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4.3.2.6.4 Prior to listing NPE aircraft on the NSAL, the FAA will provide written notification of relevant ADS-B equipment issues to the owner/operator and address associated with the aircraft’s registry in an effort to coordinate NPE corrective action. In most instances, a 45-day period is allowed from the date associated with the FAA notification letter to complete NPE corrective action.
All NPE aircraft are subject to NSAL listing after the 45-day period has elapsed and corrective action has not been completed.
Note: NPE notifications mailed to unmonitored mailboxes may result in aircraft being listed to the NSAL (after 45 days) without owner/operator awareness. Owner/operators with addresses associated with an unmonitored mailbox (e.g., LLC or non-resident addresses) are advised to request a PAPR for awareness of ADS-B Out equipment performance and the NSAL status of their aircraft.
4.3.2.6.5 The operation of aircraft with certain NPE characteristics (e.g., erroneous position reports) present a significant safety hazard to surrounding airspace and ATC services. Hazardous NPE aircraft may require immediate placement on the NSAL to mitigate applicable safety risks prior to owner/operator notification.
4.3.2.6.6 In rare cases, it is necessary for the FAA to issue an Aircraft Condition Notice (FAA Form 8620-1) to prevent operation of aircraft with hazardous NPE characteristics.
4.3.2.6.7 Owner/operators receiving an NPE notification letter and/or Aircraft Condition Notice should follow the instructions provided in those documents and contact the handling aviation safety inspector (ASI) as soon as possible to coordinate required corrective action. Following NPE corrective action, a verification flight must be conducted pursuant to § 91.407(b), and the handling ASI should be notified, to validate equipment performance. When the handling ASI determines the NPE condition has been corrected, they will notify the owner/operator and, when applicable, initiate the process for removal of the aircraft from the NSAL.
Note: Once requested, removal of aircraft from the NSAL can take up to 30 days.
4.3.2.6.8 Aircraft on the NSAL are identified on the cover page of an applicable PAPR with the following language (in red font): Aircraft is on No Services List. This language is omitted from a PAPR associated with aircraft not currently on the NSAL. See paragraph 4.3.2.5.6 for information on obtaining a PAPR.
4.3.3 Operation of Aircraft with Inoperative ADS-B. Section 91.225(g) permits ATC to authorize the operation of aircraft with inoperative ADS-B or that do not have ADS-B installed into airspace where it is required. Under § 91.225(g), operators must make requests for ATC-authorized deviations from the requirements in § 91.225 to the ATC
4-7 facility that has jurisdiction over the concerned airspace or airport movement area within the time periods specified below:
1. For operation of an aircraft with inoperative ADS-B equipment 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, operators must make the request at least 1 hour before the proposed operation.
4.3.3.1 Air Carriers Procedures. Air carriers are not precluded from using the ADS-B Deviation Authorization Preflight Tool (ADAPT); however, the Air Traffic Control System Command Center (ATSCSS) will facilitate coordination with FAA facilities for flights that are equipped with ADS-B that is inoperative. Collaborative Decision Making (CDM) participants should use the Tactical Customer Advocate (TCA) webpage or call the TCA desk with the call sign, proposed departure time, requested route of flight, and requested altitude. The TCA will coordinate with all FAA facilities along the route of flight. Approval/denial will be provided with any restrictions to the route/altitude for the operation of the flight with the failed ADS-B/transponder.
4.3.3.2 All Other Operators. All other operators are encouraged to use ADAPT to document your request and authorization (see paragraph 4.3.5). You may also request coordination through the departure airport ATC tower. The tower will initiate the coordination of the request.
Note 1. Aircraft must have an operable Mode C transponder in order to use ADAPT. If the failure results in the loss of all transponder functions, you must coordinate through the ATCSCC or the local facility, as appropriate, or use your existing procedures for an inoperative transponder.
Note 2. All airborne failures will be handled by the FAA facility where the failure occurs. The FAA facility will coordinate through the ATCSCC if necessary, who will then coordinate with all FAA facilities along the remaining route of flight.
