AC 91-70C

Historical

Advisory circular · Oceanic and Remote Continental Airspace Operations

A newer version is currentThis is a historical version. AC 91-70D is the version in force, approved April 3, 2025.
Approved
October 4, 2023
Last reviewed
August 2, 2024
Family
AC 91-70 · 6 versions
Revision
C
14 CFR parts
91, 119, 121, 125, 135

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 22, 2025.

U.S. Department of Transportation Federal Aviation Administration Advisory Circular Subject: Oceanic and Remote Continental Airspace Operations Date: 10/4/23 AC No: 91-70C Initiated by: AFS-400 Change:

This advisory circular (AC) contains both general information and detailed guidance for operators planning flights in oceanic and remote continental airspace. This includes Performance-based Navigation (PBN) and Special Areas of Operation (SAO). The Federal Aviation Administration (FAA) revised this AC to focus on the evolving operations in oceanic and remote continental airspace. This AC is laid out in a building block format, beginning with foundational information, followed by information on the training, authorizations, and equipment required to operate most efficiently in this airspace, and finishing with flight planning, flight execution, and contingency operations guidance. Our goal is to provide you with a template to guide you through planning and executing flight operations through oceanic and remote continental airspace. Information related to international operations in specific locales continues to be available in the North Atlantic (NAT) Resource Guide for United States Operators; the West Atlantic, Gulf of Mexico, and Caribbean Resource Guide for U.S. Operators; a nd the Pacific Resource Guide for U.S. Operators. These online resource guides, along with Notices to Air Missions (NOTAM) and FAA International Notices, provide the most current information available to pilots, aircraft dispatchers, and other operational control personnel preparing for oceanic and international operations. We have also included hyperlinks to many documents, available free or for purchase. While we carefully checked at the time of publication that information included in this AC is current, oceanic and remote continental airspace operations are constantly evolving, and it is incumbent on you, the operators, to ensure you are flying with current information.

This AC neithe r is mandatory nor does it constitute a regulation. When this AC uses mandatory language (e.g., “must” or “may not”), it is quoting or paraphrasing a regulatory requirement or prohibition. When this AC uses permissive language (e.g., “should” or “may”), it describes an acceptable means, but not the only means, of conducting that aspect of operations in oceanic and remote continental airspace. However, if you use the means described in the AC, you must follow them in all important respects.

Wesl ey L. Mooty Acting Deputy Executive Director, Flight Standards Service

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CONTENTS Paragraph Page

Chapter 1. General1-1

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

1.2 Audience1-1

1.3 Where You Can Find This AC1-1

1.4 What This AC Cancels1-1

1.5 Fundamental Changes From Previous Edition1-1

1.6 Related Title 14 Of The Code Of Federal Regulations (14 CFR) Parts1-1

1.7 Related Reading Material (Current Editions)1-2

1.8 AC Feedback Form1-3

Chapter 2. Background Information for Operations in Oceanic and R emote

Continental Airspace2-1

2.1 ICAO: Its Relationship to U.S. Aviation2-1

2.2 ICAO Annexes2-1

2.3 Applicability of U.S. and International Regulations2-3

2.4 ICAO Guidance Documents and Reference Material2-5

2.5 Authorization to Operate in Oceanic/Remote Continental Airspace and Special

Areas of Operation (SAO)2-9

2.6 Authorization Process2-9

2.7 Web-Based Operations Safety System (WebOPSS)2-10

Chapter 3. Pilot Qualification and Training Guidance for Oceanic and Remote Continental

Airspace Operations3-1

3.1 Training Requirements for Oceanic and Remote Continental Airspace

Operations3-1

Chapter 4. Communications, Navigation, and S urveillance Systems Guidance for

Operations in Oceanic and Remote Continental Airspace4-1

4.1 Communications, Navigation, and Surveillance Improvements—Impact

on ATS4-1

4.2 Performance-Based Operations4-1

4.3 Voice Communications in Oceanic Airspace4-3

4.4 CPDLC and Automatic Dependent Surveillance-Contract (ADS-C)4-7

4.5 Data Link Systems—Operational Authorization to Use4-9

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4.6 ATC in Oceanic and Remote Continental Airspace4-10

