U.S . Department of Transportation Federal Aviation Administration Advisory Circular Subject: Automatic Dependent Surveillance-Broadcast Operations Date: 12/30/19 AC No: 90-114B Initiated by: AFS-400 Change:
In May 2010, the Federal Aviation Administration (FAA) issued Title 14 of the Code of Federal Regulations (14 CFR) part 91, §§ 91.225 and 91.227. This rule requires Automatic Dependent Surveillance-Broadcast (ADS-B) Out performance when operating in designated classes of airspace within the U.S. National Airspace System (NAS) after January 1, 2020, unless authorized by air traffic control (ATC). This advisory circular (AC) provides users of the NAS guidance regarding how to conduct operations in accordance with §§ 91.225 and 91.227. The appendices in this AC provide guidance for additional operations enabled by ADS-B, including ADS-B In.
ORIGINAL SIGNED by /s/ Robert C. Carty Deputy Executive Director, Flight Standards Service
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CONTENTS Paragraph Page
Chapter 1. Automatic Dependent Surveillance-Broadcast Operations1-1
1.1 Purpose of This Advisory Circular (AC)1-1
1.2 Audience1-1
1.3 Where You Can Find This AC1-1
1.4 What This AC Cancels1-1
1.5 Scope1-1
Chapter 2. Overview And System Description2-1
2.1 Overview2-1
2.2 ADS-B System Description2-1
2.3 ADS-B Broadcast Services2-2
2.4 Use of ADS-B In Information for Traffic Situational Awareness2-3
Chapter 3. Operational Considerations3-1
3.1 U.S. ADS-B Airspace and Equipment Performance Requirements3-1
3.2 Exceptions to Airspace Requirements3-2
3.3 Traffic Awareness Beacon System (TABS)3-2
Chapter 4. Operating Procedures4-1
4.1 General Operating Procedures4-1
4.2 Operator Familiarity of the Installed ADS-B System4-1
4.3 ADS-B Equipment Operations (U.S. Airspace)4-1
4.4 Flight Plans (FP)4-8
4.5 Preflight Requirements (U.S. Airspace)4-11
4.6 Flightcrew Entry of Required ADS-B Data4-16
Appendix A. ADS-B In-Trail ProcedureA-1
Appe
ndix B. CAVS Using ADS-B InB-1
Appendix C. ADS-B In Operations—Aircraft Qualification and MaintenanceC-1
Appendix D. DefinitionsD-1
Appendix E. Related Regulations and Reading MaterialE-1
iii CONTENTS (Continued) List of Figures Figure 3-1. Automatic Dependent Surveillance-Broadcast Airspace Rule (§ 91.225)
Diagram3-2
Figure A-1. Reduction of Aircraft Separation Minima with In-Trail ProcedureA-1
Figure A-2. In-Trail Procedure Distances IllustratedA-3
Figure A-3. Similar TrackA-4
Figure A-4. In-Trail Procedure Climb/Descent VariationsA-7
List of Tables
Table 4-1. Preflight Availability Prediction4-14
Table 4-2. A ircraft Identification Transmission Examples4-18
Table A-1. In-T rail Procedure Initiation/Maneuver Criteria (Reference RTCA DO-312
Supplement)A-11
Table A-2. F lightcrew Standardized Free Text Controller-Pilot Data Link
Communication Message Set for In-Trail ProcedureA-12
Table A-3. C ontroller Free Text Controller-Pilot Data Link Communication Message
Set for In-Trail ProcedureA-13
1-1 CHAPTER 1. AUTOMATIC DEPENDENT SURVEILLANCE-BROADCAST
OPERATIONS
1.1 Purpose of This Advisory Circular (AC). The intent of this AC is to facilitate operations using Automatic Dependent Surveillance-Broadcast (ADS-B) technology in compliance with Title 14 of the Code of Federal Regulations (14 CFR) part 91, §§ 91.225 and 91.227. The appendices provide guidance on additional ADS-B Out and ADS-B In operations that may be authorized by the Administrator.
1.2 Audience. This AC applies to all operators intending to use ADS-B within the U.S.
National Airspace System (NAS).