4.3.4 Operation of Aircraft Not Equipped With ADS-B. In April 2019, the FAA published a notice (84 FR 12062) to the Federal Register clarifying policy for authorizations to operators of aircraft not equipped with ADS-B (refer to Docket Number FAA-2019-0239, Statement of Policy for Authorizations to Operators of Aircraft That are Not Equipped With Automatic Dependent Surveillance-Broadcast (ADS-B) Out Equipment, at https://www.federalregister.gov/). Operators are encouraged to review the notice, summarized below.
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4.3.4.1 To operate in ADS-B airspace, an operator whose aircraft is not equipped with ADS-B Out equipment must obtain a preflight authorization in accordance with § 91.225(g). The operator has the responsibility to obtain a preflight authorization from ATC for all ADS-B Out airspace on the planned flight path. For the reasons explained in the policy, however, the FAA will be very unlikely to issue routine and regular authorizations to scheduled operators seeking to operate non-equipped aircraft in rule airspace. Likewise, although unscheduled operators may request authorizations for airspace at capacity constrained airports as defined in the policy, issuance of an authorization may prove difficult to obtain.
4.3.4.2 Note that the provision of air traffic services to a non-ADS-B-equipped aircraft whose flight transits ADS-B Out airspace will not constitute authorization under § 91.225(g). Although ATC will be able to observe that an aircraft is not equipped with ADS-B Out equipment, ATC will not be responsible for determining whether non-equipped aircraft operating in the NAS are properly authorized to operate in ADS-B Out airspace. The provision of air traffic services is separate from and will not constitute an authorization to deviate from the ADS-B Out equipage requirements while operating in that airspace. The non-equipped operator, as always, will have the responsibility to ensure compliance with the regulations, which includes obtaining a preflight authorization in accordance with § 91.225(g).
4.3.5 ADAPT. The FAA is developing a web-based mechanism for requesting authorization in accordance with the regulation and this policy. You may access ADAPT at https://sapt.faa.gov/. While ADAPT is intended primarily for requests to operate without ADS-B, you may also choose to use it as a means to request an authorization to operate with inoperative ADS-B. Operators who coordinate certain operations with an FAA TCA should continue to make requests through the TCA. Refer to the ADAPT User Guide for additional information.
4.4 Flight Plans (FP). The information to complete the ICAO FP continues to evolve with the introduction of NextGen equipment and capabilities. The information provided here represents just some of the ADS-B specific information elements. For the most current and complete instructions and descriptions of FP filing codes, refer to AIM paragraph 5-1-9 and the FAA Flight Planning Information website at http://www.faa.gov/ about/office_org/headquarters_offices/ato/service_units/enroute/flight_plan_filing.
4.4.1 ICAO FP Item 10, Equipment. When operating aircraft equipped with ADS-B you should indicate surveillance equipment in Item 10 of the ICAO FP (FAA Form 7233-4, Pre- Flight Pilot Checklist and International Flight Plan). In addition to the transponder codes (refer to AIM paragraph 5-1-9), you should include an ADS-B capability code from the following list. Note that FAA automation does not process ADS-B reports on Very High Frequency (VHF) Digital Link Mode 4, so those codes are not listed here.
4.4.2 ADS-B Capability Codes. The ADS-B capability codes are as follows:
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• B1: ADS-B with dedicated 1090 megahertz (MHz) ADS-B Out capability.
• B2: ADS-B with dedicated 1090 MHz ADS-B Out and In capability.
• U1: ADS-B Out capability using UAT.
• U2: ADS-B Out and In capability using UAT.
Note 1: Only include an ADS-B capability code when at least one serviceable ADS-B Out system is installed.
Note 2: Do not file an ADS-B code for “in” capability only. There is currently no way to indicate that an aircraft has “in” capability but no “out” capability. For aircraft with ADS-B “out” on one frequency and “in” on another, include only the ADS-B “out” code. For example, B1 or U1.
4.4.3 ICAO FP Item 18, Other Information.
4.4.3.1 SUR/260B: If you file an ADS-B capability code of B1or B2 in Item 10 and the ADS-B equipment complies with § 91.225, include the item “SUR/260B” in Item 18.