4.7 Special Use Airspace (SUA)4-12

4.8 Air Defense Identification Zones (ADIZ)4-13

4.9 World Geodetic System 1984 (WGS 84)4-13

Chapter 5. Flight Planning Guidance for International and Oceanic and Remote C

ontinental Airspace Operations5-1

5.1 Lead Time Requirements5-1

5.2 Preparing an Itinerary5-1

5.3 Crew Fatigue5-4

5.4 Required Paperwork/Documentation5-4

5.5 Entry to Foreign Airspace—Flight Plan vs. Formal Advance Permission5-7

5.6 Managing Risk in Oceanic and Remote Continental Airspace Operations5-7

5.7 Weather Forecasts and Other Meteorological Planning5-7

5.8 FAA International Notices Website5-8

5.9 ETOPS5-8

5.10 Polar Operations5-9

5.11 Areas With Limited or No ATS (Also Called “No FIR” Areas)5-9

5.12 Rotorcraft Operations5-10

Chapter 6. Flight Execution Guidance for Operations in Oceanic and Remote C

ontinental Airspace6-1

6.1 General Information6-1

6.2 Flight Plan6-5

6.3 Aircraft Preflight Guidance6-6

6.4 En Route Guidance6-12

Chapter 7. In-F light Contingency Guidance for Operations in Oceanic Airspace7-1

7.1 Contingency Procedures: When They May Be Needed7-1

7.2 Choosing The Correct Contingency Procedure7-1

7.3 Altimetry and/or Navigation Degradation7-2

7.4 Lost Communications Procedures7-2

7.5 Normal Aircraft Tracking7-3

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Appendix A. Abbreviations a nd DefinitionsA-1

Appendix B. Sp ecial Areas of Operation and OpSpecs/MSpecs/LOAsB-1

Appendix C. Unusual Weather ActivityC-1

A

ppendix D. Sam ple Oceanic ChecklistD-1

Appendix E. IAT A In-Flight Broadcast ProcedureE-1

Appendix F. Sp ecial Procedures for In-Flight Contingencies in Oceanic AirspaceF-1

Appendix G. Sugge sted Subjects for Inclusion in Oceanic and International Procedures

and/or an Operations ManualG-1

List of Figures Fi

gure 4-1. Sample CPDLC Route Uplinks4-9

Figure 6-1. Sa mple Plotting Chart6-8

Figure C-1. IC AO Volcanic Ash Advisory CentersC-1

Figure C-2. Ex ample of a National Oceanic and Atmospheric Administration Scales

Activity ReportC-3

Figure E-1. Ma p of IFBP Area of ApplicabilityE-2

Figure F-1. Sp ecial Procedures for In-Flight Contingencies in Oceanic Airspace

(Non-Weather)F-1

Figure F-2. Sp ecial Procedures for In-Flight Weather ContingenciesF-6

List of Tables Tab

le 6-1. Examples of Incorrectly Applied Conditional Clearances6-2

Table B-1. SAO -Related OpSpecs/MSpecs/LOAsB-1

Table B-2. Ocean ic and Remote/General En Route OpSpecs/MSpecs/LOAsB-2

Table F-1. Al titude Offset When Denied Clearance to Deviate 9.3 km (5.0 NM) or More

(5 NM Procedures)F-7

1-1 CHAPTER 1. GENERAL

1.1 Purpose of This Advisory Circular (AC). The Federal Aviation Administration (FAA) (“we”) developed this AC to provide general information and guidance for certificated and General Aviation (GA) operators (“you”) planning flights in oceanic and remote continental airspace. This guidance includes the authorizations you may need for operations in such airspace. The contents of this document do not have the force and effect of law and are not meant to bind the public in any way, and the document is intended only to provide information to the public regarding existing requirements under the law or agency policies.

1.2 Audience. We wrote this AC primarily for operators who do not have experience with flying in oceanic and remote continental airspace, to assist in developing their own procedures. We also wrote this AC for GA pilots who do not fly regularly in oceanic and remote continental airspace and need a refresher in planning and executing such a flight.

Most certificated operators have company procedures for operations in oceanic and remote continental airspace. Those procedures have been accepted by FAA inspectors and conform to all relevant regulations and guidance. If you are working for one of these operators, this AC may serve to reinforce your company procedures.

