AC 90-114A

Historical

Advisory circular · Automatic Dependent Surveillance-Broadcast Operations

A newer version is currentThis is a historical version. AC 90-114C is the version in force, approved January 14, 2025.
Approved
October 28, 2014
Last reviewed
July 29, 2024
Cancelled by
AC90-114A CHG 1
Family
AC 90-114 · 7 versions
Revision
A
14 CFR parts
91
14 CFR sections
§ 91.225§ 91.227

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 21, 2025.

Show pages 1–8

CHAPTER 3. OPERATIONAL CONSIDERATIONS

3-1. U.S. AUTOMATIC DEPENDENT SURVEILLANCE-BROADCAST (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 Title 14 of the Code of Federal Regulations (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.

a. Inside Class A Airspace. Operations in Class A airspace must:

(1) Meet the equipment 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 Radio Frequency of 1090 Megahertz (MHz) (1090ES).

(2) Meet the equipment performance 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.

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, Universal Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on Frequency of 978 MHz, 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 Columbia at and above 10,000 feet MSL, excluding the airspace at and below 2,500 feet above the surface (i.e., mountainous areas).

Par 3-1 Page 7

(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.

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.

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.

Par 3-1 Page 8

CHAPTER 4. OPERATING PROCEDURES

4-1. GENERAL OPERATING PROCEDURES. This chapter describes the general procedures for Automatic Dependent Surveillance-Broadcast (ADS-B) Out operations in accordance with Title 14 of the Code of Federal Regulations (14 CFR) part 91, § 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), 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.

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 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.

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, 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.-DESIGNATED AIRSPACE).

a. 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.

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 Technical Standard Order (TSO) requirements when transmitting ADS-B data.

b. Air Traffic Control (ATC)-Authorized Deviations. Operators must make requests for ATC-authorized deviations from the requirements in § 91.225(g) to the ATC facility that has jurisdiction over the concerned airspace or airport movement area within the time periods specified below:

Par 4-1 Page 9

(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, operators must make the request at least 1 hour before the proposed operation.

4-4. FLIGHT PLANS (FP). When operating aircraft equipped with ADS-B, operators must indicate their surveillance equipment code in field 10B of the U.S. Area Navigation (RNAV) and International Civil Aviation Organization (ICAO) FPs.

a. Transponder Codes. The transponder codes for ADS-B are as follows:

(1) E: Mode S, including Aircraft Identification (ACID), pressure-altitude and Extended Squitter (ES) (ADS-B) capability.

(2) L: Mode S, including ACID, pressure-altitude, ES (ADS-B) and enhanced surveillance capability.

b. Surveillance Codes. The surveillance codes for ADS-B are as follows:

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

(2) B2: ADS-B with dedicated 1090 MHz ADS-B Out and In capability.

(3) U1: ADS-B Out capability using Universal Access Transceiver (UAT).

(4) U2: ADS-B Out and In capability using UAT.

c. ICAO FP Block 18 ADS-B Information.

(1) If ADS-B capability filed in item 10 is compliant with TSO-C166b, which is based on RTCA, Inc. DO-260B, annotate “SUR/260B.” If ADS-B capability filed in item 10 is compliant with TSO-C154c, which is compliant with RTCA DO-282B, include the item “SUR/282B.”

(2) When ADS-B capability is filed in item 10, include CODE/Aircraft address expressed in the form of six hexadecimal characters (e.g., “CODE/HJF34B”).

NOTE: For a complete description of FP filing codes, including field 18, refer to the Federal Aviation Administration (FAA) Flight Planning Information Web site at http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/e nroute/flight_plan_filing.

Par 4-3 Page 10

4-5. PREFLIGHT REQUIREMENTS (U.S.-DESIGNATED AIRSPACE). Reserved.

4-6. FLIGHTCREW ENTRY OF REQUIRED ADS-B DATA. The operator must develop operational procedures to address flightcrew entry of the ADS-B message 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 ACID information is not transmitted to ATC.

a. Mode A Code.

(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 National Airspace System (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.

(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 Identification (FLT ID).

