AC 90-114B

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.

Robert C. Carty

Deputy Executive Director, Flight Standards Service

12/30/19 AC 90-114B

CONTENTS

Paragraph Page

Chapter 1. Automatic Dependent Surveillance-Broadcast Operations ........................................ 1-1

1.1 Purpose of This Advisory Circular (AC) ...................................................................... 1-1

1.2 Audience ....................................................................................................................... 1-1

1.3 Where You Can Find This AC...................................................................................... 1-1

1.4 What This AC Cancels.................................................................................................. 1-1

1.5 Scope ............................................................................................................................. 1-1

Chapter 2. Overview And System Description ............................................................................ 2-1

2.1 Overview ....................................................................................................................... 2-1

2.2 ADS-B System Description .......................................................................................... 2-1

2.3 ADS-B Broadcast Services ........................................................................................... 2-2

2.4 Use of ADS-B In Information for Traffic Situational Awareness ................................ 2-3

Chapter 3. Operational Considerations ........................................................................................ 3-1

3.1 U.S. ADS-B Airspace and Equipment Performance Requirements ............................. 3-1

3.2 Exceptions to Airspace Requirements .......................................................................... 3-2

3.3 Traffic Awareness Beacon System (TABS) ................................................................. 3-2

Chapter 4. Operating Procedures ................................................................................................. 4-1

4.1 General Operating Procedures ...................................................................................... 4-1

4.2 Operator Familiarity of the Installed ADS-B System ................................................... 4-1

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 Data ................................................................ 4-16

Appendix A. ADS-B In-Trail Procedure .................................................................................. A-1

Appendix B. CAVS Using ADS-B In .......................................................................................B-1

Appendix C. ADS-B In Operations—Aircraft Qualification and Maintenance .......................C-1

Appendix D. Definitions........................................................................................................... D-1

Appendix E. Related Regulations and Reading Material.......................................................... E-1

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CONTENTS (Continued)

List of Figures

Figure 3-1. Automatic Dependent Surveillance-Broadcast Airspace Rule (§ 91.225)

Diagram................................................................................................................... 3-2

Figure A-1. Reduction of Aircraft Separation Minima with In-Trail Procedure....................... A-1

Figure A-2. In-Trail Procedure Distances Illustrated ................................................................ A-3

Figure A-3. Similar Track ......................................................................................................... A-4

Figure A-4. In-Trail Procedure Climb/Descent Variations ....................................................... A-7

List of Tables

Table 4-1. Preflight Availability Prediction ........................................................................... 4-14

Table 4-2. Aircraft Identification Transmission Examples .................................................... 4-18

Table A-1. In-Trail Procedure Initiation/Maneuver Criteria (Reference RTCA DO-312

Supplement) ......................................................................................................... A-11

Table A-2. Flightcrew Standardized Free Text Controller-Pilot Data Link

Communication Message Set for In-Trail Procedure .......................................... A-12

Table A-3. Controller Free Text Controller-Pilot Data Link Communication Message

Set for In-Trail Procedure .................................................................................... A-13

12/30/19 AC 90-114B

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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

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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.

12/30/19 AC 90-114B

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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

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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

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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.

12/30/19 AC 90-114B

2-5

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).

12/30/19 AC 90-114B

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.

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Figure 3-1. Automatic Dependent Surveillance-Broadcast Airspace Rule (§ 91.225)

Diagram

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 TSO-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.

12/30/19 AC 90-114B

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CHAPTER 4. OPERATING PROCEDURES

4.1 General Operating Procedures. This chapter describes the general procedures for

ADS-B Out operations in accordance with 14 CFR part 91, §§ 91.225 and 91.227. All

operators should use this information when planning and conducting operations requiring

ADS-B Out performance.

4.2 Operator Familiarity of the Installed ADS-B System.

4.2.1 System Operation Familiarity. All operators should use the applicable Airplane Flight

Manual (AFM), Aircraft/Airplane Flight Manual Supplement (AFMS), Rotorcraft Flight

Manual (RFM), Rotorcraft Flight Manual Supplement (RFMS), pilot’s operating

handbook (POH), or other required operating handbooks or manuals to become familiar

with the proper operation of the installed ADS-B system and any procedures expected of

the user for indications of reduced performance or failures within the system.

4.2.2 Understanding Failure Indicators Within the System. Because many ADS-B system

installations will be upgrades to existing transponders (Mode S), there may be limited

ability to indicate ADS-B failures. Mode S transponders with ADS-B functionality may

indicate a device failure (loss of transponder/ADS-B) and input failures (loss of position

source, such as the Global Navigation Satellite System (GNSS)) with the same indicator

light. Operators should refer to their AFM, AFMS, RFM, RFMS, POH, and other

handbooks and manuals for information on the differences between device failures and

function failures and the implications and procedures associated with each failure type. In

particular, normal GNSS signal interference on the ground caused by nearby obstacles,

such as a large hangar, may be incorrectly interpreted as a failure of the ADS-B system.

Moving the aircraft clear of obstructions may be all that is needed to clear an indicated

malfunction caused by GNSS multipath signals.

4.2.3 Transponder Operation and ADS-B Transmissions. For ADS-B system installations

integrated within a transponder that share control features, operators should be aware that

disabling the transponder may also disable ADS-B transmissions, as well as result in a

loss of Secondary Surveillance Radar (SSR) services and Traffic Alert and Collision

Avoidance System (TCAS)/TCAS II operation, if so equipped.

4.3 ADS-B Equipment Operations (U.S. Airspace).

4.3.1 Transmit Requirements. In accordance with § 91.225(f), each person operating an aircraft

equipped with ADS-B Out must operate this equipment in the transmit mode at all times,

unless authorized by the FAA or directed by air traffic control (ATC). This equipment

operation requirement pertains to all phases of flight operation, including airport surface

movement area operations. Pilots should select the transponder mode that enables the

altitude reporting and ADS-B Out transmissions any time their aircraft is positioned on

any portion of an airport movement area.

Note: Aircraft must comply with the appropriate Technical Standard

Order (TSO) performance requirements when transmitting ADS-B

data.

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4.3.1.1 Departures. Select the transponder mode that allows altitude reporting, and

enable ADS-B Out during pushback or taxi-out from parking spot. Select TA

or TA/RA (if equipped with TCAS) when taking the active runway.

4.3.1.2 Arrivals. After clearing the active runway, if TCAS-equipped (TA or

TA/RA), select the transponder to altitude reporting mode, and maintain

ADS-B Out transmissions. Select “STBY” or “OFF” for the transponder and

ADS-B only upon arriving at the aircraft’s parking spot or gate.

4.3.1.3 Formation Operations. ATC uses established transponder and ADS-B

transmission procedures when participating in formation operations. Per the

Aeronautical Information Manual (AIM) paragraph 4-1-20, if the formation

flight is receiving ATC services, pilots can expect ATC to direct all non-lead

aircraft to “STOP SQUAWK,” and should not do so until instructed. For

visual flight rules (VFR) formation flights not receiving ATC services, ATC

directs that only the lead aircraft should squawk the assigned beacon code

(1200). All other aircraft should disable transponder and ADS-B transmissions

once established within the formation.

4.3.1.4 Inoperative ADS-B Out. For operations with inoperative ADS-B Out comply

with the requirements of § 91.213 as appropriate for your aircraft. If you

intend to operate in airspace described in § 91.225, refer to paragraph 4.3.3

and comply with § 91.225(g)(1).

4.3.2 Equipment Qualification Requirements. In order to operate an aircraft in airspace defined

in § 91.225, the ADS-B Out equipment installed, and its connected or internal position

source, must meet the performance requirements of the applicable TSOs and meet the

requirements of § 91.227. Since § 91.225 requires the equipment components be

installed, portable ADS-B Out equipment, including system components and antennas,

does not comply with the rule. Operators should also note that FAA regulations require

installed equipment to function as intended. Under 14 CFR part 21, installed equipment

need not be manufactured under a TSO authorization, but must be approved or qualified

according to the type of aircraft as follows:

4.3.2.1 Type-Certificated Aircraft. ADS-B Out systems and equipment (including

the connected position source) installed or used in type-certificated aircraft

must have a design approval issued under part 21 or must be installed by field

approval, if appropriate. AC 20-165, Airworthiness Approval of Automatic

Dependent Surveillance—Broadcast OUT Systems, provides guidance on

installation of ADS-B Out systems. FAA Policy Memorandum, Installation

Approval for ADS-B OUT Systems, dated 2016, provides information on how

ADS-B systems may be installed by field approval.

4.3.2.2 Special Light-Sport Aircraft (SLSA). Equipment installed on SLSA must be

installed in accordance with an applicable consensus standard and must be

authorized by the aircraft’s manufacturer or a person acceptable to the FAA

(refer to part 21, § 21.181).

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4.3.2.3 Experimental Aircraft, Including Experimental Light-Sport Aircraft

(ELSA).

4.3.2.3.1 For experimental category aircraft, including ELSA, there is no FAA approval

required for the ADS-B Out system installation. However, to protect all users

of the National Airspace System (NAS), it is essential for all aircraft,

including experimental and ELSA, to install equipment that has been

adequately designed and tested to meet the equipment’s intended functions of

supporting safe ATC separation services and providing accurate traffic

awareness to other aircraft. To meet this requirement, owners of these aircraft

may elect to install equipment manufactured under a TSO authorization, in

accordance with the installation instructions provided by the manufacturer.

Alternatively, owners of these aircraft may elect to install equipment that are

not approved under a TSO authorization. For non-TSO equipment, the owner

should obtain installation instructions that include a statement of compliance

from the applicable avionics manufacturer(s). To qualify non-TSO equipment

as compliant for operations in ADS-B airspace defined in § 91.225, the

statement of compliance should indicate that when installed in accordance

with the installation instructions, the equipment complies with all

requirements of § 91.227, and with the performance requirements of the

appropriate TSO. While the statement of compliance is important in equipping

the aircraft, per § 91.225, correct installation is critical for the equipment to

operate properly.

4.3.2.3.2 Owners of experimental aircraft should retain the installation instructions

from the equipment supplier, including the statement of compliance, in the

aircraft records to support the equipment’s compliance with the requirements

of §§ 91.225 and 91.227, and to assist in resolving in-service issues if

necessary.

4.3.2.4 All Aircraft—Importance of Proper Installation. Experience with FAA

compliance monitoring of ADS-B Out-equipped aircraft to date has revealed

that a large percentage of equipped aircraft have deficiencies with ADS-B Out

system performance following initial installations. Many of these deficiencies

have been attributed to improper installation and incorrect system

configuration. Therefore, the FAA considers it particularly important for

equipment manufacturers to provide installation instructions that are as clear

and easy to follow as possible and revise these instructions when deficiencies

in the instructions are discovered. Installers should adhere to the

manufacturer’s installation instructions and employ practices that consistently

result in ADS-B Out system installations that fully comply with § 91.227

equipment performance requirements.

4.3.2.5 All Aircraft—ADS-B Out Equipment Performance and FAA Monitoring.

4.3.2.5.1 The ADS-B Out rule does not impose additional continued/recurrent

airworthiness inspection requirements for applicable equipment. Therefore,

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owner/operators of ADS-B Out-equipped aircraft should ensure continued

compliance of applicable equipment performance requirements following

initial installation or any subsequent alteration to the system.

Note: Transponder-based ADS-B Out systems (i.e., 1090ES) are still

required to meet the requirements of § 91.413.

4.3.2.5.2 The FAA continuously monitors the equipment performance of all

ADS-B Out-equipped aircraft operating in U.S. airspace for compliance of

regulatory requirements specified in § 91.227. Applicable equipment

performance monitoring is conducted by a tool known as the ADS-B

Performance Monitor (APM).

4.3.2.5.3 The APM collects data transmitted by ADS-B Out-equipped aircraft

monitored on the surface and airborne. The APM applies established

compliance criteria to collected data for more than 40 individual equipment

performance checks, assembles relevant information into a flight record, and

identifies exceptions to applicable regulations to support various internal and

external reporting requirements. Aircraft identified by the APM with

exceptions are referred to as non-performing equipment (NPE).

4.3.2.5.4 While the term NPE is generally used to describe aircraft with ADS-B Out

equipment performance exceptions, certain pilot actions can result in NPE

conditions. Such pilot actions may include the following:

1. Movement of aircraft on the surface (under its own power) or while

airborne with ADS-B Out equipment turned off;

2. Operating with a non-conforming or unauthorized (local call-sign) flight

identification (FLT ID) code;

3. Operating with a FLT ID code that does not correspond to the code filed

on an associated flight plan (FP) (as applicable);

4. Operating with barometric altitude reporting off (when not directed to do

so by ATC);

5. Operating a Universal Access Transceiver (UAT) transponder-dependent

device with the transponder turned off (no barometric altitude or

Mode 3/A code present in ADS-B messages); and

6. Operating ADS-B Out equipment in any manner contrary to applicable

regulations.