1.3 Where You Can Find This AC. You can find this AC on the Federal Aviation Administration’s (FAA) website at http://www.faa.gov/regulations_policies/advisory_circulars.
1.4 What This AC Cancels. AC 90-114A CHG 1, Automatic Dependent Surveillance- Broadcast Operations, dated March 7, 2016, is canceled.
1.5 Scope. This AC contains an overview of the ADS-B system and general operating procedures in compliance with the airspace and performance requirements of §§ 91.225 and 91.227. The appendices provide guidance on additional ADS-B Out and ADS-B In operations that may be authorized by the Administrator.
1.5.1 Obligation. The contents of this document do not have the force and effect of law and are not meant to bind the public in any way. This document is intended only to provide clarity to the public regarding existing requirements under the law or agency policies.
This AC is not mandatory and does not constitute a regulation. The guidance contained herein is not legally binding in its own right and will not be relied upon by the FAA as a separate basis for affirmative enforcement action or other administrative penalty.
Conformity with the guidance document is voluntary only, and nonconformity will not affect rights and obligations under existing statutes and regulations. This AC describes an acceptable means, but not the only means, to meet the requirements of 14 CFR.
1.5.2 Authorization to Conduct ADS-B Out Operations. The FAA does not require an authorization to conduct ADS-B Out operations in the airspace specified in § 91.225 (U.S. airspace). However, pilots, dispatch personnel, and maintenance personnel should be familiar with the information provided in this AC.
1.5.3 Certification and Installation of ADS-B Out Equipment. Guidance associated with the installation and airworthiness approval of ADS-B Out equipment is contained in AC 20-165, Airworthiness Approval of Automatic Dependent Surveillance-Broadcast Out Systems.
Note 1: The European Union Aviation Safety Agency’s (EASA) publication, Certification Specifications and Acceptable Means of Compliance for Airborne Communications, Navigation and Surveillance (CS-ACNS), also provides specifications associated with the installation and airworthiness approval of
1-2 ADS-B Out equipment in Europe. ADS-B equipment that complies with CS-ACNS complies with §§ 91.225 and 91.227.
Note 2: Outside the U.S. NAS, many worldwide Air Traffic Service Providers (ATSP) allow the use of ADS-B equipment certified to the EASA Acceptable Means of Compliance (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. EASA AMC 20-24 is intended for Non-Radar Areas (NRA). However, AMC 20-24 equipment does not necessarily comply with § 91.225.
2-1 CHAPTER 2. OVERVIEW AND SYSTEM DESCRIPTION
2.1 Overview. Starting with the National Airspace System (NAS)-wide implementation of ADS-B, the FAA has begun to facilitate improvements needed to increase the capacity and efficiency of the NAS while maintaining safety. ADS-B supports these improvements by providing a higher update rate and enhanced accuracy of surveillance information over the current radar-based surveillance systems. In addition, ADS-B enables the expansion of air traffic control (ATC) surveillance services into areas where none existed previously. The ADS-B ground system also provides Traffic Information Service-Broadcast (TIS-B) and Flight Information Service-Broadcast (FIS-B) for use on appropriately equipped aircraft, enhancing the user’s situational awareness (SA) and improving the overall safety of the NAS.
2.2 ADS-B System Description.
2.2.1 ADS-B System Architecture. The ADS-B system architecture is composed of aircraft avionics and an Air Traffic Service Provider (ATSP) infrastructure. Onboard “position source” avionics determine the position of the aircraft, typically by using the Global Navigation Satellite Systems (GNSS) and transmitting this and additional information about the aircraft to receiver stations for use by ATC, to ADS-B In-equipped aircraft, and to other aviation service providers.
2.2.2 ADS-B Operating Frequencies. In the United States, the ADS-B system operates on two frequencies: 1090 or 978 megahertz (MHz). See Chapter 3, Figure 3-1, Automatic Dependent Surveillance-Broadcast Airspace Rule (§ 91.225) Diagram, for airspace and frequency requirements.