(1) An aircraft’s FLT ID, also known as registration number or airline flight number, is transmitted by the ADS-B Out avionics. The FLT ID is comprised of a maximum of seven alphanumeric characters and also corresponds to the ACID annotated on the ATC FP. The FLT ID for airline and commuter aircraft is associated with the company name and flight number

(e.g., AAL3342). 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 (CP). The FLT ID for General Aviation (GA) aircraft is 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.

Par 4-4 Page 11

(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 pilots ensure the FLT ID entry correctly matches the ACID annotated in the filed ATC FP prior to departure.

(3) For operations using variable call signs (e.g., Lifeguard), the operator should verify with equipment 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 ATC that the aircraft is experiencing emergency conditions and indicates the type of emergency. The appropriate emergency code should be entered into the transponder (e.g., 7500, 7600, and 7700). The ICAO Annex 10, Volume IV, Surveillance Radar and Collision Avoidance, 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 may 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 12

Appendix 1 APPENDIX 1. ADS-B OUT OPERATIONS OUTSIDE OF U.S.-DESIGNATED

AIRSPACE

1. PURPOSE. This appendix provides a description of the Automatic Dependent Surveillance-Broadcast (ADS-B) operations outside of U.S.-designated airspace and guidance to operators seeking Federal Aviation Administration (FAA) authorization to conduct ADS-B operations outside of U.S.-designated airspace.

2. BACKGROUND. Countries around the world are implementing ADS-B technology to enhance or extend the surveillance capability of their air traffic control (ATC) systems.

A number of these countries have published new rules that will mandate ADS-B equipage on aircraft operating in certain classes of airspace. Other countries have chosen not to mandate ADS-B equipage, but have designated specific routes and airspace to benefit those who equip voluntarily. A certain subset of these countries further requires that foreign operators obtain operational approval from their State of Registry to access ADS-B airspace. FAA authorization is required for all U.S. aircraft operators, seeking access to foreign ADS-B airspace where State of Registry operational approval is required.

3. APPLICABILITY. The following information identifies FAA approval requirements for U.S. aircraft operators in the following foreign ADS-B airspace.

a. Australia. Operations Specification (OpSpec)/Management Specification (MSpec)/Letter of Authorization (LOA) A153, Automatic Dependent Surveillance-Broadcast (ADS-B) Operations Outside of U.S.-Designated Airspace, is not required. Approved ADS-B avionics will be required, for all operations at or above flight level (FL) 290. (Refer to the current edition of Australian Civil Aviation Safety Authority (CASA) Advisory Circular (AC) 21-45, Airworthiness Approval of Airborne Automatic Dependent Surveillance-Broadcast Equipment.

b. Canada. OpSpec/MSpec/LOA A153 is not required. Approved ADS-B avionics will be required when an operator seeks operational benefit from ADS-B Out equipage in the airspace defined in the current editions of NAV CANADA Aeronautical Information Circular (AIC) 31/11, Air Traffic Services Associated with Automatic Dependent Surveillance-Broadcast Out Surveillance, and AIC 29/13, Automatic Dependent Surveillance-Broadcast Service in the Gander Oceanic Control Area.

c. China (Sanya). Authorization, per OpSpec/MSpec/LOA A153, is required. A153 is required for all U.S. aircraft operators flying over performance-based navigation routes L642 or M771 at or above FL290 within the Sanya flight information region (FIR).

d. China (Taipei). Authorization, per OpSpec/MSpec/LOA A153, is required. A153 is required for all U.S.-registered aircraft flying over routes B576 or B591 at or above FL290 within the Taipei FIR. For additional information regarding ADS-B operations within the Taipei FIR, refer to Republic of China Civil Aeronautics Administration AIC 02/12, Introduction of ADS-B Out Service within Taipei FIR.