4.3.2.5.5 As discussed in paragraph 4.2, pilots should be familiar with the operation of

ADS-B Out equipment, including any associated failure indications provided

by the system. It is important for pilots to understand that most ADS-B failure

indications are limited to system component failures; and indications

associated with equipment performance required by regulation are not

provided.

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4.3.2.5.6 To enable public access to ADS-B equipment performance data needed for

owner/operators to verify compliance with § 91.227 requirements, the FAA

provides a free, web-based service called the Public ADS-B Performance

Report (PAPR) at https://adsbperformance.faa.gov/PAPRRequest.aspx.

Additional information on the PAPR service can be found at

https://www.faa.gov/nextgen/equipadsb/.

4.3.2.5.7 The FAA recommends that owner/operators of ADS-B Out-equipped aircraft

verify equipment performance through periodic use of the PAPR request

service, especially following initial equipment installation, modification, or

maintenance of existing ADS-B Out systems (including component software

updates/changes).

4.3.2.6 Handling of Aircraft with Non-Performing Equipment (NPE).

4.3.2.6.1 When ADS-B Out equipment performance becomes deficient during flight,

ATC may direct the pilot to discontinue ADS-B Out transmissions pursuant to

§ 91.225(f)(2). The pilot should comply with the procedures established for

that aircraft or notify ATC if unable. If necessary, ATC may direct the aircraft

to exit § 91.225 airspace.

4.3.2.6.2 FAA flight monitoring has shown that aircraft engaged in aerobatic and

agricultural operations may fail to meet applicable equipment performance

requirements due to maneuvering that exceeds the design limits of the

installed GNSS equipment. Aircraft identified by the APM with exceptions to

§ 91.227 resulting from maneuvering characteristics of aerobatic and/or

agricultural operations are not considered NPE by the FAA. When not

actively engaged in aerobatics or agricultural operations (e.g., when transiting

to and from applicable areas of operation), these aircraft are expected to meet

ADS-B Out equipment performance requirements.

4.3.2.6.3 In late 2017, the FAA published a notice (82 FR 60302) to the Federal

Information Service-Broadcast (TIS-B) (refer to Docket Number

FAA-2017-1194, Change to Automatic Dependent Surveillance Broadcast

Services, at https://www.federalregister.gov/). These changes included

implementation of a filter within the FAA ATC automation system to prevent

processing of data transmitted by certain NPE aircraft. Application of the filter

is enabled by restricting use of the 24-bit International Civil Aviation

Organization (ICAO) address (Mode S code) transmitted from NPE aircraft

and managed through a list referred to as the No Services Aircraft List

(NSAL). NPE aircraft on the NSAL cannot be provided ATC services via the

ADS-B data network and do not meet the equipment performance

requirements necessary to qualify for TIS-B client services. Owner/operators

of aircraft on the NSAL must seek authorization from ATC to operate in the

airspace specified by § 91.225.

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4.3.2.6.4 Prior to listing NPE aircraft on the NSAL, the FAA will provide written

notification of relevant ADS-B equipment issues to the owner/operator and

address associated with the aircraft’s registry in an effort to coordinate NPE

corrective action. In most instances, a 45-day period is allowed from the date

associated with the FAA notification letter to complete NPE corrective action.

All NPE aircraft are subject to NSAL listing after the 45-day period has

elapsed and corrective action has not been completed.

Note: NPE notifications mailed to unmonitored mailboxes may result

in aircraft being listed to the NSAL (after 45 days) without

owner/operator awareness. Owner/operators with addresses associated

with an unmonitored mailbox (e.g., LLC or non-resident addresses) are

advised to request a PAPR for awareness of ADS-B Out equipment

performance and the NSAL status of their aircraft.

4.3.2.6.5 The operation of aircraft with certain NPE characteristics (e.g., erroneous

position reports) present a significant safety hazard to surrounding airspace

and ATC services. Hazardous NPE aircraft may require immediate placement

on the NSAL to mitigate applicable safety risks prior to owner/operator

notification.

4.3.2.6.6 In rare cases, it is necessary for the FAA to issue an Aircraft Condition Notice

(FAA Form 8620-1) to prevent operation of aircraft with hazardous NPE

characteristics.

4.3.2.6.7 Owner/operators receiving an NPE notification letter and/or Aircraft

Condition Notice should follow the instructions provided in those documents

and contact the handling aviation safety inspector (ASI) as soon as possible to

coordinate required corrective action. Following NPE corrective action, a

verification flight must be conducted pursuant to § 91.407(b), and the

handling ASI should be notified, to validate equipment performance. When

the handling ASI determines the NPE condition has been corrected, they will

notify the owner/operator and, when applicable, initiate the process for

removal of the aircraft from the NSAL.

Note: Once requested, removal of aircraft from the NSAL can take up

to 30 days.

4.3.2.6.8 Aircraft on the NSAL are identified on the cover page of an applicable PAPR

with the following language (in red font): Aircraft is on No Services List. This

language is omitted from a PAPR associated with aircraft not currently on the

NSAL. See paragraph 4.3.2.5.6 for information on obtaining a PAPR.

4.3.3 Operation of Aircraft with Inoperative ADS-B. Section 91.225(g) permits ATC to

authorize the operation of aircraft with inoperative ADS-B or that do not have ADS-B

installed into airspace where it is required. Under § 91.225(g), operators must make

requests for ATC-authorized deviations from the requirements in § 91.225 to the ATC

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facility that has jurisdiction over the concerned airspace or airport movement area within

the time periods specified below:

1. For operation of an aircraft with inoperative ADS-B equipment to the airport of

ultimate destination (including any intermediate stops) or to proceed to a place where

suitable repairs can be made, or both, the request may be made at any time.

2. For operation of an aircraft that is not equipped with ADS-B, operators must make

the request at least 1 hour before the proposed operation.

4.3.3.1 Air Carriers Procedures. Air carriers are not precluded from using the

ADS-B Deviation Authorization Preflight Tool (ADAPT); however, the Air

Traffic Control System Command Center (ATSCSS) will facilitate

coordination with FAA facilities for flights that are equipped with ADS-B that

is inoperative. Collaborative Decision Making (CDM) participants should use

the Tactical Customer Advocate (TCA) webpage or call the TCA desk with

the call sign, proposed departure time, requested route of flight, and requested

altitude. The TCA will coordinate with all FAA facilities along the route of

flight. Approval/denial will be provided with any restrictions to the

route/altitude for the operation of the flight with the failed

ADS-B/transponder.

4.3.3.2 All Other Operators. All other operators are encouraged to use ADAPT to

document your request and authorization (see paragraph 4.3.5). You may also

request coordination through the departure airport ATC tower. The tower will

initiate the coordination of the request.

Note 1. Aircraft must have an operable Mode C transponder in order

to use ADAPT. If the failure results in the loss of all transponder

functions, you must coordinate through the ATCSCC or the local

facility, as appropriate, or use your existing procedures for an

inoperative transponder.

Note 2. All airborne failures will be handled by the FAA facility

where the failure occurs. The FAA facility will coordinate through the

ATCSCC if necessary, who will then coordinate with all FAA

facilities along the remaining route of flight.

4.3.4 Operation of Aircraft Not Equipped With ADS-B. In April 2019, the FAA published a

notice (84 FR 12062) to the Federal Register clarifying policy for authorizations to

operators of aircraft not equipped with ADS-B (refer to Docket Number FAA-2019-0239,

Statement of Policy for Authorizations to Operators of Aircraft That are Not Equipped

With Automatic Dependent Surveillance-Broadcast (ADS-B) Out Equipment, at

https://www.federalregister.gov/). Operators are encouraged to review the notice,

summarized below.

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4.3.4.1 To operate in ADS-B airspace, an operator whose aircraft is not equipped with

ADS-B Out equipment must obtain a preflight authorization in accordance

with § 91.225(g). The operator has the responsibility to obtain a preflight

authorization from ATC for all ADS-B Out airspace on the planned flight

path. For the reasons explained in the policy, however, the FAA will be very

unlikely to issue routine and regular authorizations to scheduled operators

seeking to operate non-equipped aircraft in rule airspace. Likewise, although

unscheduled operators may request authorizations for airspace at capacity

constrained airports as defined in the policy, issuance of an authorization may

prove difficult to obtain.

4.3.4.2 Note that the provision of air traffic services to a non-ADS-B-equipped

aircraft whose flight transits ADS-B Out airspace will not constitute

authorization under § 91.225(g). Although ATC will be able to observe that an

aircraft is not equipped with ADS-B Out equipment, ATC will not be

responsible for determining whether non-equipped aircraft operating in the

NAS are properly authorized to operate in ADS-B Out airspace. The provision

of air traffic services is separate from and will not constitute an authorization

to deviate from the ADS-B Out equipage requirements while operating in that

airspace. The non-equipped operator, as always, will have the responsibility to

ensure compliance with the regulations, which includes obtaining a preflight

authorization in accordance with § 91.225(g).

4.3.5 ADAPT. The FAA is developing a web-based mechanism for requesting authorization in

accordance with the regulation and this policy. You may access ADAPT at

https://sapt.faa.gov/. While ADAPT is intended primarily for requests to operate without

ADS-B, you may also choose to use it as a means to request an authorization to operate

with inoperative ADS-B. Operators who coordinate certain operations with an FAA TCA

should continue to make requests through the TCA. Refer to the ADAPT User Guide for

additional information.

4.4 Flight Plans (FP). The information to complete the ICAO FP continues to evolve with

the introduction of NextGen equipment and capabilities. The information provided here

represents just some of the ADS-B specific information elements. For the most current

and complete instructions and descriptions of FP filing codes, refer to AIM

paragraph 5-1-9 and the FAA Flight Planning Information website at http://www.faa.gov/

about/office_org/headquarters_offices/ato/service_units/enroute/flight_plan_filing.

4.4.1 ICAO FP Item 10, Equipment. When operating aircraft equipped with ADS-B you should

indicate surveillance equipment in Item 10 of the ICAO FP (FAA Form 7233-4, Pre-

Flight Pilot Checklist and International Flight Plan). In addition to the transponder codes

(refer to AIM paragraph 5-1-9), you should include an ADS-B capability code from the

following list. Note that FAA automation does not process ADS-B reports on Very High

Frequency (VHF) Digital Link Mode 4, so those codes are not listed here.

4.4.2 ADS-B Capability Codes. The ADS-B capability codes are as follows:

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4-9

• B1: ADS-B with dedicated 1090 megahertz (MHz) ADS-B Out capability.

• B2: ADS-B with dedicated 1090 MHz ADS-B Out and In capability.

• U1: ADS-B Out capability using UAT.

• U2: ADS-B Out and In capability using UAT.

Note 1: Only include an ADS-B capability code when at least one serviceable

ADS-B Out system is installed.

Note 2: Do not file an ADS-B code for “in” capability only. There is currently

no way to indicate that an aircraft has “in” capability but no “out” capability. For

aircraft with ADS-B “out” on one frequency and “in” on another, include only the

ADS-B “out” code. For example, B1 or U1.

4.4.3 ICAO FP Item 18, Other Information.

4.4.3.1 SUR/260B: If you file an ADS-B capability code of B1or B2 in Item 10 and

the ADS-B equipment complies with § 91.225, include the item “SUR/260B”

in Item 18.

4.4.3.2 SUR/282B: If you file an ADS-B capability code of U1 or U2 in Item 10 and

the ADS-B equipment complies with § 91.225, include the item “SUR/282B”

in Item 18.

Note: If the ADS-B capability filed in Item 10 is not compliant with

§ 91.225, do not include “SUR/” information in this FP field.

4.4.3.3 CODE/: After CODE/, enter the aircraft address expressed in the form of six

hexadecimal characters (e.g., “CODE/A519D9”). Operators of U.S. registered

aircraft can retrieve this information from the FAA aircraft registry

(https://registry.faa.gov/aircraftinquiry/NNum_Inquiry.aspx). Use the

“Mode S Code (base 16 / hex)” value.

4.4.3.4 REG/: When you enter an aircraft identification in Item 7 that is different than

the aircraft registration mark (e.g., “UAL123”), include REG/ symbol

followed by the registration markings of the aircraft, (e.g., “N123UA”) in

Item 18.