2.2.2.1 The 1090 MHz Frequency. The 1090 MHz frequency is associated with current Mode A, C, and S transponder operations. ADS-B information is included in Mode S transponders’ Extended Squitter (ES) transmit messages, and referred to as 1090ES in this AC.
2.2.2.2 The 978 MHz Frequency. ADS-B equipment operating on 978 MHz are referred to as Universal Access Transceivers (UAT) in this AC.
2.2.3 ADS-B Avionics Operating Modes. ADS-B avionics can have the ability to both transmit and receive information.
2.2.3.1 ADS-B Out. The transmission of ADS-B information from aircraft is known as ADS-B Out.
2.2.3.2 ADS-B In. The receipt of ADS-B information by an aircraft is known as ADS-B In.
Note: After January 1, 2020, all aircraft operating within the airspace defined in 14 CFR part 91, § 91.225 will be required to transmit (ADS-B Out) the information defined in § 91.227 using Technical Standard Order (TSO)-C166b, Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) and
2-2 Traffic Information Service-Broadcast (TIS-B) Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz), or TSO-C154c, Universal Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on Frequency of 978 MHz, avionics.
2.3 ADS-B Broadcast Services. In the United States, ADS-B implementation includes three broadcast services: Automatic Dependent Surveillance-Rebroadcast (ADS-R), TIS-B, and FIS-B. For a detailed explanation of these services, refer to the FAA Surveillance and Broadcast Services Description Document (SRT-047).
2.3.1 ADS-R. Because the ADS-B system operates on two separate frequencies (1090 MHz and 978 MHz), there is a need to translate, reformat, and rebroadcast the information from each frequency to enable aircraft receiving on the other frequency to process and use the other’s information. This process is referred to as ADS-R and occurs within an ADS-B ground station. An aircraft or vehicle that is ADS-B Out and is receiving ADS-R service is known as an ADS-R client. An ADS-B-equipped aircraft or vehicle on the opposite link of the ADS-R client that has its messages translated and transmitted by the ground system is known as an ADS-R target. See paragraph 2.3.5 for ADS-R client qualification criteria.
Note: Aircraft operating on the same ADS-B frequency exchange information directly and do not require ADS-R translation. Aircraft with ADS-B In capability on both UAT and 1090ES do not require ADS-R service.
2.3.2 TIS-B. TIS-B is the broadcast of transponder-based Mode C or Mode S traffic information derived from ATC surveillance systems. TIS-B provides ADS-B In-equipped aircraft with a more complete picture of surrounding traffic in situations where not all aircraft are equipped with ADS-B. An aircraft or vehicle that is ADS-B Out and is receiving TIS-B service is known as a TIS-B client. A non-ADS-B-equipped aircraft or vehicle that has its position transmitted in TIS-B reports is known as a TIS-B target. See paragraph 2.3.5 for TIS-B client qualification criteria.
2.3.3 FIS-B. FIS-B operates on UAT only and provides ADS-B In-equipped aircraft with a suite of advisory-only aeronautical and weather information products to enhance the user’s situational awareness. Additional information on FIS-B and the products available through the service are provided in the Aeronautical Information Manual (AIM) and Advisory Circular (AC) 00-63, Use of Flight Deck Displays of Digital Weather and Aeronautical Information.
2.3.4 Automatic Dependent Surveillance-Same Link Rebroadcast (ADS-SLR). ADS-SLR uses ADS-R to rebroadcast ADS-B messages sent by aircraft on or near a runway; it is available at all airports with an FAA surface surveillance system. Airport structures can block reception of direct aircraft-to-aircraft ADS-B messages on an airport surface, impacting use of ADS-B In systems on an airport surface. This effect is mitigated by ADS-SLR.
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2.3.5 ADS-B Out Requirements for ADS-R and TIS-B. After January 1, 2020, the FAA will no longer use ADS-B data from equipment that does not comply with the performance requirements of either TSO-C166b or TSO-C154c to provide ATC surveillance services.
