U.S. Department
of Transportation
Federal Aviation
Administration
Advisory
Circular
Subject: Automatic Dependent
Surveillance-Broadcast (ADS-B)
Operations
Date: 9/21/12
Initiated by: AFS-400
AC No: 90-114
Change: 1
1. PURPOSE. The intent of this advisory circular (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, which are required
after January 1, 2020.
2. PRINICIPAL CHANGES. This change creates a new Appendix 2, Automatic Dependent
Surveillance-Broadcast (ADS-B) In-Trail Procedure (ITP). Preexisting Appendices 2 and 3 are
now renumbered to 3 and 4.
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Appendix 2 12/8/11 Appendix 3 9/21/12
Appendix 3 12/8/11 Appendix 4 9/21/12
ORIGINAL SIGNED by
/s/
John M. Allen
Director, Flight Standards Service
U.S. Department
of Transportation
Federal Aviation
Administration
Advisory
Circular
Subject: Automatic Dependent
Surveillance-Broadcast (ADS-B)
Operations
Date: 9/21/12
Initiated by: AFS-400
AC No: 90-114
Change: 1
The Federal Aviation Administration (FAA) has issued a new rule contained in 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. This advisory circular (AC) provides users of the NAS guidance on a means of
conducting flight operations in accordance with §§ 91.225 and 91.227. The Aeronautical
Information Manual (AIM) provides an overview of, and the appendices in this AC provide
guidance for, additional operations enabled by ADS-B. Appendix 3 contains a list of
ADS-B-related definitions.
Comments and suggestions for improving this publication should be directed to:
AFS ADS-B Branch (AFS-406)
470 L’Enfant Plaza East
Suite 4102
Washington, DC 20024
9/21/12 AC 90-114 CHG 1
CONTENTS
Paragraph Page
CHAPTER 1. ADS-B OPERATIONS
1-1. Purpose..............................................................................................................................1
1-2. Audience...........................................................................................................................1
1-3. Scope.................................................................................................................................1
1-4. Cancellation ......................................................................................................................1
CHAPTER 2. OVERVIEW AND SYSTEM DESCRIPTION
2-1. Overview...........................................................................................................................3
2-2. ADS-B System Description..............................................................................................3
2-3. ADS-B Broadcast Services...............................................................................................4
CHAPTER 3. OPERATIONAL CONSIDERATIONS
3-1. U.S. ADS-B Airspace and Equipment Performance Requirements .................................5
Figure 1, Automatic Dependent Surveillance-Broadcast Airspace Rule (§ 91.225)
Diagram ............................................................................................................................6
3-2. Exceptions to Airspace Requirements..............................................................................6
CHAPTER 4. OPERATING PROCEDURES
4-1. General Operating Procedures..........................................................................................7
4-2. Operator Familiarity of the Installed ADS-B System.......................................................7
4-3. ADS-B Equipment Operations (U.S.-Designated Airspace)............................................7
4-4. Flight Plans .......................................................................................................................8
4-5. Preflight Requirements (U.S.-Designated Airspace) (Reserved) .....................................8
4-6. Flightcrew Entry of Required ADS-B Data......................................................................8
APPENDIX 1. ADS-B OUT OPERATIONS OUTSIDE OF U.S.-DESIGNATED
AIRSPACE (8 pages)..........................................................................................1
Table 1. Canadian-Specific Surveillance Phraseology.......................................................6
Table 2. Australian-Specific Surveillance Phraseology......................................................7
APPENDIX 2. AUTOMATIC DEPENDENT SURVEILLANCE-BROADCAST (ADS-B)
IN-TRAIL PROCEDURE (ITP) (14 pages).....................................................1
Figure 1. Reduction of Aircraft Separation Minima with In-Trail Procedure......................1
Figure 2. In-Trail Procedure Distances Illustrated...............................................................3
Figure 3. Similar Track ........................................................................................................4
Figure 4. In-Trail Procedure Climb/Descent Variations......................................................7
Table 1. In-Trail Procedure Initiation/Maneuver Criteria (Reference RTCA DO 312) ...12
Table 2. Flightcrew Free Text Controller-Pilot Data Link Communication Message Set
for In-Trail Procedure.........................................................................................13
Table 3. Controller Free Text Controller-Pilot Data Link Communication Message Set
for In-Trail Procedure.........................................................................................14
APPENDIX 3. DEFINITIONS (4 pages)....................................................................................1
APPENDIX 4. RELATED REGULATIONS AND READING MATERIAL (4 pages)........1
Page iii
12/8/11 AC 90-114
Par 1-1 Page 1 (and 2)
CHAPTER 1. ADS-B OPERATIONS
1-1. PURPOSE. The intent of this advisory circular (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, which are required
after January 1, 2020.
1-2. AUDIENCE. This AC applies to all U.S. operators intending to use ADS-B.
1-3. SCOPE. This AC contains an overview of the ADS-B system and general operating
procedures associated with operations conducted in compliance with the airspace and
performance requirements of §§ 91.225 and 91.227. The appendices provide guidance for
additional operations enabled by ADS-B.
a. Obligation. The information contained in this AC is not mandatory; it describes an
acceptable means but not the only means of complying with the applicable regulations. This AC
does not change, create, amend, or permit deviation from any regulatory requirement.
b. Authorization to Conduct ADS-B OUT Operations. There is no authorization
required by the Federal Aviation Administration (FAA) to conduct ADS-B OUT operations in
the airspace specified in § 91.225 (U.S.-designated airspace).
c. Certification and Installation of ADS-B OUT Equipment.
(1) 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 (ADS-B) OUT Equipment for Operation in the National
Airspace System (NAS).
NOTE: Outside the U.S. National Airspace System (NAS), many worldwide
air traffic service providers (ATSP) allow the use of ADS-B equipment
certified to the European Aviation Safety Agency (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, dated February 5, 2008.
NOTE: ADS-B equipment installed in accordance with AC 20-165
(TSO-C166b and TSO-C154c) meets the equipment requirements of
AMC 20-24. However, AMC 20-24 equipment does not comply with § 91.225.
(2) Until further notice, ADS-B OUT equipment must be installed in accordance with
the Flight Standards Service (AFS)/Aircraft Certification Service (AIR) memorandum, Approval
for ADS-B OUT Systems. A copy of this memorandum can be obtained from the FAA
Regulatory and Guidance Library (RGL) Web site at http://rgl.faa.gov.
1-4. CANCELLATION. This AC and AC 20-165 cancel AC 120-86, Aircraft Surveillance
Systems and Applications, dated September 16, 2005.
