U.S. Department of Transportation Federal Aviation Administration Advisory Circular Subject: Operational Authorization Process for Use of Data Link Communication System Date: 8/24/10 Initiated by: AFS-470 AC No: 120-70B Change:
FOREWORD This advisory circular (AC) presents various methods for operators of different data link systems to meet international standards set by the International Civil Aviation Organization (ICAO) and the regional airspace authorities. The Federal Aviation Administration (FAA) notes that there is presently no requirement in Title 14 of the Code of Federal Regulations (14 CFR) to have data link communications when operating in the National Airspace System (NAS). Instead, the regulations in 14 CFR govern radio communication systems, and nothing in this AC relieves an operator from the requirement to have and use a voice communication system when operating in international airspace or the NAS. However, operators that choose to use a data link system (in addition to the required voice communication system) must obtain FAA design approval and a revision to their 14 CFR part 121, 125, 125M, or 135 operation specifications (OpSpecs), part 91 subpart K (part 91K) management specifications (MSpec) or part 91 letter of authorization (LOA), as applicable.
ORIGINAL SIGNED BY Lawerence Fields for
John M. Allen Director, Flight Standards Service
CONTENTS P a r a g r a p h P a g e
1. Purpose1
2. Cancellation1
3. Applicability1
4. Related Material (current editions)2
5. How to Order4
6. Background and Definitions4
7. RCP Concept8
8. Authorization To Use Data Link Communications in Flight Operations10
9. Flightcrew Qualification for use of Data Link Communications12
10. Other Operational Issues19
11. Maintenance20
12. Data Link Communications Operational Use21
13. Data Link Event Reporting22
14. Foreign Air Carriers24
APPENDIX 1. SAMPLE DATA LINK EVENT REPORTING INFORMATION
(1 page)1
APPENDIX 2. DATA LINK COMMUNICATIONS MINIMUM EQUIPMENT LIST (MEL) AND MASTER MINIMUM EQUIPMENT LIST (MMEL) PROVISIONS
(2 pages)…………1
APPENDIX 3. PART 129 PROVISIONS FOR USE OF DATA LINK IN U.S. AIRSPACE
(1 page)1
APPENDIX 4. ACRONYMS AND ABBREVIATIONS (3 pages)1
APPENDIX 5. APPLICATION AND TRAINING GUIDANCE (2 pages)1
APPENDIX 6. DATA LINK SYSTEMS AND OPERATING ENVIRONMENT (4 pages)...1
Table 1. Definitions for Different Types of Data Link Systems and Operations1
Table 1A. Definitions for Sub-Networks4
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1. PURPOSE. This advisory circular (AC) presents various methods for operators of different data link systems to meet international standards set by the International Civil Aviation Organization (ICAO) and the regional airspace authorities. The Federal Aviation Administration (FAA) notes that there is presently no requirement in Title 14 of the Code of Federal Regulations (14 CFR) to have data link communications when operating in the National Airspace System (NAS). Instead, the regulations in 14 CFR govern radio communication systems, and nothing in this AC relieves an operator from the requirement to have and use a voice communication system when operating in international airspace or the NAS. However, operators that choose to operate in a reduced separation standard that requires the use of a data link system (in addition to the required voice communication system) must obtain FAA design approval and a revision to their 14 CFR part 121, 125, 125M, or 135 operation specifications (OpSpecs), part 91 subpart K (part 91K) management specifications (MSpecs) or part 91 letter of authorization (LOA), as applicable. The original AC 120-70 was applicable to Aeronautical Telecommunication Network (ATN), very high frequency (VHF) data link (VDL) Mode 2 communication systems. The Future Air Navigation System (FANS) 1/A system used in oceanic and remote airspace is an analog system which communicates over Aircraft Communications Addressing and Reporting System (ACARS). Guidance is needed for the operation of all systems and therefore the first revision AC 120-70A, was created.
2. CANCELLATION. AC 120-70A, Operational Authorization Process for use of Data Link Communication System, December 29, 2005 is cancelled.