1.3 Where You Can Find This AC. You can find this AC on the FAA’s website at https://www.faa.gov/regulations_policies/advisory_circulars.

1.4 What This AC Cancels. AC 91-70B CHG 1, Oceanic and Remote Continental Operations, dated February 1, 2019, is canceled.

1.5 Fundamental Changes From Previous Edition. This revision of AC 91-70 contains numerous changes from the previous edition, many of which clarify or amplify information provided earlier. Operators should review this revised AC in its entirety. We have added information on the use of Satellite Voice (SATVOICE) communications, Controller-Pilot Data Link Communication (CPDLC), and space-based Automatic Dependent Surveillance-Broadcast (ADS-B), as well as updated information on common causes of pilot deviations and re-emphasized the importance of accurate flight plan equipment and capability codes. We updated the contingency procedures, in line with International Civil Aviation Organization (ICAO) changes, and explain the requirements for oceanic authorizations. Finally, we provide updated links to the most current sources of international material.

1.6 Related Title 14 of the Code of Federal Regulations (14 CFR) Parts.

• Part 91, §§ 91.1 through 91.21, 91.101 through 91.143, 91.151 through 91.159,

91.167 through 91.193, 91.203, 91.205, 91.209 through 91.217, 91.221, 91.225,

91.227, 91.303 through 91.319, 91.323, 91.509, 91.511, 91.605, 91.609, 91.703 through 91.715, 91.903, 91.1039, and 91.1073; and Appendix G.

• Part 119, §§ 119.5, 119.49, 119.59, and 119.63.

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• Part 121, §§ 121.11, 121.101, 121.121, 121.163, 121.339, 121.351, 121.353, 121.355,

121.401, 121.415, 121.427, and 121.445; and Appendix G.

• Part 125, §§ 125.23, 125.45, 125.51, 125.203, 125.209, 125.296, and 125.363.

• Part 135, §§ 135.3, 135.43, 135.145, 135.165, 135.167, 135.183, 135.213, 135.323,

135.329, 135.351, 135.364, and 135.381; and Appendix G.

1.7 Related Reading Material (current editions).

1.7.1 RT CA Documents . Available for purchase on the RTCA website at https://www.rtca.org/standards.

1. RTCA/DO-258/ED-100, Interoperability Requirements for ATS Applications Using ARINC 622 Data Communications.

2. RTCA/DO-260/ED-102, Minimum Operational Performance Standards (MOPS) for 1090 MHz Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic Information Services – Broadcast (TIS-B).

3. RTCA/DO-306/ED-122, Safety and Performance Standard for Air Traffic Data Link Services in Oceanic and Remote Airspace (Oceanic SPR Standard).

4. RTCA/DO-350/ED-228, Safety and Performance Requirements Standard for Baseline 2 ATS Data Communications (Baseline 2 SPR Standard).

1.7.2 F AA Technical Standard Orders (TSO) .

1. TSO-C115, Flight Management System (FMS) Using Multi-Sensor Inputs.

2. TSO-C145, Airborne Navigation Sensors Using The Global Positioning System Augmented by the Satellite Based Augmentation System (SBAS).

3. TSO- C146, Stand-Alone Airborne Navigation Equipment Using The Global Positioning System Augmented by the Satellite Based Augmentation System (SBAS).

4. TSO- C196, Airborne Supplemental Navigation Sensors for Global Positioning System Equipment Using Aircraft-Based Augmentation.

1.7.3 FAA ACs.

1. AC 20-138, Airworthiness Approval of Positioning and Navigation Systems.

2. AC 20-140, Guidelines for Design Approval of Aircraft Data Link Communication Systems Supporting Air Traffic Services (ATS).

3. AC 20-150, Airworthiness Approval of Satellite Voice (SATVOICE) Equipment Supporting Air Traffic Service (ATS) Communication.

4. AC 90-80, Approval of Offshore Standard Approach Procedures, Airborne Radar Approaches, and Helicopter En Route Descent Areas.

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5. AC 90-96 , Approval of U.S. Operators and Aircraft to Operate Under Instrument Flight Rules (IFR) in European Airspace Designated for Basic Area Navigation (B-RNAV) and Precision Area Navigation (P-RNAV).