4.4.3.2 SUR/282B: If you file an ADS-B capability code of U1 or U2 in Item 10 and the ADS-B equipment complies with § 91.225, include the item “SUR/282B” in Item 18.
Note: If the ADS-B capability filed in Item 10 is not compliant with § 91.225, do not include “SUR/” information in this FP field.
4.4.3.3 CODE/: After CODE/, enter the aircraft address expressed in the form of six hexadecimal characters (e.g., “CODE/A519D9”). Operators of U.S. registered aircraft can retrieve this information from the FAA aircraft registry (https://registry.faa.gov/aircraftinquiry/NNum_Inquiry.aspx). Use the “Mode S Code (base 16 / hex)” value.
4.4.3.4 REG/: When you enter an aircraft identification in Item 7 that is different than the aircraft registration mark (e.g., “UAL123”), include REG/ symbol followed by the registration markings of the aircraft, (e.g., “N123UA”) in Item 18.
4.4.4 Anonymity Operations and VFR FPs. Section 91.227 contains specific provisions allowing operators with TSO-C154c equipment to transmit a self-assigned (randomized) temporary 24-bit address and no call sign. However, pursuant to the regulations (§ 91.227(d)(11)), the UAT anonymous 24-bit address feature may only be used when the operator “has not filed a flight plan” and “has not requested ATC services.” In 2018, the Aircraft Owners and Pilots Association (AOPA) petitioned the FAA for a limited exemption from a portion of § 91.227(d)(8) and (11). Specifically, AOPA sought an exemption to permit pilots to operate using anonymous mode when the pilot has filed a VFR FP and has not requested ATC services. Rather than granting the exemption, the
4-10 FAA clarified that it interprets the exceptions in § 91.227(d)(8) and (11) as applying to pilots who: (1) have not filed an instrument flight rules (IFR) FP; (2) have not requested ATC services, such as separation services or VFR flight following; and (3) are using a TSO-C154c self-assigned temporary 24-bit address. As a result, VFR pilots using the anonymity feature may file a VFR FP, which enables search-and-rescue capabilities, provided they do not request flight following.
Note: For any operation where ATC assigns you a discrete Mode 3/A code, you are receiving ATC services.
4.4.5 Privacy ICAO Address (PIA) Program. The FAA acknowledges the desire of some operators to limit the availability of real-time ADS-B position and identification information for a specific aircraft. To address privacy concerns and to accommodate the needs of aircraft, participation will be subject to the following conditions and limitations:
• U.S. registered.
• 1090 MHz ADS-B equipped.
• Using a third-party call sign.
• Flying in domestic U.S. airspace.
4.4.5.1 The PIA program will enable interested aircraft owners to request an alternate, temporary ICAO aircraft address, which will not be assigned to any owner in the Civil Aviation Registry (CAR). This service will be available in two phases:
1. Phase 1: No later than January 1, 2020, the application for PIA can be accessed on the FAA website at https://www.faa.gov/nextgen/equipadsb/privacy/. This service will be operated, monitored, and maintained by the FAA.
2. Phase 2: The service will be transitioned to third-party service provider(s) who will operate, monitor, and maintain this program, which will continue to be available from the above website.
4.4.5.2 To maintain the safety and integrity of air traffic operations, the FAA monitors PIA use in the NAS. The following list includes improper uses of PIAs:
• Use of PIAs assigned to another aircraft.
• Use of unassigned PIAs.
• PIAs used for operations outside of domestic airspace.
• PIAs changed in flight.
• PIAs used with an underperforming ADS-B emitter.
• PIA used with a UAT or dual 1090/UAT emitter.
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4.4.5.3 PIAs used by an aircraft other than the aircraft to which the address is assigned results is a violation of § 91.227 and notification to the FAA. Upon detection of improper PIA use, the aircraft owner/operator will be issued a warning that requires immediate action to remedy the issue before the next operation involving the assigned PIA. Failure to comply may result in the revocation of the PIA assignment. Upon revocation of the PIA assignment, the aircraft would be required to fly with its original ICAO aircraft address as found in the CAR, and failure to do so would result in regulatory enforcement action by the FAA and cessation of additional PIA assignments to that aircraft until the enforcement action is closed.
