ADS, CPDLC, ATC COM, ACARS, AOC, Whaaah? Here's how we keep this straight:
- ADS-B Out — You can think of Automatic Dependent Surveillance - Broadcast Out (ADS-B Out) as a higher tech replacement for your transponder. ADS-B OUT sends your GPS position to air traffic control and other aircraft equipped with ADS-B In. It is much more accurate than a radar blip.
- ADS-B In — You can think of Automatic Dependent Surveillance - Broadcast In (ADS-B In) as a more accurate version of your TCAS. While TCAS aircraft positions shown in your cockpit are approximate, ADS-B In positions are exact.
- ADS-C — You can think of Automatic Dependent Surveillance - Contract (ADS-C) as a replacement for Air Traffic Control radar contact. When you have logged on to an Air Traffic Service Unit with ADS-C, you have agreed to contracts which send information to the ATSU, such as your position, on a regular basis.
- CPDLC — You can think of Controller Pilot Data Link Communications (CPDLC) as a replacement for your HF when oceanic and VHF over some domestic areas. It is far superior to your HF and has distinct advantages over VHF.
- ATC COM, ACARS, AOC — Air Traffic Control Communications (ATC COM) is Honeywell-speak for CPDLC. Aircraft Communication Addressing and Reporting System (ACARS) used to be Airline Communication Addressing and Reporting System and is simply communications through a data service provider and includes your PDC, digital ATIS, and most of your oceanic clearances. Aeronautical Operational Control (AOC) is Gulfstream-speak for ACARS.
Figure: ADS-B Airspace Rule (§91.225) Diagram, from AC 90-114, Figure 1.
[AC 20-165B, ¶1.6] ADS-B is a next generation surveillance technology incorporating both air and ground aspects that provide air traffic control (ATC) with a more accurate picture of the aircraft’s three-dimensional position in the en route, terminal, approach and surface environments. The aircraft provides the airborne portion in the form of a broadcast of its identification, position, altitude, velocity, and other information. The ground portion is comprised of ADS-B ground stations which receive these broadcasts and direct them to ATC automation systems for presentation on a controller’s display. In addition, aircraft equipped with ADS-B In capability can also receive these broadcasts and display the information to improve the pilot’s situation awareness of other traffic.
[AC 20-165B, ¶1.6.1] ADS-B is automatic because no external interrogation is required. It is dependent because it relies on onboard position sources and broadcast transmission systems to provide surveillance information to ATC, and other users.
[AC 20-165B, ¶1.6.3] ADS-B Out refers to an aircraft broadcasting own-ship information. ADS-B In refers to an aircraft’s ability to receive ADS-B information, such as ADS-B messages from other aircraft or Traffic Information Services-Broadcast (TIS-B), Automatic Dependent Surveillance - Rebroadcast (ADS-R), and Flight Information Services Broadcast (FIS-B) from the ground infrastructure.
[AC 90-114, ¶2.2]
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:
(1) 1090 MHz Frequency. The 1090 MHz frequency is associated with current Mode A, C, and S transponder operations.
(2) 978 MHz Frequency. ADS-B equipment 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 information by an aircraft is known as ADS-B IN.
[AC 90-114, ¶2-3]
- 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.
- 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.
- 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.
January 15, 2009, Hudson Bay
[NBAA Article] NAV CANADA implemented the use of Automatic Dependent Surveillance Broadcast (ADS-B Out) on January 15, 2009 at 0500 UTC in the Hudson Bay area between FL350 and FL400 inclusive, to support increased airspace capacity and allow operators access to more efficient routes. Because not all aircraft were equipped with ADS-B avionics per EASA AMC 20-24 by this date, ADS-B based application of surveillance separation standards is being applied tactically to eligible aircraft (those having met certification and qualification standards as well as registered the aircraft's 24 bit ICAO address with NAV CANADA).
More about: Canadian ADS-B Authorization.
December 12, 2013, Australia
[Australia Aeronautical Information Service H09/11 ¶1.5] The regulatory changes effectively establish mandatory aircraft fitment of GNSS and ADS-B avionics equipment for the operation of any aircraft in airspace at or above FL290 after the compliance date of 12 December 2013.
More about: Australian ADS-B Authorization.