12/8/11 AC 90-114
CHAPTER 2. OVERVIEW AND SYSTEM DESCRIPTION
2-1. OVERVIEW. To accommodate the ever-growing demands placed on the NAS, limitations
associated with the current system must be overcome. Beginning with the NAS-wide
implementation of ADS-B, the FAA has begun a transformation to both overcome existing
limitations and to enable the 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.
a. ADS-B System Architecture. The ADS-B system architecture is composed of aircraft
avionics and a ground infrastructure. Onboard 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 ground stations for use by ATC; to ADS-B-equipped
aircraft; and to other aviation service providers.
b. 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 1, Automatic Dependent
Surveillance-Broadcast (ADS-B) Airspace Rule (§ 91.225) Diagram, for airspace and frequency
requirements.
(1) 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) 978 MHz Frequency. ADS-B equipm
ent operating on 978 MHz are referred to as
Universal Access Transceivers (UAT) in this AC.
c. ADS-B Avionics Operating Modes. ADS-B avionics can have the ability to both
transmit and receive information.
(1) ADS-B OUT. The transmission of ADS-B information from aircraft is known as
ADS-B OUT.
(2) ADS-B IN. The receipt of ADS-B infor
mation by an aircraft is known as
ADS-B IN.
NOTE: After January 1, 2020, all aircraft operating within the airspace
defined in § 91.225 will be required to transmit (ADS-B OUT) the
information defined in § 91.227 using Technical Standard Order (TSO)-
C166b or TSO-C154c avionics.
Par 2-1 Page 3
AC 90-114 12/8/11
Page 4 Par 2-3
2-3. ADS-B BROADCAST SERVICES. ADS-B implementation includes three broadcast
services: Automatic Dependent Surveillance-Rebroadcast (ADS-R), TIS-B, and FIS-B.
a. 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 operating on the alternate frequency to process and use
the other’s information. This process is referred to as ADS-R and occurs within the ADS-B
ground station.
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.
b. TIS-B. TIS-B is the broadcast of transponder-based 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.
c. FIS-B. The 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 SA. Additional information on FIS-B and the products available through the service are
provided in the Aeronautical Information Manual (AIM).
12/8/11 AC 90-114
CHAPTER 3. OPERATIONAL CONSIDERATIONS
3-1. U.S. ADS-B AIRSPACE AND EQUIPMENT PERFORMANCE REQUIREMENTS.
After January 1, 2020, unless authorized by ATC, all aircraft operating in the airspace specified
in § 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.
a. Inside Class A Airspace. Operation
s in Class A airspace must:
(1) Meet the equipment requirements in TSO-C166b (1090ES); and
(2) Meet the equipment performance requirem
ents 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.
b. Outside Class A Airspace. Operations outside Class A airspace must:
(1) Meet the equipment performance requirements of § 91.227;
(2) Meet the requirements in TSO-C166b (1090ES); or
(3) Meet the requirements in TSO-C154c in the following airspace:
(a) Class B and Class C airspace;
(b) Except as provided for in § 91.225(e), within 30 nautical miles (NM) of an
airport listed in part 91 appendix D (Mode C veil), section 1, from the surface upward
to 10,000 feet mean sea level (MSL);
(c) Above the ceiling and within the lateral boundaries of a Class B or Class C
airspace designated for an airport upward to 10,000 feet MSL;
(d) Except as provided for in § 91.225(e), Class E airspace within the 48 contiguous
United States and the District of Colum
bia at and above 10,000 feet MSL, excluding the airspace
at and below 2,500 feet above the surface (i.e., mountainous areas); and
(e) Class E airspace at and above 3,000 feet MSL over the Gulf of Mexico, from
the
coastline of the United States out to 12 NM.
Par 3-1 Page 5
AC 90-114 12/8/11
Page 6 Par 3-1
FIGURE 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. These
aircraft may conduct operations without ADS-B OUT in the airspace specified in § 91.225(d)(2)
and (4). While the requirements do not apply to these aircraft, the aircraft operator requires the
approval of ATC before entering ADS-B-required airspace. Operations specified in
§ 91.225(d)(2) must be conducted:
Outside any Class B or Class C airspace, and
Below the altitude of the ceiling of a Class B or Class C airspace designated for an
airport, or 10,000 feet MSL, whichever is lower.
12/8/11 AC 90-114
CHAPTER 4. OPERATING PROCEDURES
4-1. GENERAL OPERATING PROCEDURES. This chapter describes the general
procedures for ADS-B OUT operations in accordance with § 91.225. 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.
a. System Operation Familiarity. All operators should use the applicable Airplane Flight
Manual (AFM), 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.
b. 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 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.
c. 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, resulting 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.-DESIGNATED AIRSPACE).
a. Transmit Requirements. In acco
rdance 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. This equipment operation requirement pertains to all phases of flight operation, including
airport surface movement area operations. For ADS-B installations integrated within a
transponder, the flight manual, checklists, and any operator’s procedures manuals must be
updated accordingly with proper ADS-B system operations guidance.
NOTE: Aircraft must comply with the appropriate TSO requirements when
transmitting ADS-B data.
b. ATC-Authorized Deviations. Requests for ATC-authorized deviations from the
requirem
ents in § 91.225(g) must be made to the ATC facility that has jurisdiction over the
concerned airspace or airport movement area and be made within the time periods specified
below:
Par 4-1 Page 7
AC 90-114 12/8/11
Page 8 Par 4-3
(1) For operation of an aircraft with inoperative ADS-B equipment to the airport of
ultimate destination (including any intermediate stops) 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, the request must be
m
ade at least 1 hour before the proposed operation.
4-4. FLIGHT PLANS. Whe
n operating aircraft equipped with ADS-B OUT, operators should
indicate their ADS-B capability on the flight plan as “RMK/ADSB.”
4-5. PREFLIGHT REQUIREMENTS (U.S.-DESIGNATED AIRSPACE). Reserved.
4-6. FLIGHTCREW ENTRY OF REQUIRED ADS-B DATA. Operational procedures shall
be developed by the operator to address flightcrew entry of the ADS-B m
essage elements
required in § 91.227 and as described in subparagraphs 4-6a through d. 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 to
enter the information multiple times through the appropriate system’s interface and to ensure that
conflicting aircraft identification information is not transmitted to ATC.
a. Mode A Code.
(1) ATC automation relies on the Mode A code to identify aircraft under radar
surveillan
ce and to correlate the displayed target to a flight plan. The Mode A code is one
element of the transmitted ADS-B message set. Because 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 a flight
plan route.
(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.
b. Aircraft’s Call Sign/Flight ID.
