ENR 1.16 Performance-Based Navigation (PBN) and Area Navigation (RNAV)

1.. General

1. Introduction to PBN. As air travel has evolved, methods of navigation have improved to give operators ­more flexibility. PBN exists under the umbrella of area navigation (RNAV). The term RNAV in this context, as ­in procedure titles, just means “area navigation,” regardless of the equipment capability of the aircraft. (See ­FIG ENR 1.16-1.) Many operators have upgraded their systems to obtain the benefits of PBN. Within PBN there ­are two main categories of navigation methods or specifications: area navigation (RNAV) and required ­navigation performance (RNP). In this context, the term RNAV x means a specific navigation specification with ­a specified lateral accuracy value. For an aircraft to meet the requirements of PBN, a specified RNAV or RNP ­accuracy must be met 95 percent of the flight time. RNP is a PBN system that includes onboard performance ­monitoring and alerting capability (for example, Receiver Autonomous Integrity Monitoring (RAIM)). PBN ­also introduces the concept of navigation specifications (NavSpecs) which are a set of aircraft and aircrew ­requirements needed to support a navigation application within a defined airspace concept. For both RNP and ­RNAV NavSpecs, the numerical designation refers to the lateral navigation accuracy in nautical miles which is ­expected to be achieved at least 95 percent of the flight time by the population of aircraft operating within the ­airspace, route, or procedure. This information is detailed in International Civil Aviation Organization's (ICAO) ­Doc 9613, Performance-based Navigation (PBN) Manual and the latest FAA AC 90-105, Approval Guidance ­for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System and in Remote ­and Oceanic Airspace.

   

2. Area Navigation (RNAV)
   1. General. RNAV is a method of navigation that permits aircraft operation on any desired flight path within ­the coverage of ground- or space-based navigation aids or within the limits of the capability of self-contained ­aids, or a combination of these. In the future, there will be an increased dependence on the use of RNAV in lieu ­of routes defined by ground-based navigation aids. RNAV routes and terminal procedures, including departure ­procedures (DPs) and standard terminal arrivals (STAR), are designed with RNAV systems in mind. There are ­several potential advantages of RNAV routes and procedures:
      1. Time and fuel savings;
      2. Reduced dependence on radar vectoring, altitude, and speed assignments allowing a reduction in ­required ATC radio transmissions; and
      3. More efficient use of airspace.

         In addition to information found in this manual, guidance for domestic RNAV DPs, STARs, and routes may also ­be found in Advisory Circular 90-100, U.S. Terminal and En Route Area Navigation (RNAV) Operations.

   2. RNAV Operations. RNAV procedures, such as DPs and STARs, demand strict pilot awareness and ­maintenance of the procedure centerline. Pilots should possess a working knowledge of their aircraft navigation ­system to ensure RNAV procedures are flown in an appropriate manner. In addition, pilots should have an ­understanding of the various waypoint and leg types used in RNAV procedures; these are discussed in more detail ­below.
      1. Waypoints. A waypoint is a predetermined geographical position that is defined in terms of ­latitude/longitude coordinates. Waypoints may be a simple named point in space or associated with existing ­navaids, intersections, or fixes. A waypoint is most often used to indicate a change in direction, speed, or altitude ­along the desired path. RNAV procedures make use of both fly-over and fly-by waypoints.
         1. Fly-by waypoints. Fly-by waypoints are used when an aircraft should begin a turn to the next course prior ­to reaching the waypoint separating the two route segments. This is known as turn anticipation.
         2. Fly-over waypoints. Fly-over waypoints are used when the aircraft must fly over the point prior to ­starting a turn.

            

      2. RNAV Leg Types. A leg type describes the desired path proceeding, following, or between waypoints ­on an RNAV procedure. Leg types are identified by a two-letter code that describes the path (e.g., heading, ­course, track, etc.) and the termination point (e.g., the path terminates at an altitude, distance, fix, etc.). Leg types ­used for procedure design are included in the aircraft navigation database, but not normally provided on the ­procedure chart. The narrative depiction of the RNAV chart describes how a procedure is flown. The “path and ­terminator concept” defines that every leg of a procedure has a termination point and some kind of path into that ­termination point. Some of the available leg types are described below.
         1. Track to Fix. A Track to Fix (TF) leg is intercepted and acquired as the flight track to the following ­waypoint. Track to a Fix legs are sometimes called point-to-point legs for this reason. Narrative: “direct ­ALPHA, then on course to BRAVO WP.” See FIG ENR 1.16-3.
         2. Direct to Fix. A Direct to Fix (DF) leg is a path described by an aircraft's track from an initial area direct ­to the next waypoint. Narrative:“turn right direct BRAVO WP.” See FIG ENR 1.16-4.