December 12, 2013, Singapore
[Singapore AIC 14/10 ¶2.1] On and after 12th December 2013, if an aircraft operates on Airways L642,
M771, N891, M753, L644 and N892 bounded within 073605N 1090045E 040713N 1063543E 041717N 1061247E (MABLI) 044841N 1052247E (DOLOX) 045223N 1041442E (ENREP) 045000N 1034400E thence north along the Singapore FIR Boundary to 070000N 1080000E (see Attachment B) at or above FL290:
a) the aircraft must carry serviceable ADS-B transmitting equipment that has been certified as meeting EASA AMC 20-24, or meets the equipment configuration standards in Appendix XI of Civil Aviation Order 20.18 of the Civil Aviation Safety Authority of Australia; and the aircraft operator must have the relevant operational approval from the State of Registry.
[Singapore AIC 14/10 ¶2.2] Aircraft that does not have the relevant ADS-B operational approval from the State of Registry will be assigned a flight level below FL290.
More about: Singapore ADS-B Authorization.
December 7, 2017, Eurocontrol
[NBAA Article] As a result of Europe’s Single European Sky ATM Research (SESAR) program, the European Commission has adopted new rules to require that aircraft be equipped with “ADS-B out” technology. By December 7, 2017, aircraft operating in the European Union must be retrofitted with ADS-B out. All newly manufactured aircraft with a certificate of airworthiness issued on or after January 8, 2015, must also be equipped with this technology.
January 1, 2020, United States
[14 CFR 91 §91.225]
(a) After January 1, 2020, and unless otherwise authorized by ATC, no person may operate an aircraft in Class A airspace unless the aircraft has equipment installed that—
(1) Meets the requirements in 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); and
(2) Meets the requirements of §91.227.
(b) After January 1, 2020, and unless otherwise authorized by ATC, no person may operate an aircraft below 18,000 feet MSL and in airspace described in paragraph (d) of this section unless the aircraft has equipment installed that—
(1) Meets the requirements in—
(i) TSO-C166b; or
(ii) TSO-C154c, Universal Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on the Frequency of 978 MHz;
(2) Meets the requirements of §91.227.
(c) Operators with equipment installed with an approved deviation under §21.618 of this chapter also are in compliance with this section.
(d) After January 1, 2020, and unless otherwise authorized by ATC, no person may operate an aircraft in the following airspace unless the aircraft has equipment installed that meets the requirements in paragraph (b) of this section:
(1) Class B and Class C airspace areas;
(2) Except as provided for in paragraph (e) of this section, within 30 nautical miles of an airport listed in appendix D, section 1 to this part from the surface upward to 10,000 feet MSL;
(3) Above the ceiling and within the lateral boundaries of a Class B or Class C airspace area designated for an airport upward to 10,000 feet MSL;
(4) Except as provided in paragraph (e) of this section, Class E airspace within the 48 contiguous 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; and
(5) 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 nautical miles.
You will need ADS-B Out in the United States starting January 1, 2020 in most airspace:
- Class A
- Class B
- Class C
- Within 30 nm of Appendix D airports
- Class E above 10,000' MSL except below 2,500' AGL, and in the Gulf of Mexico above 3,000' MSL 12 nm beyond the shoreline.
[Information for Operators (InFO) 13009] The following information identifies FAA approval requirements for U.S. aircraft operators in foreign ADS-B airspace: Australia: A353 not required. Approved ADS-B avionics will be required on, and from, December 12, 2013, for all operations at or above flight level (FL) 290. Refer to Australian Civil Aviation Safety Authority Australia Advisory Circular 21-45(1), Airworthiness Approval of Airborne Automatic Dependent Surveillance Broadcast Equipment, for guidance on approved ADS-B equipment used in Australia.
[Australia Advisory Circular 21-45(1) ¶10.1.1] CAO 82.1 Paragraph 5.8, CAO 82.3 Paragraph 10.8 and CAO 82.5 Paragraph 10.8 detail the requirements for ADS-B that foreign registered aircraft must comply with if intending to utilise ADS-B services operations within Australian FIR.
[Australian Civil Aviation Order 82.3, ¶10.8] The operator of a foreign registered aircraft must ensure that it complies with the requirements (Directions) in Appendices 6 and 6A. The definitions in Appendix 6 also apply for Appendices 6A and 7.