(1) The AFM or POH should provide specific instructions for entering the registration
number or flight plan call sign, sometimes referred to as the flight ID. The term “aircraft call
sign” means the radiotelephony call sign assigned to an aircraft for voice communications
purposes. For General Aviation (GA) aircraft, the aircraft call sign is normally associated with
the aircraft registration number (tail number) and may be preset. For airline and commuter
aircraft, it is usually composed of the company name and flight number (and therefore not linked
12/8/11 AC 90-114
to a particular airframe). The airline flight ID entered into the flight management system
(FMS)/multipurpose control and display unit (MCDU) must exactly match the aircraft ID in the
ATC flight plan.
(2) For operations using variable call signs (e.g., Lifeguard), the operator should verify
with equipm
ent manufacturers that this capability is available in the avionics and should obtain
guidance for the proper procedures to enter variable call sign codes.
c. Emergency Status.
(1) This ADS-B message element and transponder code alerts AT
C that the aircraft is
experiencing emergency conditions and indicates the type of emergency. The appropriate
emergency code should be entered into the transponder (i.e., 7500, 7600, and 7700). The
International Civil Aviation Organization (ICAO) Annex 10, Volume IV emergency codes
(general emergency, no communications, and unlawful interference) are required by § 91.227.
(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.
(3) ADS-B systems not integrated with the transponder or systems with optional
emergency codes require the appropriate emergency code to be entered through a separate pilot
interface. Flightcrews must ensure that both emergency codes (ADS-B and transponder) are
identical.
d. Aircraft’s “IDENT.” The required 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.
Par 4-6 Page 9 (and 10)
12/8/11 AC 90-114
Appendix 1
APPENDIX 1. ADS-B OUT OPERATIONS OUTSIDE OF U.S.-DESIGNATED
AIRSPACE
1. Overview. ADS-B provides air traffic control (ATC) with a means of surveillance outside of
U.S.-designated airspace, which allows application of reduced separation standards for more
efficient use of the airspace. Currently, ADS-B provides surveillance coverage in several regions
of the world, including portions of Australia, Canada, and in the Asia-Pacific region. Additional
International Civil Aviation Organization (ICAO) regions and Member States are expected to
implement ADS-B in their airspace and/or on specific airways and routes in the future.
2. Authorization to Conduct ADS-B OUT Operations Outside of U.S.-Designated
Airspace. FAA authorization is required for all U.S. operators to conduct ADS-B OUT
operations outside of U.S.-designated airspace. This appendix provides guidance to operators on
the process and documentation required when requesting issuance of this authorization.
NOTE: As applicable, authorization under FAA Order 8900.1, Flight
Standards Information Management System (FSIMS), Volume 3,
Chapter 18, Section 3, Part A Operations Specifications—General,
operations specification (OpSpec) A353 and a regional authorization
(e.g., OpSpec B050) may be necessary to conduct ADS-B operations in areas
outside of U.S.-designated airspace.
a. Initial Request for Authorization.
(1) U.S. operators seeking to conduct ADS-B OUT operations outside of U.S.-designated
airspace must first contact their assigned FAA office to indicate their intent. When making the
initial request, the operator should be prepared to provide the following:
(a) Documented compliance of applicable requirements;
(b) The proposed plan to conduct operations under the authorization; and
(c) The identification of the appropriate point(s) of contact (POC) for coordination
during the FAA authorization process.
(2) At the time of the operator’s initial request, the F
AA will provide the operator with
information for obtaining relevant guidance and documents, as well as the proper content and
format of the documentation required when submitting the formal request.
b. Required Documentation for Submission of Formal Request.
(1) Documentation Guidance. The following paragraph provides general guidance on
the docum
entation required for submission of a formal request for issuance of this authorization.
At the discretion of the operator’s assigned principal inspector (PI), additional information may
be required based on any unique aspects of specific operations.
Page 1
AC 90-114 12/8/11
Appendix 1
Page 2
(2) Letter of Request for Issuance of Authorization. The operator must submit a letter
of request to the assigned PI requesting issuance of the authorization. The letter of request should
include statements indicating the following:
(a) Proposed region(s) of operation;
(b) Type of aircraft (make, model, and series (M/M/S)) to be used in the operations;
(c) Description of ADS-B OUT equipment to be used;
(d) Revision of aircraft qualification documents (Airplane Flight Manual (AFM),
pilot’s operating handbook (POH), etc.);
(e) Establishment of applicable operational procedures and practices;
(f) Revision of applicable operations manuals and checklists;
(g) Revision of ADS-B OUT system maintenance procedures;
(h) Establishment of periodic maintenance for the ADS-B OUT system;
(i) Revision of minimum equipment list (MEL), if applicable;
(j) Revision of pilot training; and
(k) Revision of dispatcher training, if applicable.
c. Compliance Documentation. Operators must submit documentation that demonstrates
compliance with European Aviation Safety Agency (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, dated
February 5, 2008. Documentation should include:
(1) Aircraft Qualification Documentation. Documentation fro
m the aircraft
manufacturer stating in the AFM/AFMS, POH that the proposed aircraft complies with EASA
AMC 20-24. Deviations, as stated in EASA AMC 20-24, must be included or referenced.
NOTE: ADS-B equipment installed in accordance with the current edition of
AC 20-165, Airworthiness Approval of Automatic Dependent
Surveillance-Broadcast OUT Equipment for Operation in the National
Airspace System (NAS), meets the equipment requirements of EASA
AMC 20-24. See AMC 20-24 for any additional maintenance, operational,
and training considerations.
(2) Operational Procedures and Practices. As applicable, com
pany manuals must
address the special characteristics of the proposed region of operation.
(3) Operations Manuals and Checklists. The AFM, Airplane F
light Manual
Supplement (AFMS), Aircraft Operating Manual (AOM), Flight Operations Manual (FOM),
12/8/11 AC 90-114
Appendix 1
POH, and associated checklists, as applicable to the specific operator, must include information
to be used for the specific operation requested and be carried on the aircraft. The operations
manual (or equivalent) should include a system description, operational and contingency
procedures, and training elements for use of the ADS-B NRA application. Operations manuals
should indicate that Direct Controller Pilot Communications (DCPC) must be available at all
times (e.g., very high frequency (VHF), Controller-Pilot Data Link Communication
(CPDLC), etc.). Operations manuals and checklists should indicate that when there is not an
independent flight deck control selection between the ADS-B OUT on/off function and the ATC
transponder on/off function, the crew must be fully aware that disabling the ADS-B function will
also disable transponder and Traffic Alert and Collision Avoidance System (TCAS) functions.
(4) Maintenance Procedures. The operator must submit documentation indicating the
proposed maintenance procedures that address the instructions for continued airworthiness (ICA)
provided by the manufacturer of the installed ADS-B equipment. Maintenance procedures must
include a periodic verification check of aircraft-derived data used by the ADS-B system.