4.4.4 Anonymity Operations and VFR FPs. Section 91.227 contains specific provisions

allowing operators with TSO-C154c equipment to transmit a self-assigned (randomized)

temporary 24-bit address and no call sign. However, pursuant to the regulations

(§ 91.227(d)(11)), the UAT anonymous 24-bit address feature may only be used when the

operator “has not filed a flight plan” and “has not requested ATC services.” In 2018, the

Aircraft Owners and Pilots Association (AOPA) petitioned the FAA for a limited

exemption from a portion of § 91.227(d)(8) and (11). Specifically, AOPA sought an

exemption to permit pilots to operate using anonymous mode when the pilot has filed a

VFR FP and has not requested ATC services. Rather than granting the exemption, the

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FAA clarified that it interprets the exceptions in § 91.227(d)(8) and (11) as applying to

pilots who: (1) have not filed an instrument flight rules (IFR) FP; (2) have not requested

ATC services, such as separation services or VFR flight following; and (3) are using a

TSO-C154c self-assigned temporary 24-bit address. As a result, VFR pilots using the

anonymity feature may file a VFR FP, which enables search-and-rescue capabilities,

provided they do not request flight following.

Note: For any operation where ATC assigns you a discrete Mode 3/A code, you

are receiving ATC services.

4.4.5 Privacy ICAO Address (PIA) Program. The FAA acknowledges the desire of some

operators to limit the availability of real-time ADS-B position and identification

information for a specific aircraft. To address privacy concerns and to accommodate the

needs of aircraft, participation will be subject to the following conditions and limitations:

• U.S. registered.

• 1090 MHz ADS-B equipped.

• Using a third-party call sign.

• Flying in domestic U.S. airspace.

4.4.5.1 The PIA program will enable interested aircraft owners to request an alternate,

temporary ICAO aircraft address, which will not be assigned to any owner in

the Civil Aviation Registry (CAR). This service will be available in two

phases:

1. Phase 1: No later than January 1, 2020, the application for PIA can be

accessed on the FAA website at

https://www.faa.gov/nextgen/equipadsb/privacy/. This service will be

operated, monitored, and maintained by the FAA.

2. Phase 2: The service will be transitioned to third-party service provider(s)

who will operate, monitor, and maintain this program, which will continue

to be available from the above website.

4.4.5.2 To maintain the safety and integrity of air traffic operations, the FAA

monitors PIA use in the NAS. The following list includes improper uses of

PIAs:

• Use of PIAs assigned to another aircraft.

• Use of unassigned PIAs.

• PIAs used for operations outside of domestic airspace.

• PIAs changed in flight.

• PIAs used with an underperforming ADS-B emitter.

• PIA used with a UAT or dual 1090/UAT emitter.

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4.4.5.3 PIAs used by an aircraft other than the aircraft to which the address is

assigned results is a violation of § 91.227 and notification to the FAA. Upon

detection of improper PIA use, the aircraft owner/operator will be issued a

warning that requires immediate action to remedy the issue before the next

operation involving the assigned PIA. Failure to comply may result in the

revocation of the PIA assignment. Upon revocation of the PIA assignment, the

aircraft would be required to fly with its original ICAO aircraft address as

found in the CAR, and failure to do so would result in regulatory enforcement

action by the FAA and cessation of additional PIA assignments to that aircraft

until the enforcement action is closed.

4.4.5.4 An aircraft operator may use the ICAO aircraft address originally assigned

and recorded in the CAR at any time for operations, including any time while

having an active PIA assignment. Use of the assigned ICAO aircraft address

recorded in the CAR is required for all flights leaving U.S. sovereign airspace,

and it may be used for any other flights at any time, as desired by the aircraft

operator.

4.4.5.5 The FAA requires that the user submits documented validation that an ICAO

code has been correctly installed into the aircraft’s ADS-B avionics after each

change. Refer to the FAA PIA website for complete program details.

4.5 Preflight Requirements (U.S. Airspace).

Note: The remainder of paragraph 4.5 describes additional preflight

considerations that do not apply to the operation of aircraft equipped with

Satellite-Based Augmentation System (SBAS)/Aircraft-Based Augmentation

System (ABAS) position sources, as further described in paragraphs 4.5.1.4

and 4.5.1.5.

4.5.1 Flight Planning Requirements for Certain Operators. Under § 91.103, pilots and operators

must use all available information in planning their flight, to ensure that the performance

requirements will be met for the duration of the flight. Variations in position source

performance affect ADS-B Out in two specific broadcast elements required by

§ 91.227—Navigation Accuracy Category for Position (NACp) and Navigation Integrity

Category (NIC). During certain Global Positioning System (GPS) constellation

geometries, some position sources may produce values for NACp and NIC that are less

than required by the rule.

4.5.1.1 Four different variants of GPS receivers are currently in use as a position

source that can meet ADS-B Out rule performance requirements, to varying

degrees, when adequate numbers of GPS satellites are in view. Selective

availability (SA) is a feature that deliberately degraded the GPS satellite

signal, resulting in a less accurate reported position. SA was deactivated

in 2000.

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4.5.1.2 SA-On GPS receivers assume SA is still active (on), thereby unnecessarily

inflating integrity and accuracy bounds of the positions that are no longer

degraded by SA. Most GPS receivers that are only compliant with TSO-C129,

Airborne Supplemental Navigation Equipment Using the Global Positioning

System (GPS), are SA-On receivers.

4.5.1.3 SA-Aware GPS receivers are designed to recognize that SA is inactive and

optimize the performance from GPS. GPS receivers that comply with the

performance requirements of TSO-C196, Airborne Supplemental Navigation

Sensors for Global Positioning System Equipment using Aircraft-Based

Augmentation, are SA-Aware receivers.

4.5.1.4 SBAS receivers also use the additional signals from geostationary satellites

specifically designed for aviation use, improving the quality and robustness of

positioning performance. This difference in performance is most pronounced

for very precise operations, such as localizer performance with vertical

guidance (LPV) approaches, and for all operations when there are inoperative

GPS satellites. GPS receivers complying with TSO-C145, Airborne

Navigation Sensors Using the Global Positioning System Augmented by the

Satellite Based Augmentation System (SBAS), or TSO-C146, Stand-Alone

Airborne Navigation Equipment Using the Global Positioning System

Augmented by the Satellite Based Augmentation System (SBAS), are SBAS

receivers.

4.5.1.5 ABAS sensors tightly integrate GPS measurements with inertial

reference/navigation sensor data, improving the quality and robustness of

positioning performance. This difference in performance is most pronounced

for lower level Required Navigation Performance (RNP) operations, such as

Area Navigation (RNAV) approaches, and for all operations when there are

inoperative GPS satellites.

Note 1. Some GPS receivers manufactured with a TSO-C129a

approval are SA-Aware, and, therefore, have the same NACp and NIC

availability as TSO-C196() approved equipment. Operators should

check with their GPS receiver supplier to verify whether their installed

TSO-C129() GPS receiver is SA-On or SA-Aware.

Note 2. The wide area augmentation system (WAAS) is the

designation of the SBAS system available in North America and is the

term often used when making reference to SBAS in the United States.

4.5.2 GPS Performance Prediction. For aircraft equipped with TSO-C129() or TSO-C196()

GPS units to support ADS-B Out equipment, an NACp and NIC GPS service availability

prediction should be performed for the intended route of flight (route and time) using

available GPS satellite information and guidance published in this AC. It is not necessary

for operators of aircraft equipped with the WAAS (TSO-C145 or TSO-C146) receivers to

conduct a preflight availability prediction. Operators of aircraft equipped with specific

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ABAS receivers that have been reviewed by the FAA, are approved for ADS-B

operations (i.e., §§ 91.225 and 91.227), and have demonstrated sufficient performance do

not need to conduct a preflight availability prediction. For operations under

Exemption 12555, see paragraph 4.5.3 for additional guidance. See Table 4-1, Preflight

Availability Prediction, for a summary.

Note: Operators should check with their ABAS receiver supplier and/or airplane

manufacturer to verify whether their installed ABAS receiver has been reviewed

and approved by the FAA for operation without need to conduct a preflight

availability prediction.

4.5.2.1 Prediction Methods. Operators may use any of the following preflight

availability prediction methods.

4.5.2.1.1 Operators of large fleets of aircraft or users of flight planning programs may

wish to use their own preflight availability verification tool. The operator is

responsible for selecting a tool that accurately predicts the ADS-B position

source performance for their aircraft. The tool needs to account for the GPS

satellites that are in service at the time of the prediction, and may take into

account unique characteristics of the GNSS receiver, aircraft integration, or

installation; including performance better than required in FAA standards or

use of inertial information integrated into the ADS-B Out position source. The

FAA does not evaluate or approve a particular tool, but may evaluate the basis

of the operator’s determination that the tool is appropriate to their aircraft,

particularly if its use results in noncompliant flights in airspace where ADS-B

Out is required.

4.5.2.1.2 Operators may use the FAA-provided preflight availability prediction tool,

called the Service Availability Prediction Tool (SAPT) (http://sapt.faa.gov).

Refer to the SAPT User Guide for specific instructions on its use.

4.5.2.1.3 Operators may use a third-party interface, incorporating FAA GPS

performance prediction data without altering performance values, to predict

NACp/NIC performance outages for the aircraft’s predicted flightpath and

times.

4.5.2.2 Prediction Model Parameters. The operator should use a model appropriate

to their equipment, including the type of GPS receiver and the demonstrated

capability to track satellites at a given mask angle. When selecting a mask

angle, the operator should consider the equipment qualification, installation in

the aircraft, and the effects of normal maneuvering. Aircraft are typically

qualified with a five-degree mask angle, and operational experience has

indicated that a two-degree mask angle can be achieved by some equipment

installations. If using the SAPT, each prediction is valid for the operation

within 5 minutes of the plan time and 7.5 nautical miles (NM) of the route.

The operator may wish to submit additional requests for predictions for

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varying times around the proposed departure time to ensure compliance at the

actual departure time.

4.5.2.3 Flight Planning Guidance. Predictions should be conducted within 24 hours

of departure and as close to departure time as feasible, but with sufficient time

to re-plan the flight in the event a segment along the planned route is predicted

to have insufficient GPS service availability. The prediction should be

re-evaluated prior to flight if new information (i.e., a Notice to Airmen

(NOTAM)) provides notice of an unscheduled GPS satellite outage. In the

event of a predicted loss of performance for any part along the intended route

in the airspace where ADS-B Out is required, the flight should be re-planned

so that ADS-B Out performance requirements specified in § 91.227 can be

met.

Table 4-1. Preflight Availability Prediction

Preflight availability prediction?

Equipment

Years 2020-2024

After 2024

Exemption 12555

No Exemption

SA-On

Yes

SAPT will determine

backup surveillance and

exemption authorizes

flight if prediction results

in NIC < 7 and/or

NACp < 8.

Yes

If prediction results in

NIC < 7 and/or

NACp < 8, operator

should re-plan the flight

or request ATC

authorization.

Yes

If prediction results in

NIC < 7 and/or

NACp < 8, operator

should re-plan the flight

or request ATC

authorization.

SA-Aware

Exemption authorizes

flight without the need for

preflight prediction.

Yes

If prediction results in

NIC < 7 and/or

NACp < 8, operator

should re-plan the flight

or request ATC

authorization.

Yes

If prediction results in

NIC < 7 and/or

NACp < 8, operator

should re-plan the flight

or request ATC

authorization.

SBAS/ABAS No No No

4.5.3 Operations Conducted Under Exemption No. 12555. In August 2015, the Administrator

issued Exemption No. 12555, a time-limited grant of exemption from § 91.227(c)(1)(i)

and (iii) for the period from January 1, 2020 through December 31, 2024 to operators

who made timely notification of intent to comply with the conditions and limitations.

Those operators approved to conduct operations under the conditions and limitations of

Exemption No. 12555, or a similar exemption as determined by the FAA, should adhere

to the additional guidance provided in this section.

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Note: Operators approved to operate under Exemption No. 12555 are encouraged

to review the conditions and limitations detailed in the Grant of Exemption

No. 12555 at Docket Number FAA-2015-0971, Petition for Exemption, at

https://www.regulations.gov/.

4.5.3.1 Under the conditions of Exemption No. 12555, operators with receivers

meeting the performance requirements of TSO-C196() may operate in

designated airspace for which ADS-B Out is required when the aircraft’s

NACp and NIC do not meet the performance specified in § 91.227. For these

operations, the operator does not need to conduct any preflight availability

prediction.

4.5.3.2 Operators conducting operations under Exemption No. 12555 using

TSO-C129-approved GPS receivers that do not meet the performance

requirements of TSO-C196, TSO-C145, or TSO-C146 may operate in

airspace where ADS-B Out is required when the aircraft’s NACp and NIC do

not meet the performance specified in § 91.227, when the FAA determines

that backup surveillance is available. SAPT will indicate if the FAA has

determined that backup surveillance is predicted to be available during a

predicted performance outage. Since the FAA must make the determination

that backup surveillance is predicted to be available, the SAPT is the only tool

that can provide this capability. The applicable SAPT run should be

completed no more than 3 hours before the planned departure time. If ATC in

the departure jurisdiction requires FP submission earlier than 3 hours prior,

the SAPT for backup surveillance should be run just prior to FP submission.