[Australian Civil Aviation Order 82.3, Appendix 6 and 7] Directions relating to carriage and use of automatic dependent surveillance – broadcast equipment
- FAA means the Federal Aviation Administration of the United States.
- ADS-B transmitting equipment must be of a type that: (a) is authorised by: (i) the FAA in accordance with TSO-C166 as in force on 20 September 2004, or a later version as in force from time to time; or (ii) CASA, in writing
The Australians have 3 regulations, depending on if you are flying charter (Australian Civil Aviation Order 82.1), small cabin (Australian Civil Aviation Order 82.3), or large cabin (Australian Civil Aviation Order 82.5) aircraft. Each of these say if the U.S. FAA says you are good to go, you are good to go.
[Information for Operators (InFO) 13009] The following information identifies FAA approval requirements for U.S. aircraft operators in foreign ADS-B airspace: Canada: A353 conditionally required. Authorization, per A353, is required only when an operator seeks operational benefit from ADS-B Out equipage in the airspace defined in Nav Canada Aeronautical Information Circulars (AICs) 31/11 and 44/11.
[Nav Canada Aeronautical Information Circular 31/11] Domestic operators and those foreign operators holding a Foreign Air Carrier Operations Certificate are required to apply to Transport Canada for Operations Specifications 609 or 610 to be eligible to have a separation standard applied based on ADS-B Out. Transport Canada has provided guidance in Advisory Circular AC700-009 revision 2 as to how operators can achieve this specification. Operators who do not fall into these categories are required to provide NAV CANADA with proof from the civil aviation authority of their aircraft’s state of registry of compliance with the European Aviation Safety Agency’s (EASA) Acceptable Means of Compliance (AMC) 20-24. In addition, in all cases operators must complete an aircraft equipment survey and provide NAV CANADA with each aircraft’s unique 24-bit transponder address in order to be entered onto the list of eligible aircraft.
[Nav Canada Aeronautical Information Circular 44/11]Operators must meet the conditions of operational specification No. 609 or No. 610, as appropriate, outlined in Transport Canada, Advisory Circular (AC) 700-009, Issue No. 2. Operators must also complete an aircraft equipment survey and provide NAV CANADA with each aircraft’s unique 24-bit transponder address in order to be entered onto the list of eligible aircraft.
[Transport Canada AC 700-009 ¶6.2] A foreign air operator must meet the conditions of operational specification No. 610, provided in Appendix B of this document, to obtain operational approval for ADS-B operations. The conditions are as follows:
(a) the aircraft, the equipment and the installation must:
(i) meet the airworthiness requirements of the State of the Foreign Air Operator; and
(ii) meet the certification considerations of the European Aviation Safety Agency (EASA) AMC 20-24 ―Certification Considerations for the Enhanced ATS in Non-Radar Areas using ADS-B Surveillance (ADS-B-NRA) Application.
(b) Company Operations Manual— The air operator must establish procedures in its Company Operations Manual for the guidance of its personnel and any other procedures related to ADS-B that are necessary for safe operations. These procedures must include at least a system description, the operational aspects described in document EASA AMC 20-24, operational and contingency procedures, and training elements for use of the ADS-B-NRA application.
(c) Training—The air operator must provide training to each flight crew member involved with ADS-B operations that address at least the items listed at sections 10.3.2 and 10.4 of EASA document AMC 20-24.
[Information for Operators (InFO) 13009] The following information identifies FAA approval requirements for U.S. aircraft operators in foreign ADS-B airspace: Hong Kong: A353 required. Authorization, per A353, is required for all U.S. aircraft operators flying over performance-based navigation routes L642 or M771 at or above FL290 within Hong Kong flight information region (FIR) on and after December 12, 2013. Additionally, A353 will be required on and after December 31, 2014 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 Hong Kong AIC 09/11, Automatic Dependent Surveillance Broadcast (ADS-B) Out Operations.
[Hong Kong AIRAC AIP Supplement A11/14, ¶4] The aircraft operator must have the relevant ADS-B operational approval from the State of Registry.