As such, after January 1, 2020, the FAA will discontinue TIS-B and ADS-R client services NAS-wide for aircraft not equipped with ADS-B Out that complies with the requirements specified in those TSOs or TSO-C199, Traffic Awareness Beacon System (TABS). Operators of ADS-B In-equipped aircraft should refer to paragraph 4.3.2.5 of this AC for additional information on ADS-B Out equipment performance requirements related to TIS-B and ADS-R.
2.4 Use of ADS-B In Information for Traffic Situational Awareness. This paragraph provides guidance on the use of ADS-B In information for traffic situational awareness.
See the appropriate appendices of this AC for guidance on the use of ADS-B In for the more advanced procedures, which may be performed if authorized. There is no specific authorization to use ADS-B In for traffic situational awareness. Installation of ADS-B In equipment is not required for compliance with § 91.225 or § 91.227. However, aircraft owners and operators who choose to voluntarily equip with ADS-B In avionics will achieve greater benefit from the technology through improved traffic situational awareness on the ground and in the air.
Note: This AC only addresses ADS-B In systems installed consistent with AC 20-172, Airworthiness Approval for ADS-B In Systems and Applications, and meeting TSO-C195a (or later revision), Avionics Supporting Automatic Dependent Surveillance-Broadcast (ADS-B) Aircraft Surveillance Applications (ASA).
2.4.1 ADS-B In Systems. Most ADS-B In systems will include a flight deck traffic display depicting the relative position and related information of ADS-B-equipped aircraft presented on a plan view. This traffic display is only one component of the input and output devices collectively known as a Cockpit Display of Traffic Information (CDTI).
The traffic display may be on a dedicated display or integrated into and presented on an existing display (e.g., navigation display (ND) or multifunction display (MFD)). The terms traffic display and CDTI are used interchangeably when the meaning is clear in context. In many installations, a moving map depicting key surface elements of the airport may be displayed when on the ground or within a predefined altitude/distance from an airport while airborne.
Note: ADS-B Traffic Advisory System (ATAS) is an ADS-B In application intended specifically for General Aviation (GA) use that will incorporate an audio traffic alerting capability. There is a configuration in which the display is optional for aircraft that cannot accommodate a display.
2.4.2 Operation. The CDTI will display nearby ADS-B Out traffic and may also display TIS-B traffic, depending on the installation and operating airspace. The display may have functionality to allow the pilot to select a target to obtain additional information that might not be automatically displayed, such as distance from own-ship and groundspeed (GS). The system will also provide range selection and declutter functionality. More
2-4 advanced ADS-B In systems may also include certified functionality to perform ADS-B In procedures described in the appendices of this AC.
Note: For traffic situational awareness, pilots are encouraged to incorporate the display in their normal scan to aid in the early detection of nearby traffic when in visual conditions and to aid in understanding the flow and amount of nearby traffic when in instrument conditions. However, the traffic display is not intended to be used for self-separation or to deviate from an ATC clearance. Should questions arise about a potential conflict with traffic while on an instrument flight rules (IFR) clearance, the pilot should query ATC. Pilots are also cautioned to not allow the display to become a distraction from the primary task of flying the aircraft, or scanning outside for traffic. Finally, pilots are cautioned against unnecessarily communicating on the ATC frequency about traffic observed on the traffic display.
2.4.3 Limitations. Pilots should understand the proper use and limitations of their equipment and should adhere to the following:
2.4.3.1 Only use the traffic display to supplement what can be seen out the window (OTW), except when authorized to conduct ADS-B In operations described in the appendices of this AC. Pilots must always conduct OTW scans to see and avoid as required under § 91.113(b).
2.4.3.2 Unless specifically certified for the function, the traffic display is not intended for collision avoidance or self-separation.
2.4.3.3 Not all ground and airborne traffic will appear on the traffic display. The traffic display can only display properly equipped ADS-B Out traffic broadcasting on the received frequencies, and, depending on the operating location, ADS-SLR, ADS-R, TIS-B, and/or Traffic Alert and Collision Avoidance System (TCAS) (if installed) traffic. Additionally, the completeness of the traffic situational awareness information is affected by range, signal quality, and proper installation and function of the ADS-B Out system on the traffic aircraft.
