tested in accordance with FAA AC 20-165B:
    • (i) Source and ADS-B pair has not been previously implemented;
    • (ii) ADS-B is implemented on a particular aircraft type for the first time; or
    • (iii) The applicant does not own intellectual property for an ADS-B installation flight test data.
  • (b) Flight Test considerations include signal attenuation due to airframe blanking, and dynamic data source output timing issues, which may not be apparent during a ground or level flight test but may appear during manoeuvring flight. Post flight analysis should note any change in received power or errors in position and altitude.
  • (c) Thorough ground test is recommended to ring out system connectivity and message set transmission prior to flight test. Each function of the ADS-B system should be tested. A pitot static and a Nav/Comm flight line test set are normally required to test the installation as per FAA AC 20-165B. It may be required to taxi or tow the aircraft to activate the ADS-B transmission of some messages, and qualified personnel may be required to test the transponder code change (including emergency codes). A thorough analysis of the transmitted data is required to confirm each functionality.
  • (d) If an ADS-B installation is embodied and acceptable flight tests data is available from a previous installation (with the exception of paragraph 4.5(1)(a)), then a ground test of the essential ADS-B data set is adequate along with the activation of any fault indications.

(2) Currently, the only method to accomplish a Flight Test is to fly within the ADS-B service coverage and accomplish a post-flight analysis of recorded data. Refer to FAA AC 20-165B for coordinating with the FAA to use their data retrieval and data analysis program.

4.6 Space-based ADS-B

(1) Space-based ADS-B provides the broadcast surveillance system previously described through the use of a satellite constellation of receivers, instead of utilizing the traditional ground-based radio receiver towers.

(2) The requirements to Flight Test and Ground Test an ADS-B system installation utilizing space-based receivers should be assessed on a case-by-case basis. The methods of compliance should be reflective of the individual system when it comes to the validation of the data-link with respect to testing using ground-based or space-based receivers. However, performance of all systems must adhere to the requirements set out in this AC, regardless of the type and location of the receiver.

4.7 Additional considerations

(1) Installation of ADS-B Out cannot be addressed solely on a non-hazard basis. DO-260B, Minimum Operational Performance Standards for 1090 MHz Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-B), identifies the transmission of incorrect ADS-B Out messages for use by other aircraft or Air Traffic Control for separation services as a Major failure condition. Consequently, the system must function correctly when installed and must meet the applicable minimum operational performance standards to ensure that the required integrity and accuracy requirements are met. Moreover, the provisions in FAA AC 23.1309-1 that allow reduction in failure probabilities and design assurance for aircraft under 6,000 pounds do not apply to the ADS-B Out system. The ADS-B installation must meet the applicable certification requirements identified in the Aircraft Type’s Certification Basis and the guidance in the applicable advisory information. Field approvals are not available in Canada and design change installations must be approved.

(2) While the focus is on the ADS-B source and ADS-B system pairing, where certification by similarity is proposed; installation design data must be presented that substantiates the similarity argument. If an aircraft interface type has changed which links a system providing aircraft source data to the ADS-B system for subsequent transmission, for example from ARINC 429 to a Recommended Standard interface, then the flight test must capture data that has been transmitted across that changed interface.

(3) Documentation of the approved configuration should identify the part number (hardware and software) of data sources that are capable of providing ADS-B source data for transmission. Integrated equipment capable of affecting compliance should also be identified. Provisions for additional data sources that were not evaluated for the approval should be identified; for example, a second GPS not installed. The documentation should be prepared in a form that may be used to conform the installation of a particular aircraft for operational approval and to perform a conformity inspection when such an inspection is recommended by maintenance instructions.

(4) One of the parameters transmitted by ADS-B Out is the Aircraft Identification. For Transport Category aircraft this is typically the call sign for the aircraft. For General Aviation aircraft it may be the aircraft registration number. When aircraft are sold overseas and are registered under a new regulatory authority, it may be necessary to change the ADS-B Out aircraft identification information. Guidance on how to change the aircraft identification information transmitted by ADS-B Out should be provided to the aircraft operator. Aircraft Operators must ensure that the correct ADS-B Out aircraft identification information is being transmitted for the area of operation. Crew operating instructions for the ADS-B should emphasise the need to use the ICAO format, as identified in ICAO Doc 4444 for entry of Flight ID or Registration Mark as applicable to the flight.

(5) Operators equipping for ADS-B in Canada may consider installing antennas on the underside of the fuselage for line of sight to ground based ADS-B receivers. However, this may not be ideal for connectivity to space-based ADS-B receivers, which is now available in Canadian airspace. The EASA CS ACNS.D.ADSB requires ADS-B antenna diversity which should improve connectivity to both ground and space based ADS-B receivers. The FAA AC 20-165B does not require antenna diversity, and requires installing antennas on the underside of the fuselage for single antenna systems.

5.0 Instructions for Continued Airworthiness

(1) Periodic maintenance tests, as per equipment manufacturer’s guidance, of ADS-B systems are recommended to ensure that ADS-B systems perform as intended. Tests should include correct functioning of system fault detection. ADS-B testing periodicity should be the same as that for other air traffic control-based transponders (e.g. Mode S), in accordance with Standard 625, Aircraft Equipment and Maintenance Standard.

6.0 Document history

(1) Not applicable.

7.0 Contact us

(1) It is recommended that applicants for an aircraft modification communicate with their TCCA Regional Aircraft Certification office to determine the acceptability and completeness of the proposed tests prior to conducting the flight test. Regional Engineers and Delegates will communicate with TCCA Flight Test to confirm the need to conduct a flight test assessment of the modified aircraft; early notification is recommended.

For more information, please contact:
Aircraft Certification Standards (AARTC)

We invite you to provide us with your suggestions for amendment to this document. Submit your comments to:

Civil Aviation Communications Centre

Original signed by

Felix Meunier
Director, Standards branch
Civil Aviation
Transport Canada