Maintenance procedures must also include periodic verification (using suitable ramp test
equipment or other acceptable means) that the correct ICAO 24-bit address assigned to each
aircraft is being transmitted by the ADS-B system.
(5) Establishment of Periodic Checks of the ADS-B OUT System. The operator
should provide documentation that indicates that periodic checks for the installed ADS-B OUT
system are established.
(6) Revision of MEL. The operator must submit documentation for proposed MEL
(if used) revisions that address appropriate dispatch procedures of the aircraft with the
ADS-B OUT system inoperative or partially inoperative.
(7) Pilot Training. Pilots conducting operations under this authorization must be trained
in the use and limitations of the installed ADS-B system, unless one of the crewmembers is an
ADS-B-trained check airman, as appropriate. Operators must submit documentation that details
the method and content of the pilot training to be conducted. Pilot training must address the
following:
ADS-B operating procedures;
Flight planning;
MEL procedures;
Human factors;
ADS-B phraseology applicable to specific regions of operation (see Table 1,
Canadian-Specific Surveillance Phraseology, and Table 2, Australian-Specific
Surveillance Phraseology);
ADS-B system operation, including normal/abnormal procedures;
Correct entry of ICAO aircraft ID as applicable to the flight;
Operational procedures regarding the transmission of the generic emergency code
(i.e., 7700) in cases when the flightcrew actually selected a discrete emergency
code (e.g., 7500, 7600);
Page 3
AC 90-114 12/8/11
Appendix 1
Handling of data source errors (e.g., discrepancies between navigation data
sources); and
Incident reporting procedures.
(8) Dispatcher/Flight Follower Training. Operators m
ust submit a detailed description
of the proposed dispatcher/flight follower (if required/used) training to be conducted.
Dispatcher/flight follower training must address the following:
Dispatch of aircraft with the ADS-B system unserviceable or partially
unserviceable.
Flight planning, fuel loading, and route change procedures associated with
ADS-B operations.
ADS-B ICAO region-specific requirements.
3. Canada-Specific Requirements.
a. Transport Canada Requirements. See the cu
rrent edition of Transport Canada
AC 700-009, Automatic Dependent Surveillance-Broadcast, Paragraph 6.2, Foreign Air
Operators, for information related to the ADS-B requirements of foreign operators.
b. NAV CANADA Requirements. See the current edition of Aeronautical Information
Circular (AIC) 21/09, Air Traffic Flow Management in the Vicinity of Hudson Bay as a Result
of Automatic Dependent Surveillance-Broadcast OUT Implementation, for information related to
NAV CANADA ATC services supported by ADS-B.
4. Australia-Specific Requirements. See the current editions of Australia AIC H09/11,
Transition to Satellite Technology for Navigation and Surveillance; Australia Civil Aviation
Safety Authority (CASA) Civil Aviation Order (CAO) 20.18, Aircraft Equipment—Basic
Operational Requirements, regarding avionics requirements; and CAO 82.5, Condition on Air
Operators’ Certificates Authorising Regular Public Transport Operations in High Capacity
Aircraft, for information related to the ADS-B requirements of certificated foreign operators.
5. Asia-Pacific-Specific Requirement. Singapore issued AIC 14/10, Introduction to Automatic
Dependent Surveillance Broadcast (ADS-B) OUT Service within Parts of the Singapore FIR,
dated December 28, 2010, informing aircraft operators regarding the Civil Aviation Authority of
Singapore’s (CAAS) plan to implement ADS-B operations after 2013 within portions of the
Singapore flight information region (FIR). See CAAS AIC 14/10 for specific airways that will
require ADS-B within Singapore’s FIR.
6. Related Documents.
a. ICAO Regional Guidance. Regulatory guidance and general inform
ation for
ADS-B OUT operations for specific ICAO regions can be found in the following publications:
(1) FAA Order 8900.1, Flight Standards Information Management Systems (FSIMS),
Volume 3, Chapter 18, Section 3, Part A Operations Specifications—General, Operations
Specifications/Management Specifications/Letter of Authorization A353, Automatic Dependent
Page 4
12/8/11 AC 90-114
Appendix 1
Page 5
Surveillance-Broadcast (ADS-B) Operations Outside of U.S.-Designated Airspace, current
edition;
(2) EASA AMC 20-24, Certification Considerations for the Enhanced ATS in Non-Radar
Areas using ADS-B Surveillance (ADS-B-NRA) Application via 1090 MHZ Extended Squitter,
dated February 5, 2008;
(3) TCCA AC 700-009, Automatic Dependent Surveillance-Broadcast, current edition;
(4) NAV CANADA AIC 21/09, Air Traffic Flow Management in the Vicinity of Hudson
Bay as a Result of Automatic Dependent Surveillance-Broadcast OUT Implementation, current
edition;
(5) CASA CAO 20.18, Aircraft Equipment—Basic Operational Requirements, current
edition;
(6) CASA CAO 82.5, Condition on Air Operators’ Certificates Authorising Regular
Public Transport Operations in High Capacity Aircraft, current edition; and
(7) CAAS AIC 14/10, Introduction to Automatic Dependent Surveillance Broadcast
(ADS-B) OUT Service within Parts of the Singapore FIR, current edition.
b. Additional Information. For additional information regarding specific NRA operations,
contact the following organizations or individuals:
(1) Contact the Flight Technologies and Procedures Division (AFS-400) by phone at
202-385-4586 or by email at 9-AWA-AVS-ADS-Programs-AFS/AWA/FAA.
(2) For additional information on 14 CFR parts 121 and 135 special authorizations
(300-series OpSpecs), contact the Air Transportation Division (AFS-200) at 202-267-8166.
(3) For additional information on 14 CFR parts 91 and 125 special authorizations
(300-series OpSpecs/m
anagement specifications (MSpec)/letters of authorization (LOA)),
contact the General Aviation and Commercial Division (AFS-800) at 202-267-8212.