3. APPLICABILITY. This AC applies to aircraft and operators operating under parts 91, 91K, 121, 125, 125M, 129 (for operations in the NAS) and 135. This AC describes the process for obtaining operational authorization for data link communication systems, acceptable methods for training and maintenance, and operational policies for use. In addition, it describes appropriate actions in the event of an air traffic control (ATC) data link communications event.
a. Exceptions. This AC does not address the use of data link communications for Aeronautical Operational Control (AOC) and certain specific Air Traffic Service (ATS) applications such as the following:
• Pre-departure Clearance (PDC);
• Digital Automatic Terminal Information Service (D-ATIS);
• Terminal Weather Information for Pilots (TWIP);
• Oceanic Clearance Delivery (OCD);
• Graphics/Text Weather Server (G/TWS); and
• Digital Delivery of Expected Taxi Clearance (DDTC).
NOTE: This AC is not applicable to ADS-B which is not a data link system.
It is a transponder based 1090 Mhz squitter which transmits position information for surveillance only. The communication is line of sight on frequency 1090 Mhz.
b. Compliance. The data link system should comply with the following:
• Applicable International Standards and Recommended Practices (SARPS);
• Procedures for Air Navigation Services (PANS);
• Regional Supplements (Doc 7030);
• Annex 10, Aeronautical Telecommunications, Volume II to the Convention on International Civil Aviation;
• FANS-1A FANS Operations Manual (FOM); and
• RTCA DO-306, ED-122, Safety and Performance Standards for Air Traffic Data Link Services in Oceanic and Remote Airspace.
NOTE: In addition, this AC is consistent with Volume III, Part I, Digital Communication Systems, Chapter 3, Aeronautical Telecommunication Network (ATN).
4. RELATED READING MATERIAL (current editions).
a. 14 CFR. The following 14 CFR parts are applicable to the communications systems and applications covered in this document: parts 21, 23, 25, 27, 29, 43, 91, 91K, 121, 125, 129 and
135.
b. ACs. The following ACs provides additional information that may assist in the operational authorization of data link communications systems:
(1) AC 20-140, Guidelines for Design Approval of Aircraft Data Link Communication Systems.
(2) AC 120-160, Onboard Recording of Controller-Pilot Data Link Communication in Crash Survivable Memory.
c. ICAO Documents.
(1) Document 4444 (PANS/ATM). Procedures for Air Navigation Services - Rules of the Air and Air Traffic Services.
(2) Global Operational Data Link Document (GOLD). ICAO Global Guidelines for data link operations.
(3) Annex 6. Operation of Aircraft.
(4) Annex 10. (Standards and Recommended Practices-SARPs), Volume III, Part 1, Data link Communications Systems.
(5) Annex 11. Air Traffic Services.
(6) Document 7030, Regional Supplementary Procedures.
(7) Document 9869, Manual on Required Communication Performance (RCP) First Edition -2008.
d. FANS Interoperability Team and FANS Interoperability Group Global Document.
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(1) FOM (current edition); and
(2) North Atlantic (NAT) guidance material.
e. Source Documents. The following source documents were consulted:
(1) Data Link Communication Operational Authorization Information Package (14 March 06). Summarizes the operational authorization process for Pacific operations and provides “lessons learned” by Pacific operators and ATS Providers. Published on FAA oceanic procedures Web site: http://www.faa.gov/about/office_org/headquarters_offices/ato/ service_units/enroute/oceanic/.
(2) FANS Operations Manual (FOM). The FOM has been adopted as the basic source document for data link operations throughout the Asia-Pacific Region, some of the Arab and North Africa FIRs. Part 5 of the FOM contains basic procedures for Controller-Pilot Data Link Communication (CPDLC) and part 6 has Automatic Dependent Surveillance (ADS) contract procedures.
(3) FAA Oceanic Notices to Airmen (NOTAMS) and State Aeronautical Information Publications (AIP). Specific policy and procedures related to CPDLC and ADS operations in individual FIR’s are published in International NOTAMS and in individual State AIPs.
(4) FAA Pacific/Alaska Chart Supplements and North Atlantic Doc 001. These publications currently contain policy and procedures for use of SAT Voice and will be updated as needed.