4.4.5.4 An aircraft operator may use the ICAO aircraft address originally assigned and recorded in the CAR at any time for operations, including any time while having an active PIA assignment. Use of the assigned ICAO aircraft address recorded in the CAR is required for all flights leaving U.S. sovereign airspace, and it may be used for any other flights at any time, as desired by the aircraft operator.
4.4.5.5 The FAA requires that the user submits documented validation that an ICAO code has been correctly installed into the aircraft’s ADS-B avionics after each change. Refer to the FAA PIA website for complete program details.
4.5 Preflight Requirements (U.S. Airspace).
Note: The remainder of paragraph 4.5 describes additional preflight considerations that do not apply to the operation of aircraft equipped with Satellite-Based Augmentation System (SBAS)/Aircraft-Based Augmentation System (ABAS) position sources, as further described in paragraphs 4.5.1.4 and 4.5.1.5.
4.5.1 Flight Planning Requirements for Certain Operators. Under § 91.103, pilots and operators must use all available information in planning their flight, to ensure that the performance requirements will be met for the duration of the flight. Variations in position source performance affect ADS-B Out in two specific broadcast elements required by § 91.227—Navigation Accuracy Category for Position (NACp) and Navigation Integrity Category (NIC). During certain Global Positioning System (GPS) constellation geometries, some position sources may produce values for NACp and NIC that are less than required by the rule.
4.5.1.1 Four different variants of GPS receivers are currently in use as a position source that can meet ADS-B Out rule performance requirements, to varying degrees, when adequate numbers of GPS satellites are in view. Selective availability (SA) is a feature that deliberately degraded the GPS satellite signal, resulting in a less accurate reported position. SA was deactivated in 2000.
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4.5.1.2 SA-On GPS receivers assume SA is still active (on), thereby unnecessarily inflating integrity and accuracy bounds of the positions that are no longer degraded by SA. Most GPS receivers that are only compliant with TSO-C129, Airborne Supplemental Navigation Equipment Using the Global Positioning System (GPS), are SA-On receivers.
4.5.1.3 SA-Aware GPS receivers are designed to recognize that SA is inactive and optimize the performance from GPS. GPS receivers that comply with the performance requirements of TSO-C196, Airborne Supplemental Navigation Sensors for Global Positioning System Equipment using Aircraft-Based Augmentation, are SA-Aware receivers.
4.5.1.4 SBAS receivers also use the additional signals from geostationary satellites specifically designed for aviation use, improving the quality and robustness of positioning performance. This difference in performance is most pronounced for very precise operations, such as localizer performance with vertical guidance (LPV) approaches, and for all operations when there are inoperative GPS satellites. GPS receivers complying with TSO-C145, Airborne Navigation Sensors Using the Global Positioning System Augmented by the Satellite Based Augmentation System (SBAS), or TSO-C146, Stand-Alone Airborne Navigation Equipment Using the Global Positioning System Augmented by the Satellite Based Augmentation System (SBAS), are SBAS receivers.
4.5.1.5 ABAS sensors tightly integrate GPS measurements with inertial reference/navigation sensor data, improving the quality and robustness of positioning performance. This difference in performance is most pronounced for lower lev el Required Navigation Performance (RNP) operations, such as Area Navigation (RNAV) approaches, and for all operations when there are inoperative GPS satellites.
Note 1. Some GPS receivers manufactured with a TSO-C129a appr oval are SA-Aware, and, therefore, have the sam e NACp and NIC availability as TSO-C196() approved equipment. Operators should check with their GPS receiver supplier to ver ify whether their insta lle d TSO-C129() GPS receiver is SA-On or SA-Aware.
Note 2. The wide area augmentation system (WAAS) is the desig nation of the SBAS system available in North America and is the term often used when making reference to SBAS in the United States.