Under Exemption No. 12555, operators may elect to use their own tool for

preflight prediction and use SAPT only to determine the availability of backup

surveillance when needed under Exemption No. 12555.

4.5.4 Preflight Prediction Compliance. Operators need to perform an ADS-B Out preflight

prediction only for the intended route of flight to the intended destination. For example,

when departure and/or arrival alternate airports are required, no preflight prediction is

necessary for these routes. However, if you become aware of a change that could result in

degraded ADS-B Out performance, such as a satellite outage prior to receiving an ATC

clearance for the intended route of flight, then you should conduct a subsequent preflight

prediction for the planned flight. This will ensure that ADS-B Out performance is still

predicted to comply with the performance requirements of § 91.227(c)(1)(i) and (iii).

Once the pilot has received an ATC route clearance, there is no requirement to conduct a

subsequent preflight prediction. Therefore, upon receiving a satisfactory preflight

availability prediction and an ATC clearance for an intended route of flight, the operator

will be deemed to have complied with the preflight availability prediction requirement

and the performance requirements of § 91.227(c)(1)(i) and (iii). The FAA accepts that

unanticipated changes in route of flight and environmental conditions may adversely

affect ADS-B Out performance. ATC will continue to exercise its responsibility for the

safe and efficient movement of air traffic, including the routing of traffic to meet those

objectives. ADS-B preflight planning should include:

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4-16

• Identification of flights or aircraft that require completion of a preflight prediction.

• Identify the preflight prediction system (or systems) to be used.

• Include a means to document completion of a satisfactory prediction for each flight

where a prediction is required.

• Retain documentation of prediction completion for a suitable period of time, such as

three months.

4.5.5 GPS Interference with ADS-B Compliance. There may be times when the GPS position

source cannot meet the required technical performance for compliance with § 91.227 due

to planned GPS interference. In the event of a scheduled interference outage of GPS, the

FAA will issue a NOTAM that identifies the airspace and time periods that may be

affected by the interference. The FAA has determined that it would be impractical and

not in the public interest to require operators to avoid the affected area based on the

chance that an otherwise compliant flight could experience GPS interference.

Accordingly, operators should proceed with their intended operation if the only

impediment to their operation is possible planned GPS interference. An operator who is

required to perform a preflight availability prediction for the intended route of flight is

still required to obtain a satisfactory preflight availability prediction. When a NOTAM

identifies the airspace and time periods that may be affected by GPS interference, an

operator will not be required to alter his or her route of flight to avoid the area based

solely on that NOTAM. If an operator encounters actual GPS interference during their

flight that results in a degradation of ADS-B Out performance, provided the operator has

taken the appropriate preflight actions, the FAA will not consider these events to

constitute a violation, as such application of the regulation would impose standard of

conduct wholly outside the operator’s control.

4.5.6 SAPT Outages. The FAA will issue a NOTAM in the event of a SAPT outage. Operators

who use SAPT as their preflight prediction tool will not need to conduct a preflight

prediction for the duration of the outage. Additionally, any flight plans submitted to ATC

with a proposed departure time within 90 minutes of SAPT return to service do not

require a subsequent preflight analysis. When there is a SAPT outage and an operation

falls below the performance requirements, provided the operator has taken the

appropriate preflight actions with regard to relying upon SAPT, the FAA will not

consider these events to constitute a violation, as such application of the regulation would

impose standard of conduct wholly outside the operator’s control. For operators who

have been notified by the FAA of consistent and repeated ADS-B Out performance

issues, the FAA cautions that operating during a SAPT outage without first redressing the

identified non-performance issue will be considered a continuation of existing

noncompliance of the performance requirements.

4.6 Flightcrew Entry of Required ADS-B Data. The operator should develop operational

procedures to address flightcrew entry of the ADS-B message elements required in

§ 91.227 and as described in paragraphs 4.6.1 through 4.6.4. If the ADS-B avionics

system design does not allow for a single point of entry for this information, the AFM,

AFMS, RFM, RFMS, POH, or other required flight manual must address the requirement

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4-17

to enter the information multiple times through the appropriate system’s interface and to

ensure that conflicting ACID information is not transmitted to ATC.

4.6.1 Mode A Code.

4.6.1.1 ATC automation relies on the Mode A code to identify aircraft under radar

surveillance and to correlate the displayed target to an FP. The Mode A code

is one element of the transmitted ADS-B message set. Since SSR and ADS-B

surveillance will overlap in much of the NAS, correlation of the Mode A code

between the transponder and the ADS-B message is necessary to ensure that a

single target is resolved and correlated to an FP route.

4.6.1.2 It is imperative that the ATC-assigned transponder code is identical to the one

in the ADS-B Out message. A preferable design configuration is one that

provides the pilot a single point of entry for the Mode A code in both the

transponder and the ADS-B Out avionics. If there is no single point of entry

provided for the Mode A code into the transponder, then the AFM or

operating handbook must address the requirement to enter the Mode A code

into both systems separately.

Note: Transmission of conflicting transponder and ADS-B Mode A

codes will result in erroneous traffic conflict alerts within the ATC

automation system.

4.6.2 Aircraft’s Flight Identification (FLT ID).

4.6.2.1 An aircraft’s FLT ID is transmitted by the ADS-B Out avionics. The FLT ID

is composed of a maximum of seven alphanumeric characters and, per

§ 91.227(d)(8), must be identical to the “Aircraft Identification” as entered in

Item 7 of the FP. It is also referred to as a call sign. The FLT ID is typically

entered by the flightcrew during preflight through either a flight management

system (FMS) interface (control display unit (CDU)) or transponder control

panel. The FLT ID for General Aviation (GA) aircraft is typically associated

with the aircraft’s registration number. The aircraft owner can preset the

FLT ID to the aircraft’s registration number (e.g., N235RA), since it is a fixed

value, or the pilot can enter it into the ADS-B Out system prior to flight,

provided the ADS-B avionics has this capability. It is important to know that

the FLT ID should be input into the ADS-B system exactly as filed in block 2

or Item 7 of the FP. No additional characters should be used to fill all

available fields.

4.6.2.2 Some ATC systems use transmitted FLT IDs to uniquely identify each aircraft

within a given airspace and correlate them with a filed FP for the provision of

surveillance and separation services. If the FLT ID is not entered correctly,

ATC automation systems may not associate surveillance tracks for the aircraft

to its filed FP. Therefore, air traffic services may be delayed or unavailable

until this is corrected. Consequently, it is imperative that flightcrews and GA

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4-18

pilots ensure the FLT ID entry correctly matches the ACID annotated in the

filed ATC FP prior to departure.

4.6.2.3 In FAA ATC systems, if the FLT ID transmitted by the aircraft’s ADS-B

system does not exactly match the FLT ID on the FP, a call sign mismatch

(CSMM) occurs. When a CSMM occurs, the controller is alerted and may

take action resulting in a flight delay. Furthermore, ATC may elect to advise

the Flight Standards Service of the event and the potential violation of

§ 91.227(d)(8). The specific wording of this regulation has caused

misunderstanding from numerous operators and airmen who believe it is

acceptable to have a different FLT ID on the FP [ABC1234] from the

FLT ID [N12345] transmitted by ADS-B. In an August 3, 2017 legal

interpretation, the FAA Office of the Chief Counsel found that the intent of

§ 91.227(d)(8) is to require that the FLT ID as entered on the FP must exactly

match the ADS-B transmitted FLT ID. See Table 4-2, Aircraft Identification

Transmission Examples, for examples.

Table 4-2. Aircraft Identification Transmission Examples

Flight Plan Aircraft ID

Correct ADS-B Transmission

Incorrect ADS-B Transmission

AAL5688

AAL-5688

SWA2155

2155

UAL21

UAL0021

DAL9450

N561DL

ASH5861

ASH5872

N350QS

EJA350

FDY1055

VFR

N777JK

N-777JK

N123DJ

NGF123

CGABC

C-GABC

VHXYZ

VH-XYZ

4.6.2.4 GA pilots occasionally have the opportunity to use a FLT ID provided by a

charity or other organization instead of using their N-number. In this situation,

the GA pilot may only use the organization’s FLT ID for the flight provided

they change the FLT ID transmitted by the ADS-B Out avionics. If the

ADS-B equipment does not allow the FLT ID to be changed or the pilot is

unsure of how it is accomplished, the pilot should not use the organization’s

FLT ID. In this case, in order to ensure compliance with § 91.227(d)(8), the

pilot should use the aircraft registration number as the FLT ID.

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4-19

4.6.3 Emergency Status.

4.6.3.1 This ADS-B message element and transponder code alerts ATC that the

aircraft is experiencing emergency conditions and indicates the type of

emergency. The appropriate Mode A code should be entered into the

transponder (e.g., 7500, 7600, or 7700). The ICAO Annex 10, Volume IV,

Surveillance and Collision Avoidance Systems, emergency codes (general

emergency, no communications, and unlawful interference) are required by

§ 91.227.

4.6.3.2 ADS-B systems integrated within a transponder will automatically set the

applicable emergency status when code 7500, 7600, or 7700 is entered into

the transponder.

4.6.3.3 ADS-B systems not integrated with the transponder or systems with optional

emergency codes may need the appropriate emergency code to be entered

through a separate pilot interface. Flightcrews should ensure that both

emergency codes (ADS-B and transponder) are identical.

4.6.4 Transponder IDENT Function. The AFM or POH will provide specific instructions on

how the IDENT feature will be activated in specific installations, including any

installations with multiple IDENT features.

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Appendix A

A-1

APPENDIX A. ADS-B IN-TRAIL PROCEDURE

A.1 Purpose. This appendix provides a description of the ADS-B-enabled In-Trail Procedure

(ITP) and guidance to operators seeking FAA authorization to conduct ITP operations.

A.2 Background. The ITP is designed primarily for use in nonradar oceanic airspace to

enable appropriately equipped ADS-B In aircraft to perform flight level (FL) changes

previously unavailable with procedural separation minima applied. The improved traffic

information available to ADS-B In-equipped aircraft allows ITP maneuvers to occur

safely with reduced separation minima applied. ITP enables flightcrews to execute FL

changes to improve ride comfort, avoid weather, or obtain more favorable winds to

improve fuel economy and arrival times.

A.2.1 ITP Scenario. Figure A-1, Reduction of Aircraft Separation Minima with In-Trail

Procedure, illustrates a basic ITP scenario. The ITP aircraft (blue) wishes to climb from

FL340 to 360 between two reference aircraft (red) where procedural separation minima is

applied. Using onboard ADS-B In and ITP equipment, the ITP aircraft can determine if

the necessary criteria can be met and, if so, request air traffic control (ATC) approval to

execute the desired FL change using reduced separation minima between the two

reference aircraft.

A.2.2 ATC Responsibility. ATC maintains separation responsibility throughout the ITP

maneuver, and resumes the appropriate separation minima at its completion. ATC will

apply the reduced ITP separation only between a qualified ITP aircraft and no more than

two reference aircraft for the duration of the maneuver. The ITP maneuver can be

performed with reference aircraft that do not have ADS-B In equipment. To enable an

ITP maneuver, it is necessary for the reference aircraft to transmit an ADS-B Out signal

of sufficient quality.

Figure A-1. Reduction of Aircraft Separation Minima with In-Trail Procedure

A.3 ITP Terminology.

A.3.1 Closing Groundspeed (GS) Differential. The difference between the ITP aircraft’s GS

and a reference aircraft’s GS that results in a reduction of the ITP distance.

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Appendix A

A-2

A.3.2 Closing Mach Speed Differential. The difference in Mach speed between the ITP aircraft

and the reference aircraft that results in a reduction of the ITP distance.

A.3.3 ITP Aircraft. An aircraft operated by a flightcrew authorized to conduct an ITP.

A.3.4 ITP Criteria. A set of conditions to be satisfied prior to initiating or executing an ITP

clearance that ensure the safety of the procedure.

A.3.5 ITP Distance. The distance between the ITP aircraft and reference aircraft as defined by

the difference in distance to an aircraft calculated common point along a projection of

each aircraft’s track in front of or behind the aircraft, as appropriate. (See Figure A-2,

In-Trail Procedure Distances Illustrated.) For the case where aircraft are on parallel

tracks, the ITP distance is measured along the track of one of the aircraft using its

calculated position and the point abeam the calculated position of the other aircraft. This

measurement technique is similar to the method described in the International Civil

Aviation Organization (ICAO) Doc 4444, Procedures for Air Navigation Services—Air

Traffic Management, Section 5.4.2.9, Performance-Based Longitudinal Separation

Minima.