            

            

         3. Course to Fix. A Course to Fix (CF) leg is a path that terminates at a fix with a specified course at that fix. ­Narrative:“on course 150 to ALPHA WP.” See FIG ENR 1.16-5.

            

         4. Radius to Fix. A Radius to Fix (RF) leg is defined as a constant radius circular path around a defined turn ­center that terminates at a fix. See FIG ENR 1.16-6.

            

         5. Heading. A Heading leg may be defined as, but not limited to, a Heading to Altitude (VA), Heading to ­DME range (VD), and Heading to Manual Termination, i.e., Vector (VM). Narrative: “climb heading 350 to ­1500”, “heading 265, at 9 DME west of PXR VORTAC, right turn heading 360”, “fly heading 090, expect radar ­vectors to DRYHT INT.”
      3. Navigation Issues. Pilots should be aware of their navigation system inputs, alerts, and annunciations ­in order to make better-informed decisions. In addition, the availability and suitability of particular ­sensors/systems should be considered.
         1. GPS/WAAS. Operators using TSO-C129(), TSO-C196(), TSO-C145() or TSO-C146() systems should ­ensure departure and arrival airports are entered to ensure proper RAIM availability and CDI sensitivity.
         2. DME/DME. Operators should be aware that DME/DME position updating is dependent on navigation ­system logic and DME facility proximity, availability, geometry, and signal masking.
         3. VOR/DME. Unique VOR characteristics may result in less accurate values from VOR/DME position ­updating than from GPS or DME/DME position updating.
         4. Inertial Navigation. Inertial reference units and inertial navigation systems are often coupled with other ­types of navigation inputs, e.g., DME/DME or GPS, to improve overall navigation system performance.
      4. Flight Management System (FMS). An FMS is an integrated suite of sensors, receivers, and ­computers, coupled with a navigation database. These systems generally provide performance and RNAV ­guidance to displays and automatic flight control systems.
      5. Inputs can be accepted from multiple sources such as GPS, DME, VOR, LOC and IRU. These inputs ­may be applied to a navigation solution one at a time or in combination. Some FMSs provide for the detection ­and isolation of faulty navigation information.
      6. When appropriate navigation signals are available, FMSs will normally rely on GPS and/or DME/DME ­(that is, the use of distance information from two or more DME stations) for position updates. Other inputs may ­also be incorporated based on FMS system architecture and navigation source geometry.
      7. RNAV Navigation Specifications (Nav Specs)

         NavSpecs are a set of aircraft and aircrew requirements needed to support a navigation application within a ­defined airspace concept. For both RNP and RNAV designations, the numerical designation refers to the lateral ­navigation accuracy in nautical miles which is expected to be achieved at least 95 percent of the flight time by ­the population of aircraft operating within the airspace, route, or procedure. (See FIG ENR 1.16-1.)

         1. RNAV 1. Typically RNAV 1 is used for DPs and STARs and appears on the charts. Aircraft must maintain ­a total system error of not more than 1 NM for 95 percent of the total flight time.
         2. RNAV 2. Typically RNAV 2 is used for en route operations unless otherwise specified. T‐routes and ­Q‐routes are examples of this Nav Spec. Aircraft must maintain a total system error of not more than 2 NM for ­95 percent of the total flight time.
         3. RNAV 10.Typically RNAV 10 is used in oceanic operations. See paragraph ENR 7.4 for specifics and ­explanation of the relationship between RNP 10 and RNAV 10 terminology.

2.. Required Navigation Performance (RNP)

