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 processor 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 Supplement (AFMS), or POH, which describe the ITP specific:
(a) System description;
(b) Cockpit setup procedures;
Appendix 2
(c) En route procedures;
(d) Communications; and
(e) Non-normal, contingency, and emergency procedures.
(8) Proposed ITP Operations Area. Authorizations 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. Submit applicable portions of proposed ITP-specific dispatch/flight planning training material to include any appropriate updates to the dispatch operations manual, or equivalent, as well 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.
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.
Appendix 2 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
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 [D istance] BEHIND [Aircraft flight identification]” 1 reference aircraft (behind) “ITP [D istance] 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.
Appendix 2 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 BE HIND [Aircraft flight identification]” 1 reference aircraft (behind) “ITP AHEAD OF [Aircraft flight identification]” 2 reference aircraft (both ahead) “ITP BE HIND [Aircraft flight identification] AND BEHIND [Aircraft flight identification]” 2 reference aircraft (both behind) “ITP AHE AD 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.
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 generic term for a satellite navigation system, such as the Global Positioning System (GPS), that provides autonomous worldwide geospatial positioning and may include local or regional augmentations.
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.
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
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.
Appendix 4 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 Web 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.
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 IN Systems and Applications;
(3) 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 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 Surveillance Applications (ASA); and
(8) TSO-C196(), Airborne Supplemental Navigation Sensors for Global Positioning System Equipment Using Aircraft Based Augmentation.
3. INTERNATIONAL PUBLICATION S (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.