[Information for Operators (InFO) 13009] The following information identifies FAA approval requirements for U.S. aircraft operators in foreign ADS-B airspace: Singapore: A353 required. Authorization, per A353, is required for U.S. aircraft operators operating on ATS routes N891, M753, L642, M771, L644, and N892 at FL290 and above within the Singapore FIR on and after December 12, 2013. For additional information regarding ADS-B operations within the Singapore FIR, refer to Singapore AIC 14/10, Introduction of Automatic Dependent Surveillance Broadcast (ADS-B) Out Services within parts of the Singapore FIR.
[Singapore AIP Supplement 254 ¶2.1] The aircraft must carry serviceable ADS-B transmitting equipment that has been certified as meeting EASA AMC 20-24, or meets the equipment configuration standards in Appendix XI of Civil Aviation Order 20.18 of the Civil Aviation Safety Authority of Australia; and the aircraft operator must have the relevant operational approval from the State of Registry.
[AC 90-114 Ch. 1 ¶ 1-3.b.] There is no authorization required by the Federal Aviation Administration (FAA) to conduct ADS-B OUT operations in the airspace defined by 14 CFR §91.225 (U.S.-designated airspace).
Outside of U.S.-Designated Airspace
[AC 90-114 App. 1. ¶2.] 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.
Instructions for how to request an authorization, LOA or OpSpec, are contained in AC 90-114, Appendix 1.
EASA (and much of the world)
European Aviation Safety Agency (EASA) Acceptable Means of Compliance (AMC) 20-24 ¶9 provides several methods to demonstrate ADS-B equipment qualification. In the G450, we have a specific statement in ASC 079.
U.S. equipment requirements are contained in Advisory Circular 20-165B.
[AC 90-114 ¶ 1-3.c.]
- 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.
[14 CFR 91 §91.225]
(f) Each person operating an aircraft equipped with ADS-B Out must operate this equipment in the transmit mode at all times.
(g) Requests for ATC authorized deviations from the requirements of this section must be made to the ATC facility having jurisdiction over the concerned airspace within the time periods specified as follows:
(1) For operation of an aircraft with an inoperative ADS-B Out, to the airport of ultimate destination, including any intermediate stops, or to proceed to a place where suitable repairs can be made or both, the request may be made at any time.
(2) For operation of an aircraft that is not equipped with ADS-B Out, the request must be made at least 1 hour before the proposed operation.
[AC 90-114 Ch. 1 ¶ 4-4.] When operating aircraft equipped with ADS-B OUT, operators should indicate their ADS-B capability on the flight plan as “RMK/ADSB.”
[AC 90-114 Appendix 1, ¶2.c.(7)] 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);
- Handling of data source errors (e.g., discrepancies between navigation data sources); and
- Incident reporting procedures.
The following are the applicable training items as required for a G450.
ADS-B operating procedures
[Gulfstream ADS-B Data Package, pg. 23]
- ADS-B operating procedures consist of checking cockpit indications that the system is operating in conjunction with the transponder and a valid GPS signal is availalbe to the FMS.
- The transponder and associated ADS-B out should be selected ON at all times including ground operation unless instructed otherwise by ATC.
Figure: ADS-B MCDU 1, from Gulfstream ADS-B Data Package, pg. 24.
Figure: ADS-B MCDU 1, from Gulfstream ADS-B Data Package, pg. 25.
[Gulfstream ADS-B Data Package, pg. 26]
- Review international NOTAMS and AIM for airspace regions where the requirement for ADS-B out is in effect.
- Have a plan for alternate routes or altitudes should ADS-B out become inoperative.
[Gulfstream ADS-B Data Package, pg. 26] ADS-B is a category A repair item - may be inoperative provided:
- Operations do not require its use, and
- Repairs are made before completion of next heavy maintenance visit.
[Gulfstream ADS-B Data Package, pg. 26] Flight crews should use authorized checklists and flight manual procedures while operating ADS-B out.
ADS-B phraseology applicable to specific regions of operation (see Table 1, Canadian-Specific Surveillance Phraseology, and Table 2, Australian-Specific Surveillance Phraseology)
Figure: Canadian ADS-B Phraseology, from AC 90-114, Appendix 1, Table 1.
Figure: Australian ADS-B Phraseology, from AC 90-114, Appendix 1, Table 2.