2.4.3.4 Unless initiated by the controller, pilots should typically not use the call sign or Aircraft Identification (ACID) of observed traffic in radio communications, as this could create confusion for both ATC and pilots monitoring the frequency.
2.4.3.5 In multipiloted aircraft, establish and comply with crew coordination procedures on the use of the CDTI and ADS-B In information to minimize head-down time.
2.4.3.6 Use of the traffic display does not change pilot or controller responsibilities.
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2.4.3.7 If at any time the presented information becomes unreliable, inoperative, or a distraction, disregard the information presented on the traffic display.
2.4.3.8 In TCAS-equipped aircraft, ADS-B In traffic display information does not change existing procedures for response to a traffic advisory (TA) and/or Resolution Advisory (RA).
3-1 CHAPTER 3. OPERATIONAL CONSIDERATIONS
3.1 U.S. ADS-B Airspace and Equipment Performance Requirements. After January 1, 2020, unless authorized by air traffic control (ATC), all aircraft operating in the airspace specified in 14 CFR part 91, § 91.225 must meet the equipment performance requirements defined in § 91.227. This chapter describes both the airspace and equipment performance requirements of §§ 91.225 and 91.227. Operators should consider the need to access ADS-B-required airspace and the performance requirements of that airspace when equipping for compliance with §§ 91.225 and 91.227.
3.1.1 Inside Class A Airspace. Operations in Class A airspace must:
1. Meet the equipment performance requirements in Technical Standard Order (TSO)-C166b, Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic Information Service-Broadcast (TIS-B) Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz) (1090ES).
2. Meet the requirements of § 91.227.
Note: Although TSO-C166b incorporates standards for TIS-B equipment, TIS-B equipage (ADS-B In) is not required for compliance with §§ 91.225 and 91.227.
3.1.2 Outside Class A Airspace. Operations within airspace defined in § 91.225, but outside Class A airspace must:
1. Meet the requirements of § 91.227; and
2. Meet the performance requirements in:
• TSO-C166b (1090ES); or
• TSO-C154c, Universal Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on Frequency of 978 MHz.
Figure 3-1. Automatic Dependent Surveillance-Broadcast Airspace Rule (§ 91.225) Diagram FL 600 18,000 MSL CLASS A | ADS-B 1090 ES Required 2,500 AGL ADS-B Not Required CLASS E | 10,000 MSL and above ADS-B Required
CLASS E Required ADS-B CLASS C CLASS B 10,000 MSL 3,000 MSL ADS-B ADS-B Required Required 12NM From Coastline 10,000 MSL Surface 10,000 MSL Surface Mode C Veil ADS-B Required Gulf of Mexico: 10,000 MSL Surface © AGL: Above Ground Level; FL: Flight Level; MSL: Mean Sea Level; NM: Nautical Miles
3.2 Exceptions to Airspace Requirements. The requirements of § 91.225(b) do not apply to any aircraft that was not originally certified with an electrical system or that has not subsequently been certified with such a system installed, including balloons and gliders.
The FAA has previously determined that the same aircraft excluded from the transponder requirement are excluded from the ADS-B Out equipage. Accordingly, an aircraft that subsequently has been installed with batteries or an electric starter would not be required to equip for ADS-B Out. These aircraft may conduct operations without ADS-B Out in the airspace specified in § 91.225(d)(2) and (4). However, for other aircraft without ADS-B Out, § 91.225(g) requires ATC authorization prior to operation in ADS-B Out-required airspace.
3.3 Traffic Awareness Beacon System (TABS). Operators of aircraft exempt from carrying a transponder or ADS-B equipment may wish to consider installing a TABS device (refer to ISO-C199, Traffic Awareness Beacon System (TABS)). TABS devices do not meet the transponder or ADS-B requirements defined in §§ 91.215 and 91.225, respectively.
However, they will allow TABS-equipped aircraft to be electronically "visible" to aircraft equipped with Traffic Alert and Collision Avoidance Systems (TCAS), Traffic Advisory Systems (TAS), and ADS-B In systems. TABS-equipped aircraft that are broadcasting an ADS-B In capability will also become TIS-B clients.
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