6. AC 90- 105, Approval Guidance for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System and in Oceanic and Remote Continental Airspace.

7. AC 90- 114, Automatic Dependent Surveillance -Br oadcast Operations.

8. AC 90-117, Data Link Communications.

9. AC 91-85, Authorization of Aircraft and Operators for Flight in Reduced Vertical Separation Minimum (RVSM) Airspace.

10. AC 91- 92, Pilot’s Guide to a Preflight Briefing .

11. AC 120-42, Extended Operations (ETOPS and Polar Operations).

12. AC 120-100, Basics of Aviation Fatigue.

13. AC 120-103, Fatigue Risk Management Systems for Aviation Safety.

14. AC 121-31, Flight Crew Sleeping Quarters and Rest Facilities.

15. AC 135-42, Extended Operations (ETOPS) and Operations in the North Polar Area.

1.7.4 FAA IFR Enroute Aeronautical Planning Charts. These charts are available at https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/ifr.

1. North Atlantic Route Chart.

2. North Pacific Route Chart.

3. Western Atlantic Route System Chart.

1.8 AC Feedback Form. For your convenience, the AC Feedback Form is the last page of this AC. Note any deficiencies found, clarifications needed, or suggested improvements regarding the contents of this AC on the AC Feedback Form.

2-1 CHAPTER 2. BACKGROUND INFORMATION FOR OPERATIONS IN OCEANIC

AND REMOTE CONTINENTAL AIRSPACE

2.1 ICAO and Its Relationship to U.S. Aviation. The United States is a Contracting State to the Convention on International Aviation (Chicago Convention) and an ICAO Member State and has fully supported the organization’s goals from its inception. ICAO works to achieve the highest level of standards and procedures for aircraft, personnel, airways, and aviation services throughout the world. ICAO oversees the international standards ascribed to by its more than 190 Member States for navigation facilities, airports, weather, and radio services. Through active support and participation in ICAO, the FAA strives to improve worldwide safety standards and procedures. ICAO’s strategic objectives are to continue to establish and maintain Standards and Recommended Practices (SARPs) for the safe and orderly development of international aviation. The 19 Annexes to the Chicago Convention (ICAO Annexes) contain more than 10,000 adopted SARPs.

Note: ICAO Member States are obligated to “collaborate in securing the highest practicable degree of uniformity in regulations” and generally achieve this by complying with the SARPs contained in the 19 Annexes and supporting ICAO documents such as ICAO Doc 4444, Procedures for Air Navigation Services— Air Traffic Management, and ICAO Doc 7030, Regional Supplementary Procedures.

States notify ICAO of their “differences” with SARPs and publish them in their Aeronautical Information Publication (AIP).

2.2 IC AO Annexes. Find all ICAO Annexes at the ICAO store at https://store.icao.int.

2.2.1 Annex 1, Personnel Licensing. Provides information on licensing of flightcrews, air traffic controllers, and aircraft maintenance personnel, including medical standards for flightcrews and air traffic controllers.

2.2.2 Annex 2, Rules of the Air. Contains visual flight rules (VFR) and instrument flight rules (IFR) for all operators.

2.2.3 Annex 3, Meteorological Service for International Air Navigation. Provides for meteorological services for international air navigation and reporting of meteorological observations from aircraft.

2.2.4 Annex 4, Aeronautical Charts. Contains specifications for aeronautical charts used in international aviation.

2.2.5 Annex 5, U nits of Measurement to be Used in Air and Ground Operations. Lists dimensional systems used in air and ground operations.

2.2.6 Annex 6, Op eration of Aircraft (3 Parts). Specifies minimum standards for below-listed operations throughout the world:

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1. Part I, International Commercial Air Transport—Aeroplanes.

2. Part II, International General Aviation—Aeroplanes.

3. Part III, International Operations—Helicopters.

2.2.7 Annex 7, Aircraft Nationality and Registration Marks. Specifies requirements for registration and identification of aircraft.