AC 90-114 12/8/11
Appendix 1
TABLE 1. CANADIAN-SPECIFIC SURVEILLANCE PHRASEOLOGY
Existing “Radar” Phraseology
New Generic “Surveillance” Phraseology
RADAR SERVICE TERMINATED
(non-radar routing if required)
SURVEILLANCE SERVICE TERMINATED
(non-surveillance routing if required)
RADAR SERVICE TERMINATED DUE TO
(reason)
SURVEILLANCE SERVICE TERMINATED
DUE TO (reason)
SECONDARY RADAR OUT OF SERVICE
ADS-B SURVEILLANCE OUT OF SERVICE
DUE TO (reason)
MODE CHARLIE NOT VALIDATED
PRESSURE ALTITUDE NOT VALIDATED
MODE CHARLIE IS INVALID
PRESSURE ALTITUDE IS INVALID
RADAR SERVICE TERMINATED
SURVEILLANCE SERVICE TERMINATED
RESUME POSITION REPORTS
RESUME POSITION REPORTS
(aircraft IDENT) RADAR IDENTIFIED
(position if required)
(aircraft IDENT) IDENTIFIED
(position if required)
(aircraft IDENT) RADAR IDENTIFICATION
LOST
(aircraft IDENT) IDENTIFICATION LOST
POINT OUT (position)
(identification/Secondary Surveillance Radar
(SSR) code) (track and altitude)
(other information)
POINT OUT (position) (identification/SSR code)
(track and altitude) (other information)
CONFIRM ADS-B ELIGIBLE? and if
necessary—UNABLE TO ISSUE
CLEARANCE INTO ADS-B
EXCLUSIONARY AIRSPACE, MAINTAIN
(altitude)
NEGATIVE ADS-B DUE TO EQUIPMENT
FAILURE
IF ABLE, CHANGE YOUR FLIGHT ID TO
(FLIGHT ID)
IF YOU READ, (appropriate instructions),
then—(Action) OBSERVED, WILL
CONTINUE RADAR CONTROL
IF YOU READ, (appropriate instructions),
then—(Action) OBSERVED, WILL
CONTINUE SURVEILLANCE CONTROL
(ACID) READING YOU ON 7700
CONFIRM THE NATURE OF YOUR
EMERGENCY
Page 6
12/8/11 AC 90-114
Appendix 1
Page 7 (and 8)
TABLE 2. AUSTRALIAN-SPECIFIC SURVEILLANCE PHRASEOLOGY
Existing “Radar” Phraseology New Generic “Surveillance” Phraseology
IDENTIFICATION TERMINATED
(reason)
IDENTIFICATION TERMINATED
(reason)
PRIMARY RADAR OUT OF SERVICE
ADS-B OUT OF SERVICE (reason)
SECONDARY RADAR OUT OF SERVICE
ADS-B OUT OF SERVICE (reason)
ADVISE TRANSPONDER CAPABILITY ADVISE ADS-B CAPABILITY
NEGATIVE TRANSPONDER NEGATIVE ADS-B
RE-ENTER MODE S AIRCRAFT
IDENTIFICATION
RE-ENTER ADS-B AIRCRAFT
IDENTIFICATION
SQUAWK IDENT TRANSMIT ADS-B IDENT
STOP SQUAWK STOP ADS-B TRANSMISSION
SQUAWK CHARLIE TRANSMIT ADS-B ALTITUDE
STOP SQUAWK CHARLIE WRONG
INDICATION
STOP ADS-B ALTITUDE TRANSMISSION
(reason)
9/21/12 AC 90-114 CHG 1
Appendix 2
APPENDIX 2. AUTOMATIC DEPENDENT SURVEILLANCE-BROADCAST (ADS-B)
IN-TRAIL PROCEDURE (ITP)
1. PURPOSE. This appendix provides a description of the Automatic Dependent
Surveillance-Broadcast (ADS-B)-enabled In-Trail Procedure (ITP) and guidance to operators
seeking Federal Aviation Administration (FAA) authorization to conduct ITP operations.
2. BACKGROUND. The ITP is designed primarily for use in non-radar 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 allow ITP maneuvers to occur safely with reduced
separation minima applied. ITP will enable flightcrews to execute FL changes to improve ride
comfort, avoid weather, or obtain more favorable winds to improve fuel economy and arrival
times.
a. ITP Scenario. Figure 1, Reduction of Aircraft Separation Minima with In-Trail
Procedure, illustrates a basic ITP scenario. The ITP aircraft (blue) wishes to climb from FL 340
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.
b. ATC Responsibility. ATC maintains separation responsibility throughout the ITP
maneuver, and resumes the appropriate separation minima at its completion. The reduced ITP
separation may only be applied between a qualified ITP aircraft and no more than two reference
aircraft for the duration of the maneuver. Reference aircraft do not require ADS-B IN equipment
and are only required to be transmitting an ADS-B OUT signal of sufficient quality.
FIGURE 1. REDUCTION OF AIRCRAFT SEPARATION MINIMA WITH IN-TRAIL
PROCEDURE
FL360
FL340
FL350
ALLOWED
ITP CriteriaITP Criteria
ITP Aircraft
Reference Aircraft (ADS-B Out required)
ADS-B not required
Desired Altitude
Procedural Separation
FL360
FL340
FL350
ALLOWED
ITP CriteriaITP Criteria
ITP Aircraft
Reference Aircraft (ADS-B Out required)
ADS-B not required
Desired Altitude
FL360
FL340
FL350
ALLOWED
ITP CriteriaITP Criteria
FL360
FL340
FL350
ALLOWED
ITP CriteriaITP Criteria
ITP Aircraft
Reference Aircraft (ADS-B Out required)
ADS-B not required
ITP Aircraft
Reference Aircraft (ADS-B Out required)
ADS-B not required
Desired Altitude
Procedural SeparationProcedural Separation
3. ITP TERMINOLOGY.
a. Closing Groundspeed Differential. The difference between the ITP aircraft’s
groundspeed and a reference aircraft’s groundspeed that results in a reduction of the ITP
distance.
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AC 90-114 CHG 1 9/21/12
Appendix 2
Page 2
b. 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.
c. ITP Aircraft. An aircraft operated by a flightcrew authorized to conduct an ITP.
d. ITP Criteria. A set of conditions that m
ust be satisfied prior to initiating or executing an
ITP clearance.
e. ITP Distance. The dis
tance 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 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 Procedures for Air Navigation Services - Air Traffic Management
(PANS-ATM) DOC 4444, section 5.4.2.6.4.
f. ITP Equipment. The onboard avionics required to support an ITP.
g. Reference Aircraft. Aircraft (no more than two) transmitting valid ADS-B data which
meet specified criteria and are referenced as part of an ITP clearance request to ATC.