(5) North Atlantic Minimum Navigation Performance Specification (MNPS) Airspace Operations Manual. This document is published on behalf of the North Atlantic Systems Planning Group by the European and North Atlantic Office of ICAO, and includes data link material.
(6) Radio Technical Commission for Aeronautics (RTCA) Inc. Documents (RTCA/DO) and European Organization for Civil Aviation Equipment (EUROCAE) documents.
The following RTCA documents are available from RTCA Inc., 1140 Connecticut Avenue, NW.
Suite 1020, Washington, DC 20036:
(a) RTCA/DO-258A/ED-100A, Interoperability Requirements for ATS Applications Using ARINC 622 Data Communications, dated April 7, 2005.
(b) RTCA/DO-264/ED-78A, Guidelines for Approval of the Provision and Use of Air Traffic Services Supported by Data Communications, dated December 14, 2000.
(c) RTCA/DO-280B/ED-110B, Interoperability Requirements Standard for ATN Baseline1 (Interoperability Requirements Standards (INTEROP) ATN B1), dated June 26, 2007.
(d) RTCA/DO-290 Changes 1 and 2/ED-120 Changes 1 and 2, Safety and Performance Requirements Standard for Air Traffic Data link Services in Continental Airspace (Continental Software Problem Report (SPR) Standard), dated April 29, 2004.
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(e) RTCA/DO-305/ED-154, Future Air Navigation System 1/A (FANS 1/A) Aeronautical Telecommunications Network (ATN) Interoperability Standard, dated June 26, 2007.
(f) RTCA/DO-306/ED-122, Safety and Performance Standard for Air Traffic Data link Services in Oceanic and Remote Airspace (Oceanic SPR Standard), dated October 11, 2007.
(g) ED-93, Minimum Aviation System Performance Standard for CNS/ATM Message Recording Systems, dated November 23, 1998.
5. HOW TO ORDER. A copy of this AC and other ACs mentioned herein may be obtained from: U.S. Department of Transportation, Subsequent Distribution Office, SVC-121.23 Ardmore East Business Center, 3341 Q 75th Ave. Landover, MD 20785. Identify this publication when you order FAA AC 120-70B, Operational Authorization Process for Use of Data Link Communication Systems.
6. BACKGROUND AND DEFINITIONS.
a. History. The original AC, AC 120-70, was applicable to ATN VHF data link (VDL) Mode 2 communication systems. The FANS 1/A system used in oceanic and remote airspace is a data link system which communicates over Aircraft Communications Addressing and Reporting System (ACARS) which uses a variety of sub-networks, such as satellite, VDL Mode 0/A, VDL Mode 2, and HFDL.
b. Data Link Implementation. Data link applications are being implemented in flight operations utilizing FANS-1/A (which includes CPDLC and Automatic Dependent Surveillance- Contract (ADS-C). Data link applications operate without any specific knowledge by the user as to whether a satellite, VHF, (VDL M0/A or VDL M2) or HF data link (HFDL) sub-network service is in use. However, these applications may be limited by the level of end-to-end data link service implementation in use (e.g., ACARS, FANS-1/A ARINC 622). This AC provides information for U.S. operators, aircraft and data link manufacturers, various inspectors, foreign air carriers operating in U.S. airspace, and other aviation organizations regarding a means acceptable to the FAA for the use of data link systems in ATS communications. This information is intended to facilitate the operational authorization of data link systems, promote timely and comprehensive program implementation, encourage development of standard practices for the application of data link techniques, and provide an appropriate response to special data link events.
c. Definitions. Certain definitions in this AC are taken from other FAA materials. Other definitions are unique to this AC, and their application is limited to use with data link systems.
(1) Aircraft Certification Office (ACO). FAA offices responsible for the determination of aircraft airworthiness and other issues related to parts 21, 23, 25, 33, and other airworthiness rules. ACOs issue type certificates (TC), and Supplemental Type Certificates (STC), and are responsible for the technical assessment of service difficulties and Airworthiness Directives (AD).