ADS-B system operation, including normal/abnormal procedures
Figure: ADS-B CAS Message, from Gulfstream ADS-B Data Package, pg. 28.
[Gulfstream ADS-B Data Package, pg. 27] Normal operation of ADS-B out is transparent to the flight crew and is as previously described. System malfunctions are indicated by a CAS message and amber indication on the TCAS page. Failure of both transponders or lack of a usable GPS signal can cause ADS-B system failure - notify ATC of any suspected ADS-B failure or degradation (i.e. Blue "ADS-B fail" CAS message or amber indication on TCAS page).
Correct entry of ICAO aircraft ID as applicable to the flight
Figure: ADS-B Flight Plan Entries, from Gulfstream ADS-B Data Package, pg. 31.
[Gulfstream ADS-B Data Package, pg. 30] Ensure that the flight identification entered on the ICAO flight plan matches the identification transmitted by ADS-B as shown on the TCAS page.
- Enter the correct ADS-C code on the ICAO flight plan.
- In block 18 enter the code for RTCA DO 260B compliant ADS-B
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)
[Gulfstream ADS-B Data Package, pg. 32] If the flight crew experiences an emergency situation and changes the transponder code to 7700, 7600, or 7500, the ADS-B data transmitted via the transponder will include a digital value corresponding to the selected emergency code. This digit appended to the code will alert ATC to the need for special handling and prompt communications to confirm the assistance needed.
Handling of data source errors (e.g., discrepancies between navigation data sources)
[Gulfstream ADS-B Data Package, pg. 33] ADS-B aircraft position information is provided by the GPS. If the satellite constellation is degraded, the ADS-B transmitted position may be outside of acceptable limits - this condition will not be detectable by the flight crew, but the ADS-B ground station will be notified of the degradation.
Incident reporting procedures.
Figure: ADS-B Out Non-compliance and/or Manfunction Report, from Gulfstream ADS-B Data Package, pg. 39.
[Gulfstream ADS-B Data Package, pg. 34]
- The flight crew must report the failure of ADS-B out to ATC as soon as possible - expect possible change of altitude and or routing depending upon other traffic and capabilty of ATC.
- After landing note ADS-B system fault in aircraft maintenance log. Review MEL requirements if repairs cannot be made prior to the next flight.
Gulfstream provides an ADS-B Out Non-compliance / Malfunction Report.
Reducing In-trail Spacing
Figure: Reduction of Aircraft Separation Minima with ITP, from AC 90-114, Appendix 2, Figure 1.
Twenty years ago, without everyone using GPS, I would say reducing in-trail spacing was nuts. Now? If it means I get my altitude when I want it, bring it on. But you can't do this without ADS-B Out. You are going to need approval before you can do this.
[AC 90-114, Appendix 2, ¶2.] 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.
- 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.
- 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.
[AC 90-114, Appendix 2, ¶2.] The ITP concept is based on the aircraft satisfying specific initial conditions, and the flightcrew promptly and correctly executing the requested procedure once approved. The initial conditions are the ITP speed/distance criteria, the relative altitude criteria, the similar track criteria, the closing Mach differential, as well as accuracy and integrity of the ADS-B data transmitted from participating aircraft. . . . The procedure further requires that the ITP aircraft maintain constant Mach, and climb or descend at a minimum of 300 feet per minute (fpm) during the maneuver. With these criteria, an ITP aircraft should never come closer than the 10 nautical mile (NM) separation minimum to a reference aircraft while passing through their altitude(s).
- ITP Distance and Groundspeed Differential Criteria. The initial distance criteria values, 15 NM and 20 NM, were selected so that, when an FL change at 300 fpm and constant Mach number is maintained with the respective maximum 20 or 30 knot closing ground speed differential, the distance between the aircraft should not become less than the ITP minimum separation of 10 NM.
- Relative Altitude Criteria. The reference aircraft may not be more than 2,000 feet above or below the ITP aircraft.
- Similar Track Criteria. The ITP aircraft and any reference aircraft must be on similar tracks. Similar tracks are defined here as less than 45 degrees from one another. (See [the figure], Similar Track).
- 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).
- 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.
Figure: Similar Track, from AC 90-114, Appendix 2, Figure 3.