9/21/12 AC 90-114 CHG 1
Appendix 2
FIGURE 2. IN-TRAIL PROCEDURE DISTANCES ILLUSTRATED
4. ITP CONCEPT. The ITP concept is based on the aircraft satisfying specific initial
conditions, and the flightcrew prom
ptly 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, the closing Mach differential, as well as accuracy and integrity of the
ADS-B data transmitted from participating aircraft. (See Table 1, In-Trail Procedure
Initiation/Maneuver Criteria (reference RTCA DO-312).) The procedure further requires that the
ITP aircraft maintain constant Mach, and climb or descend at a minimum of 300 feet per minute
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AC 90-114 CHG 1 9/21/12
Appendix 2
Page 4
(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. ITP Distance and Groundspeed Differential Criteria. The initia
l 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 closing ground speed
differential, the distance between the aircraft should not become less than the ITP minimum
separation of 10 NM.
c. Relative Altitude Criteria. The reference aircraft may not be more than 2,000 feet above
or below the ITP aircraft.
d. Similar Track Criteria. The ITP aircraft and an
y reference aircraft must be on similar
tracks. Similar tracks are defined here as less than 45 degrees from one another. (See
Figure 3, Similar Track).
e. Mach Differential. In order to ensure an acceptable closure throughout the ITP
maneuver, the controller may 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:
Using the cruise Mach numbers of the ITP and reference aircraft where the Mach
number technique is being used;
Requesting Mach numbers from the ITP and reference aircraft; or
Any other methodology determined appropriate and acceptable by the regulatory
authority and the Air Navigation Service Provider (ANSP).
f. ADS-B Data Quality Criteria. Only ADS-B OUT aircraft, broadcasting data of
sufficient quality may be used as reference aircraft for ITP. Own ship data quality must also be
sufficient to ensure safe separation. The data quality criteria are:
Position accuracy for ITP and reference aircraft—ITP and reference aircraft data with
horizontal position accuracies of at least 0.5 NM (95 percent).
Position integrity for ITP and reference aircraft—ITP and reference aircraft data with
horizontal position integrity bounds of 1.0 NM @ 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 knots) 95
percent.
9/21/12 AC 90-114 CHG 1
Appendix 2
FIGURE 3. SIMILAR TRACK
5. ITP DESCRIPTION. To properly conduct an ITP, a qualified flightcrew m
ust use
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 will 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. 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 will indicate to the flightcrew whether all initiation criteria are satisfied.
b. Flightcrew Requests ITP. If the criteria are satisfied, the flightcrew requests the ITP
clearance using the appropriate phraseology. Direct Controller Pilot Communications (DCPC) is
required; however, 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, and flightcrews must use free text messages as described in Table 2,
Flightcrew Free Text Controller-Pilot Data Link Communication Message Set for In-Trail
Procedure, and Table 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 to allow the controller to properly evaluate the request.
NOTE: ATC must not issue an ITP clearance to any aircraft unless that
aircraft has initiated the request.
c. Controller Issues Clearance. Upon receipt of an ITP request, the controller:
(1) Confirms the ITP aircraft and the reference aircraft are on th
e 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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AC 90-114 CHG 1 9/21/12
Appendix 2
Page 6
(b) Same Track includes the concept of Similar Track (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.
(3) Ensures both the ITP aircraft and reference aircraft are not maneuvering and not
expected to maneuver during the ITP.
(a) 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.
d. 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 must immediately reject the ATC clearance and terminate
the maneuver. Additionally, if the FL, reference aircraft, or type of maneuver (ITP versus
standard FL change) does not match their request, or if the flightcrew receives an ITP clearance
without requesting one, they must not perform the maneuver and should verify with ATC to
confirm the clearance.
e. 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 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 must be completed.
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 vertical
speed. Upon completion of the maneuver, notify ATC of the ITP data loss.
g. Approved ITP Variations. An ITP can be conducted with a m
aximum of two reference
aircraft. The reference aircraft may not be more than 2,000 feet of altitude above or below the
ITP aircraft, but there is no limit on the amount 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
9/21/12 AC 90-114 CHG 1
Appendix 2
one behind. Figure 4, In-Trail Procedure Climb/Descent Variations, depicts the approved ITP
variations.
h. 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/she shall:
(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 International Civil Aviation Organization (ICAO) document PANS-ATM,
DOC 4444, Section 15.2, Special Procedures for In-Flight Contingencies in Oceanic Airspace.
FIGURE 4. IN-TRAIL PROCEDURE CLIMB/DESCENT VARIATIONS
6. AUTHORIZATION TO CONDUCT ITP. Authorization from
the FAA is required to
conduct ITP. To receive authorization, operators should submit ITP proposals to their
appropriate certificate management office (CMO), certificate-holding district office (CHDO), or
Flight Standards District Office (FSDO) using the guidance contained in this section. ITP
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AC 90-114 CHG 1 9/21/12
Appendix 2
proposals must be evaluated and approved by the applicable FAA Flight Standards Service
(AFS) policy divisions in Washington, DC, prior to authorization.
NOTE: Operators holding an active authorization for other ADS-B IN
applications with specific requirements duplicated by those for ITP may
reference such authorization requirements in their proposal as a means to
demonstrate compliance with applicable ITP requirements.
a. Request for Authorization.
(1) Request for Authorization. U.S. operators seeking to conduct ITP must first
contact their assigned FAA office to indicate their intent. When making an initial request, the
operator should be prepared to provide the following:
(a) General information (aircraft, equipment, region of operation, etc.) about the
proposed plan to conduct operations under the authorization; and
(b) The identification of the appropriate point(s) of contact (POC) for coordination
during the FAA authorization process.
(2) At the time of the operator’s initial request, the FAA will provide the operator with
information for obtaining relevant guidance and documents, as well as the proper content and
format of the documentation required when submitting the formal request.
b. Required Documentation for Submission of Formal Proposal.
(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 operation.
(2) Proposal Requirements. A separate proposal should be submitted for each aircraft
type when making initial and subsequent requests for authorization to conduct ITP. Subsequent
requests to add additional aircraft of the same make, model, and series (M/M/S) to an existing
authorization should include the aircraft and equipment documentation required in paragraphs 4,
5, and 6 of this appendix.
(3) Letter of Request for Issuance of Authorization. The operator must submit a
letter of request to the assigned PI requesting issuance of the authorization. The letter of request
should include statements indicating the following:
(a) Proposed region(s) of operation;
(b) Type of aircraft M/M/S to be used;
(c) Description of ADS-B OUT/IN equipment to be used;
Page 8
9/21/12 AC 90-114 CHG 1
Appendix 2
(d) Revision of aircraft documents (Airplane Flight Manual (AFM), pilot’s
operating handbook (POH), etc.);
(e) Establishment of applicable operational procedures and practices;
(f) Revision of applicable operations manuals and checklists;
(g) Revision of ADS-B IN system maintenance procedures;
(h) Revision of minimum equipment list (MEL), if applicable;
(i) Revision of pilot training; and
(j) Revision of dispatcher training (if applicable) or other persons with operational
control.