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(2) Aircraft Evaluation Group (AEG). AEG has a variety of responsibilities, which include the following:
• Providing operational input to Federal Aviation Administration engineering offices and to the manufacturer during the aircraft design and type certification process.
• Evaluating the aircraft, its system, and the manufacturer’s recommended procedures from unique operational characteristics.
• Determining recommended minimum flight crewmember training, checking, and currency requirements.
• Establishing pilot type rating needs and requirements.
• Participating in crew complement determinations.
• Establishing special training requirements (such as dutch roll training in a B-727).
• Developing and revising master minimum equipment lists (MMEL).
• Developing maintenance program requirements and reviewing maintenance programs to determine whether there are adequate instructions for the procedures being used.
• Providing operational guidance for airworthiness directives (AD), service difficulty reports (SDR), and supplemental type certificates (STC0.
• Convening and providing a chairperson to flight standardization boards (FSB), flight operations evaluation boards (FOEB), and maintenance review boards (MRB).
• Conducting initial flight checks of Flight Standards operations inspectors, the aircraft manufacturer’s initial pilot cadre, initial operator pilots, and FAA engineering flight test pilots, if necessary, for a new type of aircraft type.
• Coordinating with the National Simulator Team on evaluation of data packages for flight simulator acceptance.
(3) Certificate-Holding District Office (CHDO). An AFS office responsible for the administration of 14 CFR part 119 certificate authority for operations conducted under parts 121, 125, or 135 for a particular certificate holder.
(4) Air Traffic Data Link Service. A data communication capability comprising air/ground and ground/ground data network services, specified data link message sets and protocols, aircraft equipment, ATS Facility equipment, and operational procedures intended to provide primary or supplemental ATS communications.
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(5) Special Data Link Event. For the purpose of this AC, a special data link event is one or more of the following occurrences or situations related to data link:
(a) In-flight traffic conflicts or potential conflicts as determined by a flightcrew member in which use of a data link service is suspected to be contributing cause.
(b) Near mid-air collisions (NMAC) in which the use of a data link service is suspected to be a contributing cause.
(c) Data link system performance below that of normal operation or required by the operational procedure (e.g., RCP 240).
(d) ATC operational error involving the use of data link associated with a data link procedure or operation.
(e) Other occurrences or situations in which use of a data link service is suspected to compromise continued operational safety. Loss of standard ATC separation resulting from a procedure or maneuver where a data link transaction, failure, or unmonitored error is suspected to be a factor.
(f) Use of the data link service that caused excessive crew workload.
(g) A data link service that provides reasonable information but is subsequently verified to be erroneous.
(h) An excursion of 500 feet or more from an assigned flight level/altitude, or a lateral/longitudinal deviation exceeding ATS minimum separation criteria in which use of a data link service is suspected to be a contributing cause.
(6) Data Link Service Academic Training. Training that exclusively addresses knowledge requirements (rather than skills), and is usually related to achieving satisfactory knowledge of data link service concepts, RCP types, systems, limitations, or procedures. The academic training on data link services is generally accomplished using a combination of classroom methods (stand up instruction, slide/tapes, computer-based instruction (CBI), tutorial, etc.), flight manual information, bulletins, or self-study.
(7) Data Link Service Use Training. This is training that addresses all of the skills related to the operational use of data link services including knowledge and skills needed to receive information provided by data link services, and appropriately accept, reject, cancel, or defer a response to that information. In addition, this training includes the knowledge and skills needed to load, store, formulate, and request information from the data link service.
(8) Data Link System. The different systems include ATN-Baseline 1, a digital system and FANS-1A, which is basically an analog based system. At the present time the digital operation is known as VDL-Mode 2 system. The analog operation is known as the VDL-Mode 0/A. The FANS 1/A system uses both digital and analog components. The data link applications are digital and binary encoded, and then processed by the ACARS convergence function (ACF) for transmission over a character-oriented network.