A.3.6 ITP Equipment. The onboard avionics that support an ITP.

A.3.7 Reference Aircraft. Aircraft (no more than two) transmitting valid ADS-B data that meet

specified criteria and are referenced as part of an ITP clearance request to ATC.

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Appendix A

A-3

Figure A-2. In-Trail Procedure Distances Illustrated

A.4 ITP Concept. The ITP concept is based on the aircraft satisfying specific initial

conditions and the flightcrew promptly and correctly executing the requested procedure

once approved. The initial conditions are the ITP speed/distance criteria, the relative

altitude criteria, the similar track criteria, and the closing Mach differential, as well as the

accuracy and integrity of the ADS-B data transmitted from participating aircraft. (See

Table A-1, In-Trail Procedure Initiation/Maneuver Criteria (Reference RTCA DO-312

Supplement).) The safety of the procedure depends upon the ITP aircraft maintaining

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Appendix A

A-4

constant Mach and climb or descend at a minimum of 300 feet per minute (fpm) during

the maneuver. With these criteria, an ITP aircraft should never come closer than the

10-nautical-mile (NM) separation minimum to a reference aircraft while passing through

their altitude(s).

A.4.1 ITP Distance and GS Differential Criteria. The initial distance criteria values, 15 NM and

20 NM, were selected so that when an FL change at 300 fpm and constant Mach number

is maintained with the respective maximum 20 or 30-knot (kts) closing GS differential,

the distance between the aircraft should not become less than the ITP minimum

separation of 10 NM.

A.4.2 Relative Altitude Criteria. The design of the procedure is such that the reference aircraft

may not be more than 2,000 feet above or below the ITP aircraft.

A.4.3 Similar Track Criteria. Application of the ITP is limited to geometries where the ITP

aircraft and any reference aircraft are on similar tracks. Similar tracks are defined here as

less than 45 degrees from one another. See Figure A-3, Similar Track.

Figure A-3. Similar Track

A.4.4 Mach Differential. In order to ensure an acceptable closure throughout the ITP maneuver,

the controller will not issue an ITP clearance if the closing Mach differential is greater

than 0.06 Mach. This Mach differential check accounts for potentially unsafe closure

rates due to abnormal or adverse wind gradient conditions at the intermediate altitudes.

The Mach number check may be achieved by:

1. Using the cruise Mach numbers of the ITP and reference aircraft where the Mach

number technique is being used;

2. Requesting Mach numbers from the ITP and reference aircraft; or

3. Any other methodology determined appropriate and acceptable by the regulatory

authority and the air navigation service provider (ANSP).

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Appendix A

A-5

A.4.5 ADS-B Data Quality Criteria. The ITP avionics only accept ADS-B Out aircraft

broadcasting data of sufficient quality for use as reference aircraft for ITP. The ITP

avionics only allow ITP when own-ship data quality are sufficient to ensure safe

separation. The data quality criteria are:

1. Position accuracy for ITP and reference aircraft—ITP and reference aircraft data with

horizontal position accuracies of at least 0.5 NM (95 percent);

2. Position integrity for ITP and reference aircraft—ITP and reference aircraft data with

horizontal position integrity bounds of 1.0 NM at 1x10E-05; and

3. Velocity accuracy for ITP and reference aircraft—ITP and reference aircraft data with

horizontal velocity accuracies of at least 10 meters/second (m/s) (19.4 kts),

95 percent.

A.5 ITP Description. To properly conduct an ITP, a qualified flightcrew uses ADS-B In

avionics specifically certified to assist in verifying the initial conditions and a graphical

display to monitor the relative position(s) of nearby aircraft. The procedure can only be

conducted in airspace with appropriately trained ATC personnel, ITP compatible

automation, and approved ITP separation minima available. The following are the steps

necessary to conduct an ITP:

A.5.1 Flightcrew Verifies Initial Criteria. Using approved avionics, the ITP flightcrew verifies

that their own-ship and the reference aircraft meet initial qualifying criteria. The onboard

ITP avionics indicate to the flightcrew whether all initiation criteria are satisfied.

A.5.2 Flightcrew Requests ITP. If the criteria are satisfied, the flightcrew requests the ITP

clearance using the appropriate phraseology. Direct Controller Pilot Communication

(DCPC) ensures unambiguous communication of the ITP request and ATC clearance.

Currently, only Controller-Pilot Data Link Communication (CPDLC) is being used in

locations where ITP are approved. Preformatted messages for requesting and approving

ITP have not yet been developed. Flightcrews use standardized free text messages as

described in Table A-2, Flightcrew Standardized Free Text Controller-Pilot Data Link

Communication Message Set for In-Trail Procedure, and Table A-3, Controller Free Text

Controller-Pilot Data Link Communication Message Set for In-Trail Procedure, until

further notice. It is essential that the correct message elements be included in the correct

format to allow the controller or automation system to properly evaluate the request.

Improperly formatted or incomplete requests may be unnecessarily denied.

Note: ATC will not issue an ITP clearance to any aircraft unless that aircraft has

initiated the request.

A.5.3 Controller Issues Clearance. Upon receipt of an ITP request, the controller:

1. Confirms the ITP aircraft and the reference aircraft are on the same track.

a. Same-track criteria are not the same as the similar-track criteria, which are

checked by the ITP aircraft flightcrew.

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Appendix A

A-6

b. Same-track includes the concept of similar-track (i.e., ITP aircraft and reference

aircraft are traveling in the same direction with less than a 45-degree relative track

angle between the aircraft), but also includes a check on whether or not the lateral

protection areas overlap (e.g., lateral separation cannot be applied). This check

can only be done by the controller who knows what separation standard is being

applied between the aircraft.

2. Confirms that no more than two reference aircraft have been identified in the request

and are identified correctly; that is, that the Aircraft Identification (ACID) of each

reference aircraft in the ITP request exactly matches the corresponding aircraft’s filed

flight plan (FP).

3. Ensures both the ITP aircraft and reference aircraft are not maneuvering and not

expected to maneuver during the ITP.

Note: A change of course (only) to remain on the same route would not be

considered a maneuver, provided the course change is less than 45 degrees and

the aircraft remain in a same track configuration.

4. Verifies that the closing Mach differential is no greater than 0.06 Mach.

5. Verifies that there are no conflicts at the requested altitude.

6. If appropriate, issues an ITP clearance.

A.5.4 Flightcrew Reassesses Criteria. Upon receiving the ITP clearance, the flightcrew

confirms that all criteria are still satisfied. If the criteria are not satisfied or there has been

a loss of traffic information, the flightcrew immediately rejects the ATC clearance and

terminates the maneuver. Additionally, if the FL, reference aircraft, or type of maneuver

(ITP versus standard FL change) does not exactly match their request or if the flightcrew

receives an ITP clearance without requesting one, they will not perform the maneuver

and should verify with ATC to confirm the clearance.

A.5.5 Flightcrew Executes ITP. If the criteria are still met, the flightcrew accepts the clearance

and begins the requested climb or descent without delay. While executing the maneuver,

the flightcrew is expected to maintain their flight-planned route, assigned Mach number

(or current Mach, if none is assigned), and minimum Vertical Speed (VS) of 300 fpm and

ensure they execute only the maneuver for which they have been cleared. The maneuver

is complete once the flightcrew reports to ATC that they have reached the new FL.

Note: Once the ITP maneuver has been initiated, it should be completed and the

aircraft not returned to the initial altitude. Should reference aircraft data be lost or

ITP display fail during the maneuver, the flightcrew should continue the

maneuver to the assigned altitude using the appropriate Mach number and 300

fpm minimum VS. Upon completion of the maneuver, notify ATC of the ITP data

loss.

A.5.6 Approved ITP Variations. An ITP can be conducted with a maximum of two reference

aircraft. The procedure design does not allow the reference aircraft to be more than

2,000 feet of altitude above or below the ITP aircraft, but there is no limit on the amount

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Appendix A

A-7

of altitude change the ITP aircraft may request. The reference aircraft both may be behind

or ahead of the ITP aircraft or one may be ahead and one behind. Figure A-4, In-Trail

Procedure Climb/Descent Variations, depicts the approved ITP variations.

Figure A-4. In-Trail Procedure Climb/Descent Variations

A.5.7 Contingency Procedures. The ITP maneuver has been extensively tested both in flight

and in computer simulations with consideration given to a variety of environmental and

aircraft performance factors. A temporary breach of the 10-NM ITP distance does not

constitute an inherently unsafe procedure and should not be the sole factor when

considering abandoning the procedure. No new contingency procedures are prescribed

for ITP. If, in the pilot’s judgment, the ITP maneuver (i.e., reaching the newly assigned

altitude) cannot be successfully completed once the climb or descent has been initiated,

he or she will:

1. Contact ATC and request an alternative clearance as soon as practicable given

flightcrew workload and flight conditions.

2. Inform ATC of any action the flightcrew is taking or requesting. Because of the many

variables, the CPDLC message should be in the “free text” format.

3. Comply with regional contingency procedures appropriate to the circumstances, or as

listed in ICAO Doc 4444, Section 15.2, Special Procedures for In-Flight

Contingencies in Oceanic Airspace.

A.5.8 ITP Distance. Except when one aircraft is directly in trail of another, the ITP distance is

not the same as the direct line distance between those two aircraft. (See paragraph A.3,

ITP Terminology, for the exact description and Figure A-2 for examples.) Since the ITP

software is designed to calculate and display ITP distance information, extensive training

on the subject is not necessary. However, it is important to emphasize that range and ITP

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Appendix A

A-8

distance are different. Consequently, a lack of understanding could lead the flightcrew to

misidentify the correct reference aircraft(s) when requesting an ITP clearance. Training

should include examples of the various ITP distance geometries depicted in Figure A-2.

A.5.8.1 Lateral Traffic Filters. Some ITP avionics incorporate a lateral traffic filter.

The function of the traffic filter is to eliminate any targets beyond a

predetermined lateral distance of own-ship’s track from consideration as a

potential reference aircraft. This is intended to prevent the flightcrew from

misidentifying incorrect reference aircraft during their ITP request. The filter

is most useful when in an organized track environment or where traffic may

be on a parallel user-preferred route. Incorrect use may result in unnecessarily

denied ITP requests. Training should include recommended technique for its

use.

A.5.8.2 ITP Initiation Criteria. Traffic displayed as an ADS-B In target might not be

presented as a valid ITP reference aircraft because it does not meet one or

more ITP initiation criteria. Some of the criteria, such as position accuracy,

are not displayed to the flightcrew. Training should include a discussion of the

initiation criteria, which criteria are known to the flightcrew, and examples of

when a displayed ADS-B In target is not an eligible ITP reference aircraft. See

Table A-1 for ITP initiation criteria.

A.6 Authorization to Conduct ITP. FAA authorization is required for all U.S. aircraft

operators to conduct ITP operations using ADS-B In (14 CFR part 119, § 119.49(a)(5)).

This appendix provides guidance to operators on the process for requesting issuance of

this authorization, including guidance on the documentation that should be submitted.

Note 1: For FAA authorization, refer to FAA Order 8900.1, Volume 3,

Chapter 18, Section 3, Operations Specification (OpSpec)/Management

Specification (MSpec)/Letter of Authorization (LOA) A354, Automatic

Dependent Surveillance-Broadcast (ADS-B) In-Trail Procedure (ITP).

Note 2: Operators may already hold other ADS-B In authorizations. There is no

need to submit documentation for an ITP authorization if that documentation has

already been submitted for previous ADS-B In authorizations. The ITP

application may include references to those duplicate documents instead.

A.6.1 Initial Request for Authorization. U.S. aircraft operators seeking to conduct ITP should

first contact their assigned FAA office to indicate their intent. At the time of the

operator’s initial request, the FAA will provide the operator with an ITP Application

Checklist, which should be completed with attached supporting documents.

A.6.2 Documentation to Submit With Formal Proposal.

A.6.2.1 Documentation Guidance. The following section provides general guidance

on the documentation required for submission of a formal ITP proposal. At

the discretion of the operator’s assigned principal inspector (PI), additional

information may be required based on any unique aspects of their specific

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Appendix A

A-9

operation. The operator must submit a letter of request for issuance of

authorization to the assigned PI. The letter of request should include the

following information:

• Type of aircraft (make, model, and series (M/M/S)).

• ADS-B equipment complies with Technical Standard Order (TSO)-C195a,

Avionics Supporting Automatic Dependent Surveillance-Broadcast

(ADS-B) Aircraft Surveillance Applications (ASA), or later, or as

approved for ITP by the Administrator.

• Installation complies with Advisory Circular (AC) 20-172, Airworthiness

Approval for ADS-B In Systems and Applications.

• Manufacturer’s name of the ADS-B In software.