Appendix 1

e. Europe. OpSpec/MSpec/LOA A153 is not required. Regulation (European Union (EU)) No. 1207/2011 provides surveillance requirements within the European air traffic management network (EATMN) as well as the upcoming implementation dates. However, an amendment to the current regulation has been endorsed, which proposes a change in the existing implementation dates.

f. Fiji. OpSpec/MSpec/LOA A153 is not required. Fiji has mandated ADS-B equipage only for Fiji-registered aircraft operating in controlled airspace. For additional information regarding ADS-B operations, refer to the current editions of the Civil Aviation Authority of the Fiji Islands (CAAFI) Air Navigation Regulations 1981 and Fiji AIC 04/11, Operation of Foreign Registered Aircraft in Fiji.

g. Hong Kong. OpSpec/MSpec/LOA A153 is required. Authorization, per A153, is required for all U.S. aircraft operators flying over performance-based navigation routes L642 or M771 at or above FL290 within the Hong Kong FIR. Additionally, A153 will be required for all U.S. aircraft flying within the entire Hong Kong FIR at or above FL290. For further information regarding ADS-B operations within the Hong Kong FIR, refer to the current edition of Hong Kong AIC 09/11, Automatic Dependent Surveillance-Broadcast (ADS-B) Out Operations.

h. India. OpSpec/MSpec/LOA A153 will be required. ADS-B Out implementation in India is aimed at providing redundancy where radar surveillance is already available. The provision of Air Traffic Service (ATS) surveillance services using ADS-B Out information, in terminal and en route airspace, to eligible aircraft, on an opportunity basis, is envisaged to continue until India considers mandating the carriage of ADS-B Out equipment on a date TBD.

For additional information regarding ADS-B operations, refer to India Aeronautical Information Regulation and Control (AIRAC) Aeronautical Information Publication (AIP) Supplement 18/2014, Automatic Dependent Surveillance-Broadcast (ADS-B) Out Based ATS Surveillance Services.

i. Republic of Indonesia. OpSpec/MSpec/LOA A153 will be required. Implementation of ADS-B in Indonesia, for situational awareness (SA) by ATC, will be effective on September 18, 2014 at 1900 universal coordinated time (UTC) until June 25, 2015. Indonesian regulatory changes establish mandatory aircraft fitment of ADS-B avionics equipment for the operation of any aircraft in Indonesian airspace at or above FL290 after the compliance date of June 25, 2015. Until that date, carriage of ADS-B equipment remains voluntary. For additional information regarding ADS-B operations, refer to Republic of Indonesia AIRAC AIP Supplement 10/14, Automatic Dependent Surveillance-Broadcast (ADS-B) Implementation in Indonesia for Situational Awareness.

j. Republic of Seychelles. OpSpec/MSpec/LOA A153 is not required. Approved ADS-B Out equipment will be required in all controlled airspace. For additional information regarding ADS-B operations, refer to Republic of Seychelles AIC 02/2014, Mandatory Carriage of GNSS Navigation Equipment, ADS-B and Mode S Transponders in SEYCHELLES Airspace.

k. Singapore. OpSpec/MSpec/LOA A153 is required. Authorization, per A153, is required for all U.S. aircraft operators operating on ATS routes N891, M753, L642, M771, L644, and N892 at FL290 and above within the Singapore FIR. For additional information regarding Page 2

Appendix 1 ADS-B operations within the Singapore FIR, refer to Civil Aviation Authority of Singapore (CAAS) AIC 14/10, Introduction of Automatic Dependent Surveillance-Broadcast (ADS-B) Out Services within Parts of the Singapore FIR.

l. Vietnam. Authorization, per OpSpec/MSpec/LOA A153, is required. A153 is required for all U.S.-registered aircraft flying over ATS routes L625, M771, N892, L642, M765, M768, N500, and L628 at or above FL290 within the Ho Chi Minh FIR. For additional information regarding ADS-B operations within the Ho Chi Minh FIR, refer to Civil Aviation Authority (CAA) of Vietnam AIC 03/13, Implementation of ADS-B within Ho Chi Minh FIR.

m. Additional Regions. As additional regions are implementing ADS-B, U.S. aircraft operators are advised to monitor the regions applicable to their operation for any changes related to ADS-B requirements and to comply with Title 14 of the Code of Federal Regulations (14 CFR) part 91, § 91.703. Normally, these types of advisories are transmitted through State AIPs and/or AICs.