(9) Flight Standards District Office (FSDO). An FAA field office serving an assigned geographical area and staffed with Flight Standards (AFS) personnel who serve the aviation industry and the general public on matters relating to the licensing of aviation personnel, certification of aircraft and operational authorization of air carriers, commuter and general aviation operations.
(10) Flight Standards Board (FSB). The FSB’s primary responsibilities are to determine the requirements for pilot type ratings, to develop minimum training recommendations, and to ensure initial flight crewmember competency in accordance with AC 120-53, Crew Qualification and Pilot Type Rating Requirements for Transport Category Aircraft Operated under 14 CFR Part 121. This information is published in a report that is sent to AFS-200 for coordination. After approval, it is to be used by the principal operations inspector (POI) as guidance in approving operator training, checking, and currency programs. The report is distributed to field offices through the master minimum equipment list (MMEL) subsystem of the Aviation Safety Analysis System (ASAS) data base. Specific functions of the FSB are as follows:
(a) Determination of Pilot Type Ratings. The FSB determines the requirement for a pilot type rating for new aircraft usually during certification flight tests. The FSB also evaluates differences in follow-on aircraft to determine if a new pilot type rating is required.
(b) Development of Training Objectives. The FSB develops training objectives for normal and emergency procedures and maneuvers and reviews training device requirements.
(c) Training Recommendations. The FSB publishes recommendations for use by POIs during approval of an operator’s training program. In developing training objectives and procedures, the FSB considers unique requirements of an aircraft such as the fly-by-wire electronic flight control system and the side-stick controller of the Airbus 320.
(d) Initial Training/Checking. Board members usually conduct initial training and checking of the manufacturer’s pilots and FAA operations inspectors.
(e) Review of Existing Training Programs. When required, the FSB may review training programs for existing aircraft to evaluate the effectiveness of the training.
(f) Accidents. In case of an accident, FSB members may be consulted on training or crewmember competency issues involving aircraft assigned to the board.
(11) Follow-on STC (as related to data link communications). A data link communications STC other than as described in item (12) below for an "Initial TC/STC." The following examples are considered to be "follow-on" STCs:
(a) A previously approved data link communications installation, installed in a subsequent type or model aircraft.
(b) Changes of display configuration (flight management system (FMS)/data link display), supporting system engine indicating and crew alerting system (EICAS)/electronic Par 6 Page 7
Page 8 Par 6 centralized aircraft monitoring (ECAM) or other aircraft interface (Digital Flight Data Recorder) DFDR, etc.).
(12) Initial TC/STC (as related to data link communications). The first FAA data link communications airworthiness approval (in accordance with a TC or STC) of any one or combination of the following components: a data link processor and/or management unit, data link communications avionics.
NOTE: Previously approved data link communications systems, may require an initial TC/STC, if the part number of any of the above components changes due to a significant modification that changes the system.
(13) Maintenance Review Board (MRB). An FAA board responsible for establishing maintenance requirements for a specific aircraft type. MRB requirements are usually formulated in conjunction with information provided by the manufacturer and prospective operators through industry working groups. FAA CHDOs apply MRB requirements in reviewing and approving each carrier's proposed maintenance program.
(14) Master Minimum Equipment List (MMEL). A FAA document listing stipulations in accordance with 14 CFR §§ 121.628 and 135.179 that provides authorization for the continuation of flight beyond a terminal point with certain equipment inoperative. AEGs develop MMELs in conjunction with a Flight Operation Evaluation Board (FOEB) established for each aircraft type. The MMEL, which is associated with a particular type of aircraft, serves as the basis for MELs, which are associated with an air carrier’s operation of that aircraft type.
(15) NAS. Information on the NAS related to operations and use of air traffic data link services can be found in AIP, airmen’s information manual, NOTAM, Jeppesen Charts, or similar resources. The common network of U.S. airspace is comprised of the following:
• Air navigation facilities,
• Equipment and services,
• Airports,
• Aeronautical charts,
• Rules,
• Regulations,
• Procedures,
• Technical information,
• Manpower,
• Materials, and
• System components shared jointly with the military.