4.5.2 GPS Performance Prediction. For aircraft equipped with TSO-C129() or TSO-C196() GPS units to support ADS-B Out equipment, an NACp and NIC GPS service availability prediction should be performed for the intended route of flight (route and time) using available GPS satellite information and guidance published in this AC. It is not necessary for operators of aircraft equipped with the WAAS (TSO-C145 or TSO-C146) receivers to conduct a preflight availability prediction. Operators of aircraft equipped with specific
4-13 ABAS receivers that have been reviewed by the FAA, are approved for ADS-B operations (i.e., §§ 91.225 and 91.227), and have demonstrated sufficient performance do not need to conduct a preflight availability prediction. For operations under Exemption 12555, see paragraph 4.5.3 for additional guidance. See Table 4-1, Preflight Availability Prediction, for a summary.
Note: Operators should check with their ABAS receiver supplier and/or airplane manufacturer to verify whether their installed ABAS receiver has been reviewed and approved by the FAA for operation without need to conduct a preflight availability prediction.
4.5.2.1 Prediction Methods. Operators may use any of the following preflight availability prediction methods.
4.5.2.1.1 Operators of large fleets of aircraft or users of flight planning programs may wish to use their own preflight availability verification tool. The operator is responsible for selecting a tool that accurately predicts the ADS-B position source performance for their aircraft. The tool needs to account for the GPS satellites that are in service at the time of the prediction, and may take into account unique characteristics of the GNSS receiver, aircraft integration, or installation; including performance better than required in FAA standards or use of inertial information integrated into the ADS-B Out position source. The FAA does not evaluate or approve a particular tool, but may evaluate the basis of the operator’s determination that the tool is appropriate to their aircraft, particularly if its use results in noncompliant flights in airspace where ADS-B Out is required.
4.5.2.1.2 Operators may use the FAA-provided preflight availability prediction tool, called the Service Availability Prediction Tool (SAPT) (http://sapt.faa.gov).
Refer to the SAPT User Guide for specific instructions on its use.
4.5.2.1.3 Operators may use a third-party interface, incorporating FAA GPS performance prediction data without altering performance values, to predict NACp/NIC performance outages for the aircraft’s predicted flightpath and times.
4.5.2.2 Prediction Model Parameters. The operator should use a model appropriate to their equipment, including the type of GPS receiver and the demonstrated capability to track satellites at a given mask angle. When selecting a mask angle, the operator should consider the equipment qualification, installation in the aircraft, and the effects of normal maneuvering. Aircraft are typically qualified with a five-degree mask angle, and operational experience has indicated that a two-degree mask angle can be achieved by some equipment installations. If using the SAPT, each prediction is valid for the operation within 5 minutes of the plan time and 7.5 nautical miles (NM) of the route.
The operator may wish to submit additional requests for predictions for
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4.5.2.3 Flight Planning Guidance. Predictions should be conducted within 24 hours of departure and as close to departure time as feasible, but with sufficient time to re-plan the flight in the event a segment along the planned route is predicted to have insufficient GPS service availability. The prediction should be re-evaluated prior to flight if new information (i.e., a Notice to Airmen (NOTAM)) provides notice of an unscheduled GPS satellite outage. In the event of a predicted loss of performance for any part along the intended route in the airspace where ADS-B Out is required, the flight should be re-planned so that ADS-B Out performance requirements specified in § 91.227 can be met.
Table 4-1. Preflight Availability Prediction Preflight availability prediction?
Equipment Years 2020-2024 After 2024 Exemption 12555 No Exemption SA-On Yes SAPT will determine backup surveillance and exemption authorizes flight if prediction results in NIC < 7 and/or NACp < 8.
Yes If prediction results in NIC < 7 and/or NACp < 8, operator should re-plan the flight or request ATC authorization.
Yes If prediction results in NIC < 7 and/or NACp < 8, operator should re-plan the flight or request ATC authorization.
SA-Aware No Exemption authorizes flight without the need for preflight prediction.
Yes If prediction results in NIC < 7 and/or NACp < 8, operator should re-plan the flight or request ATC authorization.
Yes If prediction results in NIC < 7 and/or NACp < 8, operator should re-plan the flight or request ATC authorization.