• Proposed region(s) of operation (not applicable to 14 CFR part 91

operations).

Note: The guidance contained in paragraph A.6.2 will also be

annotated on the ITP Using ADS-B In Application Checklist provided

to the operator by the applicable FAA office.

A.6.2.2 Airplane Flight Manual (AFM) Compliance Documentation. Operators

submit documentation that demonstrates that their aircraft have an ADS-B In

system that meets the performance standards of TSO-C195a or later, or as

approved for ITP by the Administrator.

A.6.2.3 Proposed Operations Area. Authorizations to conduct ITP are limited to

specific regions of the world where the ANSP offers ITP and those procedures

are determined to be acceptable to the Administrator. Routes or airspace

where ITP may be authorized will be published in Aeronautical Information

Publications (AIP). Include in your request a description, by flight information

region (FIR) and ANSP, of the operational areas where you propose to

conduct ITP. If the operator holds an OpSpec/MSpec B050, Authorized Areas

of En Route Operations, Limitations, and Provisions, authorization, submit a

draft B050 paragraph that includes the operational areas where you propose to

conduct ITP, including applicable notes.

A.6.2.4 Operational Procedures. As applicable, company manuals should address

any ITP-specific guidance from the Air Traffic Service Provider of the

proposed region(s) of operation.

A.6.2.5 Operation Manuals and Checklists. The certificate holder/operator/program

manager (as applicable) should submit information (e.g., Airplane Operations

Manual (AOM) bulletin or equivalent) to the flightcrews describing ADS-B,

to include:

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Appendix A

A-10

• ITP system description;

• Normal procedures;

• En route procedures using ITP;

• Communications; and

• Non-normal or contingency procedures.

A.6.2.6 Maintenance. See Appendix C, ADS-B In Operations—Aircraft

Qualification and Maintenance, for applicable maintenance guidance.

A.6.2.7 Revision of Minimum Equipment List (MEL). See Appendix C for

guidance on the necessary MEL documents to be submitted for authorization

of ITP.

A.6.2.8 Pilot Training. Submit applicable portions of proposed ITP-specific pilot

training material and include a description of the methods used to conduct,

evaluate, and manage the training. The following contains the recommended

information to be included in pilot training material:

1. General understanding of ADS-B In operations (i.e., technology,

capabilities, and limitations).

2. ITP system operation, including:

• Normal procedures;

• Non-normal and/or contingency procedures;

• ITP flight planning considerations;

• ITP dispatch considerations (as applicable);

• MEL considerations (as applicable);

• ITP terminology, including proper formulation of a CPDLC ITP

request/clearance; and

• ITP equipment limitations.

3. Explanation of ITP distance as distinct from aircraft range, using select

scenario-based examples. See Figure A-2 for ITP distance geometries.

• ITP directly in trail of a reference aircraft;

• ITP aircraft on a crossing track of reference aircraft—diverging;

• ITP aircraft on a crossing track of reference aircraft—converging; and

• ITP aircraft on a parallel track of reference aircraft.

A.6.2.9 Dispatch/Flight Follower Training. Submit applicable portions of proposed

ITP-specific dispatch/flight planning training material to include any

appropriate updates to the dispatch operations manual, or equivalent, as well

12/30/19 AC 90-114B

Appendix A

A-11

as a description of the methods used to conduct, evaluate, and manage

training. The following contains the recommended information to be included

in dispatch/flight planning training material:

1. General understanding of ADS-B In operations;

2. Dispatch of aircraft with the ITP system unserviceable;

3. How flight planning codes are affected with ADS-B unserviceable;

4. Flight planning, fuel loading, and route change procedures associated with

ITP operations;

5. Equipment needed to conduct ITP; and

6. Approved ITP routes and airspace.

Note: Dispatch/flight follower training is not required for part 91

operations. However, as the pilot is responsible for flight planning, the

pilot should consider these items prior to flight.

Table A-1. In-Trail Procedure Initiation/Maneuver Criteria (Reference

RTCA DO-312 Supplement)

In-Trail Procedure (ITP)

Speed/Distance Criteria

ITP Distance ≥ 15 nautical miles (NM) and Closing

Groundspeed (GS) Differential ≤ 20 knots (kts)

ITP Distance ≥ 20 NM and Closing GS

Differential ≤ 30 kts

Relative Altitude Criteria

Difference in altitude between ITP and Reference

Aircraft is less than or equal to 2,000 feet

Similar Track Criteria

Difference in track angles between ITP and

Reference Aircraft is less than ± 45 degrees

Position Accuracy for ITP and

Reference Aircraft

ITP and Reference Aircraft data with horizontal

position accuracies of at least 0.5 NM (95%)

Position Integrity for ITP and

Reference Aircraft

ITP and Reference Aircraft data with horizontal

position integrity bounds of 1.0 NM at 1x10E-05

Velocity Accuracy for ITP and

Reference Aircraft

ITP and Reference Aircraft data with horizontal

velocity accuracies of at least 10 meters/second (m/s)

(19.4 kts), 95%

Closing Mach Differential

(Air Traffic Control (ATC)

Crosscheck)

Closing Mach Differential is less than or equal to

0.06 Mach

12/30/19 AC 90-114B

Appendix A

A-12

Table A-2. Flightcrew Standardized Free Text Controller-Pilot Data Link Communication

Message Set for In-Trail Procedure

In-Trail Procedure (ITP) Type

(number and relative position of

reference aircraft)

FREE TEXT Message Element Content

1 reference aircraft (ahead)

“ITP [Distance] BEHIND [Aircraft FLT ID]”

1 reference aircraft (behind)

“ITP [Distance] AHEAD OF [Aircraft FLT ID]”

2 reference aircraft (both ahead)

“ITP [Distance] BEHIND [Aircraft FLT ID] AND

[Distance] BEHIND [Aircraft FLT ID]”

2 reference aircraft (both behind)

“ITP [Distance] AHEAD OF [Aircraft FLT ID] AND

[Distance] AHEAD OF [Aircraft FLT ID]”

2 reference aircraft (one ahead and

one behind)

“ITP [Distance] BEHIND [Aircraft FLT ID] AND

[Distance] AHEAD OF [Aircraft FLT ID]”

To request an ITP climb or descent, the flightcrew will send a Controller-Pilot Data Link

Communication (CPDLC) REQUEST CLIMB TO [altitude] or REQUEST DESCENT TO

[altitude] message, as applicable, with the following verbiage added to FREE TEXT as listed in

Table A-2:

Example of ITP request message: REQUEST CLIMB TO FL360 ITP 25 NM BEHIND

SIA228 AND 21 NM AHEAD OF AFR008.

Note: This standardized free text message set will be used until an appropriate

message set is implemented.

12/30/19 AC 90-114B

Appendix A

A-13

Table A-3. Controller Free Text Controller-Pilot Data Link Communication Message

Set for In-Trail Procedure

In-Trail Procedure (ITP) Type

(number and relative position of

reference aircraft)

FREE TEXT Message Element Content

1 reference aircraft (ahead)

“ITP BEHIND [Aircraft FLT ID]”

1 reference aircraft (behind)

“ITP AHEAD OF [Aircraft FLT ID]”

2 reference aircraft (both ahead)

“ITP BEHIND [Aircraft FLT ID] AND BEHIND

[Aircraft FLT ID]”

2 reference aircraft (both behind)

“ITP AHEAD OF [Aircraft FLT ID] AND AHEAD OF

[Aircraft FLT ID]”

2 reference aircraft (one ahead and

one behind)

“ITP BEHIND [Aircraft FLT ID] AND AHEAD OF

[Aircraft FLT ID]”

To grant an ITP request, the controller will send an uplink message containing CLIMB TO AND

MAINTAIN [altitude] or DESCEND TO AND MAINTAIN [altitude] containing the text in

Table A-3:

Example of ITP clearance message: ITP BEHIND SIA228 AND AHEAD OF AFR008

CLIMB TO FL360 REPORT LEVEL FL360.

Note 1: The controller should never issue an ITP clearance unless one has been

requested by a flightcrew.

Note 2: This standardized free text message set will be used until an appropriate

message set is implemented.

12/30/19 AC 90-114B

Appendix B

B-1

APPENDIX B. CAVS USING ADS-B IN

B.1 Purpose. This appendix describes Cockpit Display of Traffic Information (CDTI)

Assisted Visual Separation (CAVS) and provides guidance to operators seeking FAA

authorization to conduct CAVS operations.

B.2 Background. When a flightcrew accepts responsibility to maintain visual separation

from another aircraft, they should maintain constant visual surveillance of that aircraft

and notify air traffic control (ATC) if they can no longer do so. Additionally, the

flightcrew accepts the responsibility for wake turbulence separation from that aircraft.

Though the weather must be visual meteorological conditions (VMC) pursuant to CAVS

authorization, other environmental conditions may prevent them from maintaining

constant visual surveillance of the traffic, such as when the traffic is landing toward a

rising or setting sun. Additionally, distances and closure rate to an aircraft directly ahead

can be difficult to judge, such that managing spacing and avoiding wake turbulence can

be difficult.

B.3 CAVS Concept. CAVS is an ADS-B In application that assists the flightcrew in

maintaining separation from ADS-B Out-equipped aircraft during visual separation.

Currently, CAVS authorization is only for the approach phase of flight when cleared by

ATC to maintain visual separation from specific traffic. Because of the accuracy and

integrity of displayed traffic on ADS-B In systems approved for CAVS, CAVS

information may be used as a substitute for continuous visual observation of

traffic-to-follow (TTF) under specified conditions. CAVS does not relieve the pilot of the

responsibility to see and avoid other aircraft. ATC maintains separation responsibility

from all other aircraft and for the orderly flow of traffic to the runway. Currently, there is

no new phraseology associated with CAVS and approved for the use of CAVS. ATC will

be unaware that a flightcrew is using CAVS. CDTI traffic information does not replace

any traffic advisories (TA) and/or Resolution Advisories (RA) provided by the aircraft’s

Traffic Alert and Collision Avoidance System (TCAS). RA response is still based on the

TCAS display and approved procedures.

B.4 CAVS Arrivals. Traffic information from the CDTI is used to augment out-the-window

(OTW) visual contact with an aircraft a flightcrew is assigned to follow. This will enable

them to accept separation responsibility from that aircraft. Once the flightcrew has

visually acquired and accepted a visual approach clearance behind TTF, the pilot may use

the lead aircraft traffic information on the CDTI as a means for maintaining separation

while performing a visual approach. As done today with a visual approach clearance, no

specific spacing assignments will be made by ATC. The procedure can be conducted

behind all aircraft weight categories.

B.5 CAVS Description. Flightcrews are reminded that CAVS is a visual separation

procedure. If at any time the traffic information provided by CAVS equipment becomes

unreliable, inoperative, or distracting, its use should be discontinued immediately.

12/30/19 AC 90-114B

Appendix B

B-2

Note 1: Although aircraft call signs are displayed on the CDTI, flightcrews

should not use the call sign or Aircraft Identification (ACID) (flight identification

(FLT ID)) of observed traffic in radio communications, as this could create

confusion for both ATC and flightcrews monitoring the frequency.

Note 2: Flightcrews are not relieved of their duty to see and avoid.

Note 3: CAVS is currently restricted to maintaining visual separation from

aircraft approaching the same landing runway.

B.5.1 CAVS Alerting. Installations compliant with Technical Standard Order (TSO)-C195b,

Avionics Supporting Automatic Dependent Surveillance-Broadcast (ADS-B) Aircraft

Surveillance Applications (ASA), or later, incorporate two alerting features: a caution

level minimum range alert and an advisory level selectable range indication.

B.5.1.1 The selectable range indication alert is used to advise the flightcrew that the

CAVS aircraft is at a predetermined range from the TTF. The range indication

is set in accordance with individual established company procedures and is

intended to assist the flightcrew in maintaining a safe distance from the TTF.

B.5.1.2 The caution level minimum range alert is activated when the range to the TTF

is less than 1.4 nautical miles (NM) or, in some installations, when the CAVS

system detects a predetermined excessive closure to the TTF. This alert cannot

be modified by the flightcrew and indicates that, due to uncertainty in the

ADS-B positions at such close ranges, the CDTI cannot safely be used to

determine the position of the TTF.

B.5.2 Normal Procedures. CAVS normal procedures are as follows:

1. ATC points out TTF to flightcrew of CAVS-equipped aircraft.

2. The CAVS flightcrew visually locates the traffic OTW and reports this to ATC.

3. ATC issues a clearance to “maintain visual separation” from the TTF.

4. If the TTF is broadcasting usable ADS-B Out information, the CAVS flightcrew

correlates the TTF as seen OTW, with the traffic symbol of the TTF aircraft displayed

on their aircraft’s CDTI and any information provided via ADS-B.