2.2.8 A nnex 8, Airworthiness of Aircraft. Specifies uniform procedures for certification and inspection of aircraft.

2.2.9 A nnex 9, Facilitation. Provides for the standardization and simplification of border-crossing formalities.

2.2.10 A nnex 10, Aeronautical Telecommunications:

1. Volume I, Radio Navigation Aids. Provides for standardizing communications equipment and systems.

2. Volume II, Communication Procedures including those with PANS status.

Standardizes communications procedures.

3. Volume III, Communication Systems. Standardizes communications systems.

4. Volume IV, Surveillance and Collision Avoidance Systems. Standardizes surveillance radar and collision avoidance.

5. Volume V, Aeronautical Radio Frequency Spectrum Utilization. Standardizes aeronautical radio spectrum utilization.

2.2.11 Annex 11, Air Traffic Services. Includes information on establishing and operating air traffic control (ATC), flight information, and alerting services.

2.2.12 A nnex 12, Search and Rescue. Provides information on organization and operation of facilities and services necessary for Search and Rescue (SAR).

2.2.13 A nnex 13, Aircraft Accident and Incident Investigation. Provides for uniformity in notifying, investigating, and reporting on aircraft accidents.

2.2.14 A nnex 14, Aerodromes:

1. Volume I, Aerodrome Design and Operations. Contains specifications for the design and equipment of aerodromes.

2. Volume II, Heliports. Contains specifications for the design and equipment of heliports.

2.2.15 Annex 15, Aeronautical Information Services. Includes methods for collecting and disseminating aeronautical information required for flight operations.

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2.2.16 A nnex 16, Environmental Protection:

1. Volume I, Aircraft Noise. Contains specifications for aircraft noise certification, noise monitoring, and noise exposure units for land-use planning.

2. Volume II, Aircraft Engine Emissions. Contains specifications for aircraft engine emissions.

3. Volume III, Aeroplane CO2 Emissions.

4. Volume IV, Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA).

2.2.17 A nnex 17, Security. Specifies methods for safeguarding international civil aviation against unlawful acts of interference.

2.2.18 Annex 18, The Safe Transport of Dangerous Goods by Air. Contains specifications for labeling, packing, and shipping dangerous cargo.

2.2.19 Annex 19, Safety Management. Describes Safety Management System (SMS) development, regulatory framework, and supporting guidance.

2.3 A pplicabilit y of U.S. and International Regulations.

2.3.1 FAA regulations relating to certification, airworthiness, licensing, and certain operational aspects (e.g., operational control, communication and navigation equipment, and Extended Operations (ETOPS)), are applicable to U.S. operators wherever they fly. Some of these regulations are fundamental to oceanic operations:

2.3.1.1 Title 14 CFR part 91, § 91.511 (applicable to part 91 subpart F), deals with “overwater” operations which are more than 30 minutes or 100 nautical miles (NM) from the nearest shore.

Note: S ection 91.511(b) notes that a unit is “independent if the function of any part of it does not depend on the functioning of any part of another receiver or electronic navigation unit.”

2.3.1.1.1 For such operations, two independent long-range navigation systems (LRNS) are required, except in an area defined by coordinates in § 91.511(f), where only one LRNS is sufficient.

2.3.1.1.2 Part 91 subpart F overwater operations outside very high frequency (VHF) voice communication coverage require two long-range communication systems (LRCS), except when an aircraft has two VHF radios, in which case only one high frequency (HF) radio is sufficient.

2.3.1.2 Title 14 CFR part 121, § 121.351; part 125, § 125.203; and part 135, § 135.165 use a different term, “extended over-water” operations, defined in 14 CFR part 1, § 1.1 as more than 5 0 NM from the nearest shoreline.

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2.3.1.2.1 Section 121.351 specifically requires two “independent long-range navigation systems” for extended over-water operations.

2.3.1.2.2 Sections 125.203 and 135.165 use different language, and only require “two approved independent navigation systems suitable for navigating the airplane along the route” within the “degree of accuracy required for ATC.” This allows extended over-water operations along ATS routes that have ground-based Navigational Aid (NAVAID) coverage, without any LRNS.

2.3.1.2.3 For parts 121, 125, and 135, extended over-water operations “in certain geographic areas” with only a single LRNS can be authorized via operations specification (OpSpec) B054, which defines an area by coordinates where only one LRNS is sufficient.