SBAS/ABAS No No No
4.5.3 Operations Conducted Under Exemption No. 12555. In August 2015, the Administrator issued Exemption No. 12555, a time-limited grant of exemption from § 91.227(c)(1)(i) and (iii) for the period from January 1, 2020 through December 31, 2024 to operators who made timely notification of intent to comply with the conditions and limitations.
Those operators approved to conduct operations under the conditions and limitations of Exemption No. 12555, or a similar exemption as determined by the FAA, should adhere to the additional guidance provided in this section.
4-15 Note: Operators approved to operate under Exemption No. 12555 are encouraged to review the conditions and limitations detailed in the Grant of Exemption No. 12555 at Docket Number FAA-2015-0971, Petition for Exemption, at https://www.regulations.gov/.
4.5.3.1 Under the conditions of Exemption No. 12555, operators with receivers meeting the performance requirements of TSO-C196() may operate in designated airspace for which ADS-B Out is required when the aircraft’s NACp and NIC do not meet the performance specified in § 91.227. For these operations, the operator does not need to conduct any preflight availability prediction.
4.5.3.2 Operators conducting operations under Exemption No. 12555 using TSO-C129-approved GPS receivers that do not meet the performance requirements of TSO-C196, TSO-C145, or TSO-C146 may operate in airspace where ADS-B Out is required when the aircraft’s NACp and NIC do not meet the performance specified in § 91.227, when the FAA determines that backup surveillance is available. SAPT will indicate if the FAA has determined that backup surveillance is predicted to be available during a predicted performance outage. Since the FAA must make the determination that backup surveillance is predicted to be available, the SAPT is the only tool that can provide this capability. The applicable SAPT run should be completed no more than 3 hours before the planned departure time. If ATC in the departure jurisdiction requires FP submission earlier than 3 hours prior, the SAPT for backup surveillance should be run just prior to FP submission.
Under Exemption No. 12555, operators may elect to use their own tool for preflight prediction and use SAPT only to determine the availability of backup surveillance when needed under Exemption No. 12555.
4.5.4 Preflight Prediction Compliance. Operators need to perform an ADS-B Out preflight prediction only for the intended route of flight to the intended destination. For example, when departure and/or arrival alternate airports are required, no preflight prediction is necessary for these routes. However, if you become aware of a change that could result in degraded ADS-B Out performance, such as a satellite outage prior to receiving an ATC clearance for the intended route of flight, then you should conduct a subsequent preflight prediction for the planned flight. This will ensure that ADS-B Out performance is still predicted to comply with the performance requirements of § 91.227(c)(1)(i) and (iii).
Once the pilot has received an ATC route clearance, there is no requirement to conduct a subsequent preflight prediction. Therefore, upon receiving a satisfactory preflight availability prediction and an ATC clearance for an intended route of flight, the operator will be deemed to have complied with the preflight availability prediction requirement and the performance requirements of § 91.227(c)(1)(i) and (iii). The FAA accepts that unanticipated changes in route of flight and environmental conditions may adversely affect ADS-B Out performance. ATC will continue to exercise its responsibility for the safe and efficient movement of air traffic, including the routing of traffic to meet those objectives. ADS-B preflight planning should include:
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• Identification of flights or aircraft that require completion of a preflight prediction.
• Identify the preflight prediction system (or systems) to be used.
• Include a means to document completion of a satisfactory prediction for each flight where a prediction is required.
• Retain documentation of prediction completion for a suitable period of time, such as three months.
4.5.5 GPS Interference with ADS-B Compliance. There may be times when the GPS position source cannot meet the required technical performance for compliance with § 91.227 due to planned GPS interference. In the event of a scheduled interference outage of GPS, the FAA will issue a NOTAM that identifies the airspace and time periods that may be affected by the interference. The FAA has determined that it would be impractical and not in the public interest to require operators to avoid the affected area based on the chance that an otherwise compliant flight could experience GPS interference.