5. Once the flightcrew has correctly correlated the TTF on the CDTI, they designate the

TTF target on the CDTI and the avionics displays the distance and groundspeed (GS)

differential between TTF and own-ship. If CAVS is equipped with a selectable range

indication alert, the flightcrew may set it in accordance with company procedures if it

has not already been set.

6. Aided by this information, the CAVS flightcrew can more easily maintain visual

contact with the TTF and more precisely manage their spacing and closure.

12/30/19 AC 90-114B

Appendix B

B-3

7. The CAVS aircraft maintains VMC at all times. However, if the flightcrew should

lose OTW contact with the TTF, the approach may continue using the CDTI (and

ADS-B Guidance Display (AGD), if one is installed) to maintain visual separation

using the CAVS information alone.

B.5.3 Maneuver Termination. CAVS is intended to assist the flightcrew in maintaining visual

separation. The loss of CAVS information does not itself require discontinuing visual

separation, provided OTW visual contact with the TTF and safe separation can be

maintained. Discontinue using CAVS as a substitute for OTW visual contact under any of

the following conditions:

1. The flightcrew is unable to maintain VMC.

2. AGD (if installed) fails and OTW visual contact cannot be maintained.

3. AGD (if installed) information conflicts with the CDTI information to the extent that

it becomes a distraction, is confusing to the pilots, or it raises a concern about the

safety of the procedure.

4. Sustained loss of ADS-B data quality and/or integrity as indicated to the pilot via the

displays.

5. The caution level minimum range alert is activated.

6. If the flightcrew is unable to maintain a safe interval for any reason, they must

immediately advise ATC and request further clearance.

B.6 CAVS System. The CAVS authorization requires an aircraft to have an installed

ADS-B In system that meets the standards of TSO-C195b or later, or a system approved

by the Administrator intended for use in CAVS. For guidance on the installation of

CAVS equipment, refer to Advisory Circular (AC) 20-165, Airworthiness Approval of

Automatic Dependent Surveillance-Broadcast OUT Systems, and AC 20-172,

Airworthiness Approval for ADS-B In Systems and Applications.

B.7 Authorization to Conduct CAVS. FAA authorization is required for all U.S. aircraft

operators to conduct CAVS operations using ADS-B In (14 CFR part 119,

§ 119.49(a)(5)). This appendix provides guidance to operators on the process for

requesting issuance of this authorization, including guidance on the documentation that

should be submitted.

Note 1: For FAA authorization, refer to FAA Order 8900.1, Volume 3,

Chapter 18, Section 3, Operations Specification (OpSpec)/Management

Specification (MSpec)/Letter of Authorization (LOA) A355, Automatic

Dependent Surveillance-Broadcast (ADS-B) IN Operations.

Note 2: Operators may already hold other ADS-B In authorizations. There is no

need to submit documentation for a CAVS authorization if that documentation

has already been submitted for previous ADS-B In authorizations. The CAVS

application may include references to those duplicate documents instead.

12/30/19 AC 90-114B

Appendix B

B-4

B.7.1 Initial Request for Authorization. U.S. aircraft operators seeking to conduct CAVS

should first contact their assigned FAA office to indicate their intent. At the time of the

operator’s initial request, the FAA will provide the operator with a CAVS Application

Checklist, which should be completed with attached supporting documents.

B.7.2 Documentation to Submit With Formal Request.

B.7.2.1 Documentation Guidance. This section describes the documentation required

for submission of a formal CAVS proposal. The operator’s assigned principal

inspector (PI) may ask for additional information based on any unique aspects

of their specific operation. The operator should submit a letter of request for

issuance of authorization to the assigned PI. The letter of request should

include the following information:

• Type of aircraft (make, model, and series (M/M/S)).

• List of aircraft registration numbers (N-number) associated with the

request for authorization.

• ADS-B equipment complies with TSO-C195b or later, or as approved for

CAVS by the Administrator.

• Installation complies with guidance contained in AC 20-165 and

AC 20-172.

• Name of the ADS-B In (CAVS) software manufacturer and applicable

software version(s).

B.7.2.2 Airplane Flight Manual (AFM) Compliance Documentation. Operators

will submit documentation that demonstrates applicable aircraft have an

ADS-B In system that meets the performance standards of TSO-C195b or

later, or as otherwise approved by the Administrator, for CAVS operations.

B.7.2.3 Operation Manuals and Checklists. The certificate holder/operator/program

manager (as applicable) should submit information (e.g., Airplane Operations

Manual (AOM) bulletin or equivalent) to the flightcrews describing ADS-B to

include:

• CAVS system description;

• Normal procedures; and

• Non-normal or contingency procedures.

B.7.2.4 Maintenance. See Appendix C, ADS-B In Operations—Aircraft

Qualification and Maintenance, for applicable maintenance guidance.

B.7.2.5 Revision of Minimum Equipment List (MEL). See Appendix C for

guidance on the necessary MEL documents to be submitted for authorization

of CAVS.

12/30/19 AC 90-114B

Appendix B

B-5

B.7.2.6 Pilot Training. Submit applicable portions of proposed CAVS-specific pilot

training material and include a description of the methods used to conduct,

evaluate, and manage the training. The CAVS pilot training should include:

1. ADS-B Out/In system overview (if not previously addressed with another

ADS-B application).

2. ADS-B CAVS system operations.

3. CAVS normal procedures:

• Visual separation procedures.

• Speed management.

• Assessing closure rates.

• Wake turbulence avoidance.

• Weather minimums.

• Use of and response to the selectable CAVS range alert.

• Crew coordination during CAVS.

4. CAVS MEL procedures (as applicable).

5. CAVS equipment limitations.

6. CDTI interface.

7. Contingency procedures.

12/30/19 AC 90-114B

Appendix C

C-1

APPENDIX C. ADS-B IN OPERATIONS—AIRCRAFT QUALIFICATION AND

MAINTENANCE

C.1 Purpose. This appendix provides guidance on aircraft qualification, maintenance, and

maintenance personnel training associated with authorization of ADS-B In operations.

C.2 Applicability. The ADS-B In aircraft qualification and maintenance guidance contained

herein applies to operations conducted under 14 CFR parts 91, 91 subpart K (part 91K),

121, 125 (including part 125 Letter of Deviation Authority (LODA)), 129, and 135.

Part 91 operators (excluding part 91K operators) should comply with the guidance

contained in this appendix. Operators conducting operations under parts 91K, 121, 125

(including part 125 LODA), 129, and 135 should address all aspects of the guidance

contained in this appendix when submitting requests for authorization of ADS-B In

operations.

C.3 Aircraft Qualification.

C.3.1 ADS-B In systems must meet the standards of the appropriate Technical Standard Order

(TSO)-C195, Avionics Supporting Automatic Dependent Surveillance-Broadcast

(ADS-B) Aircraft Surveillance Applications (ASA), for authorization. Guidance on the

installation of ADS-B Out equipment can be found in Advisory Circular (AC) 20-165,

Airworthiness Approval of Automatic Dependent Surveillance-Broadcast OUT Systems.

Guidance on the installation of ADS-B In systems can be found in AC 20-172,

Airworthiness Approval for ADS-B In Systems and Applications.

C.3.2 Applications submitted to the FAA for authorization to conduct ADS-B In operations

should contain the following documentation to demonstrate aircraft qualification:

1. Applicable ADS-B In airworthiness documentation in the form of an aircraft type

certificate (TC), amended TC, or Supplemental Type Certificate (STC).

2. ADS-B In avionics manufacturer’s instructions for continued airworthiness (ICA),

as accepted by the FAA.

3. Proposed minimum equipment list (MEL) revisions, if applicable, listing all

limitations and procedures associated with the dispatch of aircraft with the ADS-B In

system inoperative.

C.4 Maintenance.

C.4.1 Maintenance of ADS-B In systems should comply with the guidance contained in this

section and must comply with applicable airworthiness regulations. Maintenance

personnel should be familiar with the operator’s ADS-B In system maintenance

procedures, their individual responsibilities with respect to those procedures, and the

availability of any resources within or outside of the maintenance organization necessary

to ensure the continued airworthiness of the ADS-B In system.

12/30/19 AC 90-114B

Appendix C

C-2

C.4.2 Applications submitted for authorization to conduct ADS-B In operations under parts 91,

91K, 121, 125 (including part 125 LODA), 129, and 135 should include documentation

that demonstrates compliance with the following, as applicable:

1. The General Maintenance Manual (GMM) should incorporate the ADS-B In

manufacturer’s ICA, as accepted by the FAA, and identify any special techniques,

maintenance/inspection frequencies, and test equipment used to support the continued

airworthiness of the system.

2. Indicate whether ADS-B In system maintenance is integrated into an existing

approved maintenance program or is a separate program.

3. Identify the GMM revision and update procedures, if not previously approved.

4. Identify how maintenance personnel will be trained on the ADS-B In system and the

method to record and maintain any associated qualifications.

5. Procedures for ADS-B In software installation, updates, evaluations, tests, and

configuration control.

6. Procedures used to make modifications, additions, and changes to the ADS-B In

system.

7. Procedures for ADS-B In discrepancy reporting and recording.

8. MEL and logbook procedures for deferral of the ADS-B In system or components of

the system.

9. Notification procedures between maintenance control, engineering, flight operations,

and dispatch (or equivalent) when the ADS-B In system is deferred.

10. Procedures to monitor and identify ADS-B In-equipped aircraft with chronic

discrepancies and restrict the aircraft from ADS-B In operations until appropriate

corrective action and verification tests have been performed.

11. Procedures for return to service of the ADS-B In system following routine/nonroutine

maintenance or completion of corrective action on an aircraft flagged for chronic

discrepancies.

12. Integration of ADS-B In maintenance into existing quality control (QC) and quality

assurance (QA) programs, as applicable.

C.5 Maintenance Personnel Training.

C.5.1 General. This paragraph contains guidance on maintenance personnel training associated

with ADS-B In operations. Operators should address this guidance, as applicable, in

proposals submitted to the FAA for authorization to conduct ADS-B In operations.

C.5.2 Maintenance Training. Maintenance personnel should be knowledgeable of the guidance

contained in this AC and applicable regulations. Operator and contract maintenance

personnel, including mechanics, maintenance controllers, avionics technicians, and

inspection/QA personnel should receive initial and recurrent training (as necessary) to

establish and maintain an effective ADS-B In maintenance program.

12/30/19 AC 90-114B

Appendix C

C-3

C.5.3 Application Submissions. Applications submitted for authorization to conduct ADS-B In

operations should address the following:

1. Identify the person(s) responsible for ensuring ADS-B In maintenance and inspection

personnel are properly trained, knowledgeable, and current in accordance with the

GMM.

2. Identify how the ADS-B In training will be conducted (i.e., in-house or outside

training provider).

3. Include policy and procedures that address any qualifications for ADS-B In

maintenance and inspection personnel.

4. Identify the methods and techniques used to conduct initial and recurrent training

(e.g., instructor-led training (ILT), computer-based training (CBT), and on-the-job

training (OJT)).

5. Identify the procedures used to record and maintain initial and recurrent ADS-B In

training and qualifications.

6. Include maintenance and inspection training curriculum that addresses the following

ADS-B In topics:

• Operational overview;

• Aircraft system overview;

• Maintenance and inspection procedures;

• Personnel training qualifications (as applicable);

• MEL procedures;

• Test equipment and use (as applicable); and

• Return to service test procedures.

12/30/19 AC 90-114B

Appendix D

D-1

APPENDIX D. DEFINITIONS

The terms have the following meaning when used in this advisory circular (AC):

D.1 Automatic Dependent Surveillance-Broadcast (ADS-B). ADS-B is a function on an

aircraft or vehicle that periodically broadcasts its state vector (i.e., horizontal and vertical

position, horizontal and vertical velocity) and other information.

D.2 Automatic Dependent Surveillance-Broadcast (ADS-B) Airspace. The airspace

specified in 14 CFR part 91, § 91.225.

D.3 Automatic Dependent Surveillance-Broadcast (ADS-B) Guidance Display (AGD).

The AGD provides digital readouts and alerts of time-sensitive information located on the

Cockpit Display of Traffic Information (CDTI). This is used primarily for installations

where the CDTI is not installed in the forward field of view (FOV).

D.4 Automatic Dependent Surveillance-Broadcast (ADS-B) In. ADS-B In is the receipt,

processing, and display of ADS-B transmissions. ADS-B In is necessary to utilize

ADS-B traffic and broadcast services (e.g., Flight Information Service-Broadcast (FIS-B)

and Traffic Information Service-Broadcast (TIS-B)).

D.5 Automatic Dependent Surveillance-Broadcast (ADS-B) Out. Transmission of an

aircraft’s position, altitude, velocity, and other information to other aircraft and air traffic

control (ATC) ground-based surveillance systems.