1. General. While both RNAV navigation specifications (NavSpecs) and RNP NavSpecs contain specific ­performance requirements, RNP is RNAV with the added requirement for onboard performance monitoring and ­alerting (OBPMA). RNP is also a statement of navigation performance necessary for operation within a defined ­airspace. A critical component of RNP is the ability of the aircraft navigation system to monitor its achieved ­navigation performance, and to identify for the pilot whether the operational requirement is, or is not, being met ­during an operation. OBPMA capability therefore allows a lessened reliance on air traffic control intervention ­and/or procedural separation to achieve the overall safety of the operation. RNP capability of the aircraft is a ­major component in determining the separation criteria to ensure that the overall containment of the operation ­is met. The RNP capability of an aircraft will vary depending upon the aircraft equipment and the navigation ­infrastructure. For example, an aircraft may be eligible for RNP 1, but may not be capable of RNP 1 operations ­due to limited NAVAID coverage or avionics failure. The Aircraft Flight Manual (AFM) or avionics documents ­for your aircraft should specifically state the aircraft's RNP eligibilities. Contact the manufacturer of the avionics ­or the aircraft if this information is missing or incomplete. NavSpecs should be considered different from one ­another, not “better” or “worse” based on the described lateral navigation accuracy. It is this concept that requires ­each NavSpec eligbility to be listed separately in the avionics documents or AFM. For example, RNP 1 is ­different from RNAV 1, and an RNP 1 eligibility does NOT mean automatic RNP 2 or RNAV 1 eligibility. As ­a safeguard, the FAA requires that aircraft navigation databases hold only those procedures that the aircraft ­maintains eligibility for. If you look for a specific instrument procedure in your aircraft's navigation database ­and cannot find it, it's likely that procedure contains PBN elements your aircraft is ineligible for or cannot ­compute and fly. Further, optional capabilities such as Radius-to-fix (RF) turns or scalability should be ­described in the AFM or avionics documents. Use the capabilities of your avionics suite to verify the appropriate ­waypoint and track data after loading the procedure from your database.
2. PBN Operations
   1. Lateral Accuracy Values. Lateral Accuracy values are applicable to a selected airspace, route, or ­procedure. The lateral accuracy value is a value typically expressed as a distance in nautical miles from the ­intended centerline of a procedure, route, or path. RNP applications also account for potential errors at some ­multiple of lateral accuracy value (for example, twice the RNP lateral accuracy values).
      1. RNP NavSpecs. U.S. standard NavSpecs supporting typical RNP airspace uses are as specified below. ­Other NavSpecs may include different lateral accuracy values as identified by ICAO or other states. (See ­FIG ENR 1.16-1.)
         1. RNP Approach(RNP APCH). In the U.S., RNP APCH procedures are titled RNAV(GPS) and offer ­several lines of minima to accommodate varying levels of aircraft equipage: either lateral navigation (LNAV), ­LNAV/vertical navigation (LNAV/VNAV), Localizer Performance with Vertical Guidance (LPV), and Localizer ­Performance (LP). GPS with or without Space-Based Augmentation System (SBAS) (for example, WAAS) can ­provide the lateral information to support LNAV minima. LNAV/VNAV incorporates LNAV lateral with vertical ­path guidance for systems and operators capable of either barometric or SBAS vertical. Pilots are required to use ­SBAS to fly to the LPV or LP minima. RF turn capability is optional in RNP APCH eligibility. This means that ­your aircraft may be eligible for RNP APCH operations, but you may not fly an RF turn unless RF turns are also ­specifically listed as a feature of your avionics suite. GBAS Landing System (GLS) procedures are also ­constructed using RNP APCH NavSpecs and provide precision approach capability. RNP APCH has a lateral ­accuracy value of 1 in the terminal and missed approach segments and essentially scales to RNP 0.3 (or 40 meters ­with SBAS) in the final approach. (See AIP ENR 1.5 Paragraph 9. RNP AR Instrument Approach ­Procedures.)
         2. RNP Authorization Required Approach (RNP AR APCH). In the U.S., RNP AR APCH procedures are ­titled RNAV (RNP). These approaches have stringent equipage and pilot training standards and require special ­FAA authorization to fly. Scalability and RF turn capabilities are mandatory in RNP AR APCH eligibility. RNP ­AR APCH vertical navigation performance is based upon barometric VNAV or SBAS. RNP AR is intended to ­provide specific benefits at specific locations. It is not intended for every operator or aircraft. RNP AR capability ­requires specific aircraft performance, design, operational processes, training, and specific procedure design ­criteria to achieve the required target level of safety. RNP AR APCH has lateral accuracy values that can range ­below 1 in the terminal and missed approach segments and essentially scale to RNP 0.3 or lower in the final ­approach. Before conducting these procedures, operators should refer to the latest AC 90-101, Approval ­Guidance for RNP Procedures with AR. (See AIP ENR 1.5 Paragraph 9.)