Portions of this page can be found in the book International Flight Operations, Part V, Chapter 2.
14 CFR 91, Title 14: Aeronautics and Space, General Operating and Flight Rules, Federal Aviation Administration, Department of Transportation
Advisory Circular 20-165B, Airworthiness Approval of Automatic Dependent Surveillance - Broadcast (ADS-B) Out Systems, 12/07/15, U.S. Department of Transportation
Advisory Circular 90-114, Automatic Dependent Surveillance-Broadcast (ADS-B) Operations, 9/21/12, U.S. Department of Transportation
Australia Advisory Circular 21-45(1), Airworthiness Approval of Airborne Automatic Dependent Surveillance Broadcast Equipment, February 2012, Australian Government Civil Aviation Safety Authority
Australia Aeronautical Information Service H09/11, Transition to Satellite Technology for Navigation and Surveillance, 15 Jun 11
Australian Civil Aviation Order 82.1, Conditions on Air Operators' Certificates authorising charter and aerial work operations, 15 February 2012, Australian Government Civil Aviation Safety Authority
Australian Civil Aviation Order 82.3, Conditions on Air Operators' Certificates authorising regular public transport operations other than high capacity aircraft, 27 June 2011, Australian Government Civil Aviation Safety Authority
Australian Civil Aviation Order 82.5, Conditions on Air Operators' Certificates authorising regular public transport operations in high capacity aircraft, 27 June 2011, Australian Government Civil Aviation Safety Authority
European Aviation Safety Agency (EASA) Acceptable Means of Compliance (AMC) 20-24, Certification Considerations for the Enhance ATS in Non-Radar Areas using ADS-B Surveillance (ADS-B-NRA) Application via 1090 MHz Extended Squitter, February 5, 2008
FAA Order 8900, Vol 3, Ch. 18, A353, 10/17/13
Fiji Aeronautical Information Circular (AIC) 04/11 Operation of Foreign Registered Aircraft in Fiji, 28 July 2011
Gulfstream G350 G450 G500 G550 Operator Data Package for Gulfstream GXXX Aircraft Automatic Dependent Surverillance Broadcast (ADS-B) Operations Outside of U.S. Designated Airspace - OPSEC/MSPEC/LOA A353, October 10, 2013
Gulfstream G450 Aircraft Operating Manual, Revision 35, April 30, 2013.
Gulfstream G450 Aircraft Service Change Number 079, Automatic Dependent Surveillance Broadcast (ADS-B) out Installation, April 12, 2013
Hong Kong AIRAC AIP Supplement A11/14, Automatic Dependent Surveillance Broadcast (ADS-B) Out Operations, 29 August 2014, Hong Kong Special Administrative Region, People's Republic of China
Information for Operators (InFO) 13009 Operations Specification (OpSpec)/Management Specification (MSpec)/Letter of Agreement (LOA) Paragraph A353, Automatic Dependent Surveillance-Broadcast (ADS-B) Operations Outside of U.S. Designated Airspace, 6/17/13, U.S. Department of Transportation
Nav Canada Aeronautical Information Circular 31/11, Air Traffic Services Associated with Automatic Dependent Surveillance-Broadcast Out Surveillance (Hudson Bay and Minto Sectors), 20 Oct 11
Nav Canada Aeronautical Information Circular 44/11, Air Traffic Services Associated with Automatic Dependent Surveillance-Broadcast Service in the Gander Oceanic Control Area, 15 Dec 11
Republic of China Aeronautical Information Circular (AIC) 02/12, Introduction of Automatic Dependent Surveillance Broadcast (ADS-B) Out Service within Taipei FIR, 17 May 2012
Singapore AIP Supplement 254, Implementation of Automatic Dependent Surveillance Broadcast (ADS-B) Out Service Within Part of the Singapore FIR, 6th November 2013, Civil Aviation Authority of Singapore
Transport Canada Advisory Circular 700-009, Automatic Dependent Surveillance - Broadcast, 2011-03-11, Transport Canada Standards
Vietnam Aeronautical Information Circular (AIC) A03/13, Implementation of Automatic Dependent Surveillance Broadcast (ADS-B) Within Ho Chi Minh FIR, 20 Jun 2013