D.6 Automatic Dependent Surveillance-Rebroadcast (ADS-R). ADS-R is a

link-translation and rebroadcast function of the ADS-B ground system that allows both

ADS-B frequencies (1090 Extended Squitter (ES) and 978 megahertz (MHz)) to share

information.

D.7 Cockpit Display of Traffic Information (CDTI). This is a generic display that provides

the flightcrew with surveillance information about other aircraft, including position.

Traffic information may be obtained from one or multiple sources, including ADS-B,

Traffic Alert and Collision Avoidance System (TCAS), and TIS-B. The display of

information may be hosted on an Electronic Flight Bag (EFB) or the aircraft’s integrated

avionics suite.

D.8 Cockpit Display of Traffic Information (CDTI) Assisted Visual Separation (CAVS).

CAVS is an ADS-B In application that assists the flightcrew in maintaining visual

separation from ADS-B Out-equipped aircraft.

D.9 Extended Squitter (ES). ES is how ADS-B messages are transmitted from a Mode

Select (Mode S) transponder. ES is a long message (e.g., format DF=17) that Mode S

transponders transmit automatically, without interrogation by radar, to announce the

own-ship aircraft’s presence to nearby ADS-B-equipped aircraft and ground stations.

12/30/19 AC 90-114B

Appendix D

D-2

D.10 Flight Information Service-Broadcast (FIS-B). FIS-B is a ground broadcast service

provided over the 978 MHz frequency Universal Access Transceiver (UAT) data link.

The FAA FIS-B system provides pilots and flightcrews of properly equipped aircraft

(ADS-B In) with a flight deck display of certain aviation weather and aeronautical

information for advisory-only use.

D.11 Flightcrew. One or more flight deck crewmembers required for the operation of the

aircraft.

D.12 Global Navigation Satellite System (GNSS). The generic term for a satellite navigation

system, such as the Global Positioning System (GPS), that provides autonomous

worldwide geospatial positioning and may include local or regional augmentations.

D.13 Global Positioning System (GPS). GPS is a U.S. satellite-based radio navigation system

that provides a global positioning service. The service provided by GPS for civil use is

defined in the GPS Standard Positioning System (SPS) Performance Standard.

D.14 International Civil Aviation Organization (ICAO). A United Nations organization that

is responsible for developing international standards and for recommending practices and

procedures covering a variety of technical fields of aviation.

D.15 International Civil Aviation Organization (ICAO) 24-Bit Address (Mode S Code).

Address (octal format) assigned to each aircraft transponder or ADS-B transmitter during

registration or change of registration. The correct address is required, pursuant to

§ 91.227(d)(11), to be transmitted by both the installed transponder(s) and the ADS-B

Out system (1090ES/UAT). For aircraft equipped with Mode S transponders, their replies

to TCAS to enable proper operation of TCAS avionics and ATC ground systems

interrogations and their ADS-B transmissions should use the same 24-bit address,

allowing correlations by Airborne Surveillance and Separation Assurance Processing

(ASSAP).

D.16 In-Trail Procedures (ITP). ITP are designed primarily for use in nonradar oceanic

airspace to enable appropriately equipped ADS-B In aircraft to perform flight level (FL)

changes previously unavailable with procedural separation minima applied.

D.17 Mode A. One of a possible 4,096 identification codes that are transmitted from an aircraft

transponder or ADS-B transmitter to ground-based radars or ADS-B ground stations.

Secondary radars interrogate the aircraft transponder for the Mode A code. In ADS-B, the

aircraft includes its Mode A code as part of a transmitted ADS-B message. The Mode A

code is also known as the squawk code for the aircraft. The Mode A (military Mode 3) is

used in ATC for associating flight plans (FP) with surveillance data.

D.18 Mode C. The encoded barometric altitude from an onboard pressure sensor is contained

in the Mode C. This altitude information is transmitted by the aircraft transponder in

response to an appropriate interrogation from a secondary radar system. The Mode C is

used by ATC to determine the altitude of the reporting aircraft.

12/30/19 AC 90-114B

Appendix D

D-3

D.19 Mode S. A Secondary Surveillance Radar (SSR) system that operates using addressed

interrogation on 1030 MHz, and the transponder replies on 1090 MHz. Mode S systems

interrogate for aircraft identity (Mode A), altitude (Mode C), and other aircraft-specific

information. The aircraft transponder replies with the requested information. Mode S

supports a two-way frequency and an ADS-B service known as ES.

D.20 Non-Performing Equipment (NPE). ADS-B Out-equipped aircraft operating contrary

to § 91.225 and/or § 91.227.

D.21 Position Source. The onboard avionics equipment that provides the latitude, longitude,

geometric altitude, velocity, position and velocity accuracy metrics, and position integrity

metric to the ADS-B transmitter. Additionally, the position source may provide the

vertical rate parameters. Currently, only GPS, GPS with wide area augmentation systems

(WAAS), and Aircraft-Based Augmentation System (ABAS) sensors tightly integrated

with GPS are approved as position sources.

D.22 Secondary Surveillance Radar (SSR). A radar sensor that listens to replies sent by

transponders carried on onboard airborne targets. SSR sensors, in contrast to Primary

Surveillance Radar (PSR) sensors, require the aircraft under surveillance to carry a

transponder.

D.23 Statement of Compliance. The statement of compliance is a manufacturer-generated

document that states the ADS-B equipment, when installed in accordance with the

installation instructions, complies with all requirements of § 91.227, and with the

performance requirements of the appropriate Technical Standard Order (TSO).

D.24 Surveillance. Detection, tracking, characterization, and observation of aircraft, other

vehicles, weather, and airspace status information and phenomena for the purposes of

conducting flight operations in a safe and efficient manner. The primary purposes of

traffic surveillance (as distinct from all surveillance functionality) are to control the flow

of aircraft, to provide situational awareness for pilots and controllers, and to separate

aircraft.

D.25 Traffic Information Service-Broadcast (TIS-B). TIS-B is a ground broadcast service

provided from an ADS-B ground system network over the UAT and 1090ES links that

provides position, velocity, and other information on traffic that is detected by airport

surface detection equipment (ASDE), SSR, or Wide Area Multilateration (WAM), but

that is not transmitting an ADS-B position. TIS-B service will always be deployed with

the ADS-R service so that a complete traffic picture is provided for both non-equipped

and alternate-link-equipped aircraft.

D.26 Transponder. The airborne radar beacon receiver/transmitter portion of the ATC radar

beacon system (ATCRBS) or Mode S that automatically receives radio signals from

interrogators on the ground and selectively replies with a specific reply pulse or pulse

group only to those interrogations being received on the mode to which it is set to

respond.

12/30/19 AC 90-114B

Appendix D

D-4

D.27 Universal Access Transceiver (UAT). UAT is a wideband multipurpose data link

intended to operate globally on a single channel with a channel signaling rate of just over

1 megabit per second (Mbps). By design, UAT supports multiple broadcast services,

including FIS-B and TIS-B, in addition to ADS-B.

D.28 Visual Meteorological Conditions (VMC). Weather conditions in which pilots have

sufficient visibility to fly the aircraft while maintaining visual separation from terrain and

other aircraft. The exact requirements vary by class of airspace (e.g., Class B airspace:

3 statute miles (sm) visibility, clear of clouds).

12/30/19 AC 90-114B

Appendix E

E-1

APPENDIX E. RELATED REGULATIONS AND READING MATERIAL

E.1 Related Title 14 of the Code of Federal Regulations (14 CFR) Parts. You can find the

Code of Federal Regulations (CFR) online at http://www.ecfr.gov.

1. Part 1, § 1.1, General Definitions.

2. Part 21, § 21.50, Instructions for Continued Airworthiness and Manufacturer’s

Maintenance Manuals Having Airworthiness Limitations Sections.

3. Part 61, Certification: Pilots, Flight Instructors, and Ground Instructors.

4. Part 91, General Operating and Flight Rules:

• Section 91.1, Applicability;

• Section 91.103, Preflight Action;

• Section 91.130, Operations in Class C Airspace;

• Section 91.131, Operations in Class B Airspace;

• Section 91.135, Operations in Class A Airspace;

• Section 91.217, Data Correspondence Between Automatically Reported Pressure

Altitude Data and the Pilot’s Altitude Reference;

• Section 91.225, Automatic Dependent Surveillance-Broadcast (ADS-B) Out

Equipment and Use (refer to Registry Identification Number (RIN) 2120-AI92,

Automatic Dependent Surveillance-Broadcast (ADS-B) Equipage Mandate to

Support Air Traffic Control Service);

• Section 91.227, Automatic Dependent Surveillance-Broadcast (ADS-B) Out

Equipment Performance Requirements (refer to RIN 2120-AI92); and

• Subpart K (Part 91K), Fractional Ownership Operations.

5. Part 121, Operating Requirements: Domestic, Flag, and Supplemental Operations.

6. Part 125, Certification and Operations: Airplanes Having a Seating Capacity of 20 or

More Passengers or a Maximum Payload Capacity of 6,000 Pounds or More; and

Rules Governing Persons On Board Such Aircraft.

7. Part 133, Rotorcraft External-Load Operations.

8. Part 135, Operating Requirements: Commuter and On Demand Operations and Rules

Governing Persons On Board Such Aircraft.

9. Part 137, Agricultural Aircraft Operations.

12/30/19 AC 90-114B

Appendix E

E-2

E.2 Related Reading Materials (current editions).

• You can find this and other advisory circulars (AC) on the FAA’s website at

http://www.faa.gov/regulations_policies/advisory_circulars.

• Inspectors can access FAA Order 8900.1 via the Flight Standards Information

Management System (FSIMS) at http://fsims.avs.faa.gov. Air carriers, operators, and

the public can access Order 8900.1 at http://fsims.faa.gov.

• You can find a current list of Technical Standard Orders (TSO) on the FAA’s

Regulatory and Guidance Library (RGL) website at http://rgl.faa.gov.

E.2.1 FAA Guidance Material.

1. AC 20-165, Airworthiness Approval of Automatic Dependent Surveillance-Broadcast

OUT Systems.

2. AC 20-172, Airworthiness Approval for ADS-B In Systems and Applications.

3. Order 8900.1, Volume 3, Chapter 18, Section 3, OpSpec/MSpec/LOA A354,

Automatic Dependent Surveillance-Broadcast (ADS-B) In-Trail Procedure (ITP).

4. Aeronautical Information Manual (AIM), paragraphs 4-5-7 through 4-5-10.

5. Surveillance and Broadcast Services Description Document, SRT-047 (current

revision).

E.2.2 FAA TSOs (edition listed below or later).

1. TSO-C112d, Air Traffic Control Radar Beacon System/Mode Select

(ATCRBS/Mode S) Airborne Equipment.

2. TSO-C129a, Airborne Supplemental Navigation Equipment Using the Global

Positioning System (GPS).

3. TSO-C145c, Airborne Navigation Sensors Using the Global Positioning System

Augmented by the Satellite Based Augmentation System.

4. TSO-C146c, Stand-Alone Airborne Navigation Equipment Using the Global

Positioning System Augmented by the Satellite Based Augmentation System.

5. TSO-C154c, Universal Access Transceiver (UAT) Automatic Dependent

Surveillance-Broadcast (ADS-B) Equipment Operating on Frequency of 978 MHz.

6. TSO-C157a, Aircraft Flight Information Services-Broadcast (FIS-B) Data Link

Systems and Equipment.

7. 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).

12/30/19 AC 90-114B

Appendix E

E-3

8. TSO-C195, Avionics Supporting Automatic Dependent Surveillance-Broadcast

(ADS-B) Aircraft Surveillance Applications (ASA).

9. TSO-C196a, Airborne Supplemental Navigation Sensors for Global Positioning

System Equipment using Aircraft-Based Augmentation.

E.2.3 RTCA, Inc. Documents.

1. 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).

2. RTCA DO-282, Minimum Operational Performance Standards for Universal Access

Transceiver (UAT) Automatic Dependent Surveillance - Broadcast (ADS-B).

3. RTCA DO-312 Supplement, Safety, Performance and Interoperability Requirements

Document for the In Trail Procedure in Oceanic Airspace (ATSA-ITP) Application.

4. RTCA DO-317B, Minimum Operational Performance Standards (MOPS) for Aircraft

Surveillance Applications (ASA) System.

5. RTCA DO-354, Safety and Performance Requirements Document for CDTI Assited

Visual Separation (CAVS).

E.3 European Union Aviation Safety Agency (EASA) Publications (current editions):

1. 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.

2. EASA Certification Specifications and Acceptable Means of Compliance Airborne

Communications, Navigation and Surveillance (CS-ACNS).