(4) Aircraft Qualification. To conduct ITP, aircraft must have an ADS-B IN system
that meets the standards of the current edition of Technical Standard Order (TSO)-C195a,
Avionics Supporting Automatic Dependent Surveillance-Broadcast (ADS-B) Aircraft
Surveillance Applications (ASA). For guidance on the installation of ITP equipment, refer to the
current edition of Advisory Circular (AC) 20-165, Airworthiness Approval of Automatic
Dependent Surveillance-Broadcast (ADS-B) OUT Systems, and AC 20-172, Airworthiness
Approval for ADS-B IN Systems and Applications.
(5) Aircraft Equipment. Submit a description of the ITP equipment configuration to
indicate the type of display (e.g., integrated with an existing display or hosted on a standalone
display), location of the controls, and specifically include:
(a) ITP aircraft M/M/S;
(b) ITP aircraft registration numbers; and
(c) ITP equipment configuration data including:
Surveillance processo
r Part Number (P/N).
Transponder/ADS-B system P/N.
ITP display P/N.
(6) Airworthiness. Submit instructions for continued airworthiness and return to
service (RTS) maintenance procedures applicable to the ADS-B IN and ITP system equipment
and software.
(7) Flight Manual/POH Documentation. Include relevant sections of the AFM,
Aircraft Flight Manual Supplem
ent (AFMS), or POH, which describe the ITP specific:
(a) System description;
(b) Cockpit setup procedures;
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AC 90-114 CHG 1 9/21/12
Appendix 2
Page 10
(c) En route procedures;
(d) Communications; and
(e) Non-normal, contingency, and emergency procedures.
(8) Proposed ITP Operations Area. Authorization
s to conduct ITP will be limited to
specific regions of the world where the ANSP offers ITP and those procedures are determined to
be acceptable to the Administrator. Include in your request a description, by flight information
region (FIR) and ANSP, of the operational areas where you propose to conduct ITP. If you hold
a B050 authorization, submit a draft B050 paragraph which includes the operational areas where
you propose to conduct ITP, including applicable notes.
(9) Dispatch/Flight Planning. Subm
it 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 as a description of the methods used to conduct,
evaluate, and manage training.
(a) Recommended ITP Training Content. The following contains the recommended
information to be included in dispatch/flight planning training material:
General understanding of ADS-B IN operations;
Route requirements;
Equipment requirements; and
Procedures for entry of applicable ADS-B equipment codes on flight plan.
(10) 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.
(a) Recommended ITP Training Content. The following contains the recommended
information to be included in pilot training material:
General understanding of ADS-B IN operations (technology, capabilities,
and limitations).
ITP system operation, including:
Normal procedures.
Abnormal, contingency, and emergency procedures.
ITP flight planning considerations.
ITP dispatch considerations (as applicable).
MEL considerations (as applicable).
ITP terminology, including proper formulation of an CPDLC ITP
request/clearance.
ITP equipment limitations.
9/21/12 AC 90-114 CHG 1
Appendix 2
Explanation of ITP distance as distinct from aircraft range, using select
scenario-based examples (refer to Figure 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.
ITP aircraft on a parallel track of reference aircraft.
(11) 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. (Refer to
paragraph 3, ITP Terminology, for the exact description, and Figure 2 for examples.) Since the
ITP software will be 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
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 2.
(a) Lateral Traffic Filters. Some ITP avionics may 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. Training should include recommended technique for its use.
(b) ITP Initiation Criteria. Traffic displayed as an ADS-B IN target may not be
made available 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. Refer to Table 1 for ITP initiation criteria.
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AC 90-114 CHG 1 9/21/12
Appendix 2
Page 12
TABLE 1. IN-TRAIL PROCEDURE INITIATION/MANEUVER CRITERIA
(REFERENCE RTCA DO 312)
In-Trail Procedure (ITP)
Speed/Distance Criteria
ITP Distance >= 15 nautical miles (NM) and
Closing Ground Speed Differential <= 20 knots
ITP Distance >= 20 NM and Closing Ground
Speed Differential <= 30 knots
Relative Altitude Criteria Difference in altitude between the 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 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 @ 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 knots) 95%
Closing Mach Differential (Air
Traffic Control (ATC)
Crosscheck)
Closing Mach Differential equal or less than
0.06 Mach
9/21/12 AC 90-114 CHG 1
Appendix 2
TABLE 2. FLIGHTCREW 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 flight
identification]”
1 reference aircraft (behind) “ITP [Distance] AHEAD OF [Aircraft flight
identification]”
2 reference aircraft (both ahead) “ITP [Distance] BEHIND[Aircraft flight
identification] AND [Distance] BEHIND
[Aircraft flight identification]”
2 reference aircraft (both behind) “ITP [Distance] AHEAD OF [Aircraft flight
identification] AND [Distance] AHEAD OF
[Aircraft flight identification]”
2 reference aircraft (one ahead and one
behind)
“ITP [Distance] BEHIND [Aircraft flight
identification] AND [Distance] AHEAD OF
[Aircraft flight identification]”
To request an ITP climb or descent, the flightcrew will send a 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 2.
Example of ITP request message: REQUEST CLIMB TO FL360 ITP 25NM BEHIND
SIA228 AND 21NM AHEAD OF AFR008.
NOTE: This preformatted free text message set will be used until an
appropriate message set is implemented.
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AC 90-114 CHG 1 9/21/12
Appendix 2
Page 14
TABLE 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 flight identification]”
1 reference aircraft (behind) “ITP AHEAD OF [Aircraft flight identification]”
2 reference aircraft (both ahead) “ITP BEHIND [Aircraft flight identification] AND
BEHIND [Aircraft flight identification]”
2 reference aircraft (both behind) “ITP AHEAD OF [Aircraft flight identification] AND
AHEAD OF [Aircraft flight identification]”
2 reference aircraft (one ahead and one
behind)
“ITP BEHIND [Aircraft flight identification] AND
AHEAD OF [Aircraft flight identification]”
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 3:
Example of ITP clearance message: ITP BEHIND SIA228 AND AHEAD OF AFR008
CLIMB TO FL360 REPORT LEVEL FL360.
NOTE: The controller should never issue an ITP clearance unless one has
been requested by a flightcrew.
NOTE: This preformatted free text message set will be used until an
appropriate message set is implemented.