4. AUTHORIZATION TO CONDUCT ADS-B OPERATIONS OUTSIDE OF U.S.-DESIGNATED AIRSPACE WHERE STATE OF REGISTRY OPERATIONAL APPROVAL IS REQUIRED. FAA authorization is required for all U.S. aircraft operators seeking access to foreign ADS-B airspace where State of Registry operational approval is required. This appendix provides guidance to operators on the process and documentation required when requesting issuance of this authorization.

NOTE: For FAA authorization, refer to FAA Order 8900.1, Flight Standards Information Management System (FSIMS), Volume 3, Chapter 18, Section 3, OpSpec/MSpec/LOA A153.

a. Initial Request for Authorization. U.S. aircraft 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. At the time of the operator’s initial request, the FAA will provide the operator with an OpSpec/MSpec/LOA A153 Application Checklist (found in the A153 guidance section of the Web-based Operations Safety System (WebOPSS) or at http://www.faa.gov/nextgen/programs/adsb/ under Quick Links), which must be completed and included with attached support documents when submitting a formal request for authorization.

b. Required Documentation for Submission of Formal Request.

(1) Documentation Guidance. The following paragraph provides general guidance on the documentation 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. 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:

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

(b) Airplane registration number(s) and serial number(s).

Appendix 1

(c) Make, model, and part number of the ADS-B transmitter and positioning source installed on each airplane.

(d) Areas of intended operation.

NOTE: The guidance contained in subparagraph 4b of this appendix will also be annotated on the OpSpec/MSpec/LOA A153 Application Checklist provided to the operator by the applicable FAA field office.

(2) Airplane Flight Manual (AFM) Compliance Documentation. The operator will provide a copy of the AFM, Aircraft/Airplane Flight Manual Supplement (AFMS), Airplane Operations Manual (AOM), or pilot’s operating handbook (POH), as appropriate, which states that the aircraft’s ADS-B Out system complies with any of the following:

(a) Section 91.227.

(b) The current edition of AC 20-165, Airworthiness Approval of Automatic Dependent Surveillance Broadcast (ADS-B) Out Systems.

(c) 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 (until rescinded).

NOTE: The following is an example of an AFM statement for an ADS-B system that complies with § 91.227: “The installed ADS-B Out system has been shown to meet the equipment requirements of 14 CFR § 91.227.”

NOTE: ADS-B Out systems approved per previous versions of AC 20-165 must have any variances, with subsequent revisions of that guidance, resolved through the FAA/manufacturer issue paper process. Such systems do not require revision of existing AFM, AFMS, AOM, POH, Flight Operations Manual (FOM), or equivalent AC 20-165 compliance statements.

NOTE: The requirements in this appendix meet all of the operational, training, and maintenance considerations of AMC 20-24.

(3) Proposed Operations Area. A copy of OpSpec/MSpec B050, Authorized Areas of En Route Operation, Limitations, and Provisions, annotating the authorized en route areas where OpSpec/MSpec/LOA A153 will be used (not applicable to part 91 operators).

(4) Part 91 Operators. A statement that the operator’s pilots have knowledge of current air traffic ADS-B directives for the intended areas of en route operation and will comply with § 91.703.

(5) OpSpec/MSpec/LOA A153. A copy of the completed OpSpec/MSpec/LOA A153, as applicable.

Appendix 1 NOTE: The local Flight Standards Service (AFS) field office will conduct a review of the applicant’s submitted proposal using the OpSpec/MSpec/LOA A153 Application Checklist. When compliance with all applicable requirements has been demonstrated, the PI will issue A153.

Page 5 (and 6)

Appendix 2 APPENDIX 2. ADS-B IN-TRAIL PROCEDURE

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 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 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. Appendix 2, Figure A2-1, 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.

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 A2-1. REDUCTION OF AIRCRAFT SEPARATION MINIMA WITH

IN-TRAIL PROCEDURE

3. ITP TERMINOLOGY.

a. 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.

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.

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 Page 1