Accordingly, operators should proceed with their intended operation if the only impediment to their operation is possible planned GPS interference. An operator who is required to perform a preflight availability prediction for the intended route of flight is still required to obtain a satisfactory preflight availability prediction. When a NOTAM identifies the airspace and time periods that may be affected by GPS interference, an operator will not be required to alter his or her route of flight to avoid the area based solely on that NOTAM. If an operator encounters actual GPS interference during their flight that results in a degradation of ADS-B Out performance, provided the operator has taken the appropriate preflight actions, the FAA will not consider these events to constitute a violation, as such application of the regulation would impose standard of conduct wholly outside the operator’s control.
4.5.6 SAPT Outages. The FAA will issue a NOTAM in the event of a SAPT outage. Operators who use SAPT as their preflight prediction tool will not need to conduct a preflight prediction for the duration of the outage. Additionally, any flight plans submitted to ATC with a proposed departure time within 90 minutes of SAPT return to service do not require a subsequent preflight analysis. When there is a SAPT outage and an operation falls below the performance requirements, provided the operator has taken the appropriate preflight actions with regard to relying upon SAPT, the FAA will not consider these events to constitute a violation, as such application of the regulation would impose standard of conduct wholly outside the operator’s control. For operators who have been notified by the FAA of consistent and repeated ADS-B Out performance issues, the FAA cautions that operating during a SAPT outage without first redressing the identified non-performance issue will be considered a continuation of existing noncompliance of the performance requirements.
4.6 Flightcrew Entry of Required ADS-B Data. The operator should develop operational procedures to address flightcrew entry of the ADS-B message elements required in § 91.227 and as described in paragraphs 4.6.1 through 4.6.4. If the ADS-B avionics system design does not allow for a single point of entry for this information, the AFM, AFMS, RFM, RFMS, POH, or other required flight manual must address the requirement
4-17 to enter the information multiple times through the appropriate system’s interface and to ensure that conflicting ACID information is not transmitted to ATC.
4.6.1 Mode A Code.
4.6.1.1 ATC automation relies on the Mode A code to identify aircraft under radar surveillance and to correlate the displayed target to an FP. The Mode A code is one element of the transmitted ADS-B message set. Since SSR and ADS-B surveillance will overlap in much of the NAS, correlation of the Mode A code between the transponder and the ADS-B message is necessary to ensure that a single target is resolved and correlated to an FP route.
4.6.1.2 It is imperative that the ATC-assigned transponder code is identical to the one in the ADS-B Out message. A preferable design configuration is one that provides the pilot a single point of entry for the Mode A code in both the transponder and the ADS-B Out avionics. If there is no single point of entry provided for the Mode A code into the transponder, then the AFM or operating handbook must address the requirement to enter the Mode A code into both systems separately.
Note: Transmission of conflicting transponder and ADS-B Mode A codes will result in erroneous traffic conflict alerts within the ATC automation system.
4.6.2 Aircraft’s Flight Identification (FLT ID).
4.6.2.1 An aircraft’s FLT ID is transmitted by the ADS-B Out avionics. The FLT ID is composed of a maximum of seven alphanumeric characters and, per § 91.227(d)(8), must be identical to the “Aircraft Identification” as entered in Item 7 of the FP. It is also referred to as a call sign. The FLT ID is typically entered by the flightcrew during preflight through either a flight management system (FMS) interface (control display unit (CDU)) or transponder control panel. The FLT ID for General Aviation (GA) aircraft is typically associated with the aircraft’s registration number. The aircraft owner can preset the FLT ID to the aircraft’s registration number (e.g., N235RA), since it is a fixed value, or the pilot can enter it into the ADS-B Out system prior to flight, provided the ADS-B avionics has this capability. It is important to know that the FLT ID should be input into the ADS-B system exactly as filed in block 2 or Item 7 of the FP. No additional characters should be used to fill all available fields.
4.6.2.2 Some ATC systems use transmitted FLT IDs to uniquely identify each aircraft within a given airspace and correlate them with a filed FP for the provision of surveillance and separation services. If the FLT ID is not entered correctly, ATC automation systems may not associate surveillance tracks for the aircraft to its filed FP. Therefore, air traffic services may be delayed or unavailable until this is corrected. Consequently, it is imperative that flightcrews and GA