9/21/12 AC 90-114 CHG 1
Appendix 3
APPENDIX 3. DEFINITIONS
The following terms have the meaning listed when used in this AC:
a. Automatic Dependent Surveillance-Broadcast (ADS-B). ADS-B is a function on an
aircraft or vehicle that periodically broadcasts its state vector (horizontal and vertical position,
horizontal and vertical velocity) and other information.
b. ADS-B Airspace. The airspace specified in 14 CFR part 91, § 91.225.
c. 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. 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.
e. 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.
f. 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.
g. Flightcrew. One or more cockpit crewmembers required for the operation of the
aircraft.
h. Flight Information Service-Broadcast (FIS-B). FIS-B is a ground broadcast service
provided over the Universal Access Transceiver (UAT) data link. The FAA FIS-B system
provides pilots and flightcrews of properly equipped aircraft with a cockpit display of certain
aviation weather and aeronautical information.
i. Global Navigation Satellite System (GNSS). The gener
ic 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.
j. 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 Performance Standard, 4th edition.
k. 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.
Page 1
AC 90-114 12/8/11
Appendix 3
l. ICAO 24-Bit Address. Address assigned to each aircraft transponder or ADS-B
transmitter. For aircraft equipped with Mode S transponders, their replies to Traffic Alert and
Collision Avoidance System (TCAS) interrogations and their ADS-B transmissions should use
the same 24-bit address, allowing correlations by Airborne Surveillance and Separation
Assurance Processing (ASSAP).
m. 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 with surveillance data.
n. 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.
o. 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.
p. Position Source. The onboard avionics equipment that provides the latitude, longitude,
geometric altitude, velocity, position and velocity accuracy metrics, and position integrity metric.
Additionally, the position source may provide the vertical rate parameters.
q. 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.
r. 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 (SA) for pilots and controllers, and to separate aircraft.
s. 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.
t. 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
Page 2
12/8/11 AC 90-114
Appendix 3
Page 3 (and 4)
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.
u. 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.
9/21/12 AC 90-114 CHG 1
Appendix 4
Page 1
APPENDIX 4. RELATED REGULATIONS AND READING MATERIAL
1. RELATED 14 CFRs. You can find the CFRs online at www.gpoaccess.gov/ecfr.
Part 1, § 1.1, General Definitions.
Part 21, § 21.50, Instructions for Continued Airworthiness and Manufacturer’s
Maintenance Manuals Having Airworthiness Limitations Sections.
Part 61, Certification: Pilots, Flight Instructors, and Ground Instructors.
Part 91:
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 (see RIN 2120-A192);
Section 91.227, Automatic Dependent Surveillance-Broadcast (ADS-B) Out
Equipment Performance Requirements (See RIN 2120-A192); and
Subpart K (Part 91K), Fractional Ownership Operations.
Part 121, Operating Requirements: Domestic, Flag, and Supplemental Operations.
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.
Part 133, Rotorcraft External-Load Operations.
Part 135, Operating Requirements: Commuter and On Demand Operations and Rules
Governing Persons On Board Such Aircraft.
Part 137, Agricultural Aircraft Operations.
2. RELATED READING MATERIAL.
You can find this and other ACs on the FAA W
eb site at
http://www.faa.gov/regulations_policies/advisory_circulars.
Inspectors can access FAA Order 8900.1, Flight Standards Information Management
System (FSIMS), through http://fsims.avs.faa.gov. Air carriers, operators, and the public
can access Order 8900.1 through http://fsims.faa.gov.
You can find a current list of Technical Standard Orders (TSO) on the FAA Regulatory
and Guidance Library (RGL) Web site at http://rgl.faa.gov.
AC 90-114 12/8/11
Appendix 4
a. FAA Guidance Material (current editions):
(1) AC 20-165, Airworthiness Approval of Automatic Dependent Surveillance-Broadcast
Out Equipment for Operation in the National Airspace System (NAS);
(2) AC 20-172, Airworthiness Approval for ADS-B I
N Systems and Applications;
(3) FAA Order 8900.1, Flight Standards Information Managem
ent Systems (FSIMS),
Volume 3, Chapter 18, Section 3, Part A Operations Specifications—General, Operations
Specifications/Management Specifications/Letter of Authorization A353, Automatic Dependent
Surveillance-Broadcast (ADS-B) Operations; and
(4) Aeronautical Information Manual (AIM).
b. FAA TSOs:
(1) TSO-C112(), Air Traffic Control Radar Beacon System/Mode Select
(ATCRBS/Mode S) Airborne Equipment;
(2) TSO-C129(), Airborne Supplemental Navigation Equipment Using the Global
Positioning System (GPS);
(3) TSO-C145(), Airborne Navigation Sensors Using the Global Positioning System
Augmented by the Satellite Based Augmentation System;
(4) TSO-C146(), 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-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);
(7) TSO-C195, Avionics Supporting Automatic Dependent Surveillance-Broadcast
(ADS-B) Aircraft Surv
eillance Applications (ASA); and
(8) TSO-C196(), Airborne Supplemental Navigation Sensors for Global Positioning
System Equipment Using Aircraft Based Augmentation.
3. INTERNATIONAL PUBLICATIONS (current editions).
a. Asia-Pacific. Civil Aviation Authority of Singapore (CAAS), Aeronautical Information
Circular (AIC) 14/10, Introduction to Automatic Dependent Surveillance Broadcast (ADS-B)
Out Service within Parts of the Singapore FIR.
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12/8/11 AC 90-114
Appendix 4
b. Australia.
(1) Australia AIC H09/11, Transition to Satellite Technology for Navigation and
Surveillance;
(2) Civil Aviation Safety Authority (CASA) Civil Aviation Order (CAO) 20.18, Aircraft
Equipm
ent—Basic Operational Requirements; and
(3) CASA CAO 82.5, Condition on Air Operators’ Certificates Authorising Regular
Public Transport Operations in High Capacity Aircraft.
c. Canada.
(1) Transport Canada AC 700-009, Automatic Dependent Surveillance-Broadcast; and
(2) NAV CANADA AIC 21/09, Air Traffic Flow Managem
ent in the Vicinity of Hudson
Bay as a Result of Automatic Dependent Surveillance Broadcast Out Implementation.
d. Europe.
(1) EASA AMC 20-24, Certification Considerations for the Enhanced ATS in Non Radar
Areas using ADS-B Surveillance (ADS-B-NRA) Application via 1090 MHz Extended Squitter,
dated February 5, 2008;
(2) The European Organization for the Safety of Air Navigation (EUROCONTROL),
Flight Crew Guidance for Flight Operations in ADS-B Only Surveillance Airspace, dated
February 7, 2008;
(3) EUROCONTROL, Guidance for the Provision of Air Traffic Services Using ADS-B
in Non Radar Airspace (NRA), dated January 28, 2008; and
(4) International Civil Aviation Organization (ICAO) Asia and Pacific Offices ADS-B
Implementation and Operations Guidance Document, current edition.
Page 3 (and 4)