2.3.1.2.4 Extended overwater operations outside VHF voice communication coverage require two LRCSs, except for holders of OpSpec B045, which defines an area by coordinates where only one LRCS is sufficient.

2.3.2 FAA regulations governing “Flight Rules” (this is the title of part 91 subpart B), on the other hand, are applicable to all operators, in U.S. sovereign airspace only.1 These so-called “flight and maneuver” regulations are generally harmonized with ICAO rules, in accordance with Article 12 to the Chicago Convention. Exceptions are listed as “Differences” in the relevant AIP. In the U.S. AIP, these are found in Section GEN 1.7, Differences From ICAO Standards, Recommended Practices and Procedures.

2.3.3 U.S. operators flying outside U.S. sovereign airspace must abide by the “flight and maneuver” regulations in effect for that airspace. If the airspace is “high seas” (“high seas” airspace generally begins outside 12 NM from the nearest shore), the applicable rules are found in ICAO Annex 2 (titled “Rules of the Air”), and ICAO Doc 7030.2 In other countries’ sovereign airspace, information on regulations is found in the relevant AIP, with Differences from ICAO SARPs also notified there.

2.3.3.1 Section 91.703 says that you must comply with ICAO Annex 2 if you operate your U.S.-registered aircraft “over the high seas.” Section 91.703 further requires that you, when within a foreign country, follow the rules “relating to the flight and maneuver of aircraft there in force.”

2.3.3.2 According to §§ 121.11, 125.23(b), and 135.3(a)(2), for operations under each respective part, when operating within a foreign country, you must comply with the air traffic rules of the country concerned and any local airport rules that may be in force. You must also follow all rules of that part that are more

1 Exception: § 91.703 imposes the following subpart B flight rules for operations of civil aircraft of U.S. registry over the high seas: §§ 91.117(c), 91.127, 91.129, and 91.131.

2 In addition, 14 CFR contains three flight and maneuver regulations (listed in footnote 1) which apply to operations of civil aircraft of U.S. registry over the high seas.

2-5 restrictive than the rules of the foreign country in which you are operating, as long as you can do so without violating the rules of that country.

Note: In some countries, Annex 6 fuel requirements are in force, which may be more restrictive than applicable 14 CFR rules.

2.3.4 Differing Airspace Requirements. It is quite possible to transit regions with significantly different procedures in one long-range flight. Therefore, you should familiarize yourself with the equipment and procedural requirements to file and fly in each segment of foreign airspace in which you intend to operate by referencing, for example, the appropriate State’s AIP.

2.4 ICAO Guidance Documents and Reference Material. Find the following ICAO documents at the ICAO store at https://store.icao.int.

2.4.1 Guidance Documents. We developed much of the material in this AC from these foundational documents: ICAO Annexes, other ICAO guidance documents, related sections of 14 CFR, and other FAA guidance material.

2.4.2 Chicago Convention. We single out the following articles of the Convention on International Civil Aviation (listed in ICAO Doc 7300) because of their importance in regulating international aviation. If you operate in oceanic and remote continental airspace, you should thoroughly understand them.

• Article 1, Sovereignty.

• Article 12, Rules of the Air.

• Article 29, Documents Carried in Aircraft.

2.4.3 ICAO Publications. T he principal purpose of ICAO publications is the “systematic and prompt dissemination in concise form of the policies and activities of the Organization…” These publications consist of Annexes, documents with “Procedures for Air Navigation Services” and “Regional Supplementary Procedures” in the name, manuals, and other similar publications. The following is a brief description of each category of publications, beginning with the most authoritative, and moving down the hierarchy.

2.4.3.1 An nexes. There are 19 Annexes (named in paragraph 2.2 above) to the Convention on International Civil Aviation (listed in ICAO Doc 7300). They state the SARPs.

2.4.3.2 Pro cedures for Air Navigation Services (PANS) and Regional Supplementary Procedures (SUPPS). ICAO publications with “Procedures for Air Navigation Services” in the title have special status, as does the publication “Regional Supplementary Procedures.”

2.4.3.2.1 ICAO Doc 4444, Procedures for Air Navigation Services—Air Traffic Management (PANS-ATM). These procedures complement the SARPs