(16) National Simulator Evaluation Team (NSET). Team of FAA operations specialists responsible for evaluating flight simulators to aid principal operations inspectors (POI) in approving those simulators in accordance with regulatory requirements (e.g., NSET evaluations support POI approval of a particular simulator for use in a specific part 121 program).
(17) Principal Inspector (PI). Refers to one of three FAA PIs: principal avionics inspector (PAI), POI, or principal maintenance inspector (PMI).
(a) PAI. The FAA inspector assigned responsibility for overseeing all avionics issues relative to a specific operator, including input to training programs, OpSpecs, MEL requests, etc.
(b) POI. The FAA inspector assigned responsibility for overseeing all operational issues relative to a specific operator, including approval of training programs, OpSpecs approval, maintenance programs, MEL change requests, etc.
(c) PMI. The FAA inspector assigned responsibility for overseeing all maintenance issues relative to a specific operator, including input to training programs approved maintenance programs, OpSpecs, MEL requests, etc.
(18) Type Certificate (TC). An FAA certificate certifying that the respective aircraft, engines, or other components meet airworthiness requirements of the regulations.
(19) Supplemental Type Certificate (STC). An FAA certificate certifying that modifications to the respective aircraft, engines, or other components meet airworthiness requirements of the regulations.
7. RCP CONCEPT.
a. The RCP Concept. The concept of RCP relates to the communications component of the Communication, Navigation, and Surveillance / Air Traffic System Management (CNS/ATM) framework, and complements Required Navigation Performance (RNP) and Required Surveillance Performance (RSP). In general, the requirements for operation in a defined airspace, or performance of a defined procedure, include elements of CNS functionality and performance, as well as ATM functionality and performance. The guidance provided in this AC regarding RCP is consistent with ICAO Doc 9869, Manual on RCP. RCP is a statement of the performance requirements for operational communication in support of specific ATM functions. The RCP is determined by cognizant authorities in consideration of air traffic operations, target levels of safety, separation assurance, AFS and functional hazard analysis associated with the airspace, operation or procedure. Thus, RCP is operationally derived and not based on any specific technology, or combination of technologies, that may be utilized for communications. The performance of a communications is generally accepted as comprising communication transaction time, integrity, continuity, and availability.
b. RCP Type. An RCP type is a label (e.g., RCP 240) that represents the values assigned to RCP parameters for communication transaction time, continuity, availability and integrity.
(1) Communication transaction time. The maximum time for the completion of the operational communication transaction after which the initiator should revert to an alternative procedure.
(2) Continuity. The probability that an operational communication transaction can be completed within the communication transaction time.
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(3) Availability. The probability that an operational communication transaction can be initiated when needed.
(4) Integrity. The probability of one or more undetected errors in a completed communication transaction.
c. RCP Type Allocation. RCP type allocation is the process of apportioning the various RCP type values to the various parts of the system. The results of this process are RCP type allocations that are used to:
(1) Assess viability of different technologies to meeting operational requirements;
(2) Approve the provision of air traffic services supported by communication systems;
(3) Determine when to initiate contingency procedures;
(4) Design, implement and qualify communication services;
(5) Design, implement, qualify and approve aircraft type designs;
(6) Approve aircraft operators for RCP operations when required; and
(7) Operationally monitor, detect and resolve non-compliant performance.
d. Performance-Based Communications. Performance-based communications is based on one or more RCP type(s) and their allocations, and any other functional and performance criteria for the intended operation, for example:
(1) Specific message set or phraseology and transaction types;
(2) Interactive capability of voice communication;
(3) Air-ground integration capability of data communication;
(4) Interoperability criteria for a data link system, including its sub-networks; and
(5) Procedures for non-compliant performance and contingency.
e. RCP Specifications. An RCP specification provides the criteria for a particular RCP type, its allocations, and any other specific criteria. RCP specifications can be found in international standards and guidance material, such as RTCA DO-306/ED-122 as augmented by regional documentation.
f. Actual Communications Performance (ACP).
(1) ACP is the dynamic assessment of the actual operational performance a communication system, with human performance and technical performance included in the assessment. Human performance considers such factors as training, procedures and Human Page 10 Par 6