         3. RNP Authorization Required Departure (RNP AR DP). Similar to RNP AR approaches, RNP AR ­departure procedures have stringent equipage and pilot training standards and require special FAA authorization ­to fly. Scalability and RF turn capabilities is mandatory in RNP AR DP eligibility. RNP AR DP is intended to ­provide specific benefits at specific locations. It is not intended for every operator or aircraft. RNP AR DP ­capability requires specific aircraft performance, design, operational processes, training, and specific procedure ­design criteria to achieve the required target level of safety. RNP AR DP has lateral accuracy values that can scale ­to no lower than RNP 0.3 in the initial departure flight path. Before conducting these procedures, operators ­should refer to the latest AC 90-101, Approval Guidance for RNP Procedures with AR. (See AIP ENR 1.5 ­Paragraph 9.)
         4. Advanced RNP (A-RNP). Advanced RNP is a NavSpec with a minimum set of mandatory functions ­enabled in the aircraft's avionics suite. In the U.S., these minimum functions include capability to calculate and ­perform RF turns, scalable RNP, and parallel offset flight path generation. Higher continuity (such as dual ­systems) may be required for certain oceanic and remote continental airspace. Other “advanced” options for use ­in the en route environment (such as fixed radius transitions and Time of Arrival Control) are optional in the U.S. ­Typically, an aircraft eligible for A-RNP will also be eligible for operations comprising: RNP APCH, ­RNP/RNAV 1, RNP/RNAV 2, RNP 4, and RNP/RNAV 10. A-RNP allows for scalable RNP lateral navigation ­values (either 1.0 or 0.3) in the terminal environment. Use of these reduced lateral accuracies will normally ­require use of the aircraft's autopilot and/or flight director. See the latest AC 90-105 for more information on ­A-RNP, including NavSpec bundling options, eligibility determinations, and operations approvals.
         5. RNP 1. RNP 1 requires a lateral accuracy value of 1 for arrival and departure in the terminal area, and the ­initial and intermediate approach phase when used on conventional procedures with PBN segments (for example, ­an ILS with a PBN feeder, IAF, or missed approach). RF turn capability is optional in RNP 1 eligibility. This ­means that your aircraft may be eligible for RNP 1 operations, but you may not fly an RF turn unless RF turns ­are also specifically listed as a feature of your avionics suite.
         6. RNP 2. RNP 2 will apply to both domestic and oceanic/remote operations with a lateral accuracy value of ­2.
         7. RNP 4. RNP 4 will apply to oceanic and remote operations only with a lateral accuracy value of 4. RNP ­4 eligibility will automatically confer RNP 10 eligibility.
         8. RNP 10. The RNP 10 NavSpec applies to certain oceanic and remote operations with a lateral accuracy ­of 10. In such airspace, the RNAV 10 NavSpec will be applied, so any aircraft eligible for RNP 10 will be deemed ­eligible for RNAV 10 operations. Further, any aircraft eligible for RNP 4 operations is automatically qualified ­for RNP 10/ RNAV 10 operations. (See also the latest AC 91-70, Oceanic and Remote Continental Airspace ­Operations, for more information on oceanic RNP/RNAV operations.)
         9. RNP 0.3. The RNP 0.3 NavSpec requires a lateral accuracy value of 0.3 for all authorized phases of flight. ­RNP 0.3 is not authorized for oceanic, remote, or the final approach segment. Use of RNP 0.3 by slow-flying ­fixed-wing aircraft is under consideration, but the RNP 0.3 NavSpec initially will apply only to rotorcraft ­operations. RF turn capability is optional in RNP 0.3 eligibility. This means that your aircraft may be eligible ­for RNP 0.3 operations, but you may not fly an RF turn unless RF turns are also specifically listed as a feature ­of your avionics suite.
      2. Application of Standard Lateral Accuracy Values. U.S. standard lateral accuracy values typically ­used for various routes and procedures supporting RNAV operations may be based on use of a specific ­navigational system or sensor such as GPS, or on multi-sensor RNAV systems having suitable performance.
      3. Depiction of PBN Requirements. In the U.S., PBN requirements like Lateral Accuracy Values or ­NavSpecs applicable to a procedure will be depicted on affected charts and procedures. In the U.S., a specific ­procedure's Performance-Based Navigation (PBN) requirements will be prominently displayed in separate, ­standardized notes boxes. For procedures with PBN elements, the “PBN box” will contain the procedure's ­NavSpec(s); and, if required: specific sensors or infrastructure needed for the navigation solution, any additional ­or advanced functional requirements, the minimum RNP value, and any amplifying remarks. Items listed in this ­PBN box are REQUIRED to fly the procedure's PBN elements. For example, an ILS with an RNAV missed ­approach would require a specific capability to fly the missed approach portion of the procedure. That required ­capability will be listed in the PBN box. The separate Equipment Requirements box will list ground-based ­equipment and/or airport specific requirements. On procedures with both PBN elements and ground-based ­equipment requirements, the PBN requirements box will be listed first.(See FIG ENR 1.5-17.)
3. Other RNP Applications Outside the U.S. The FAA and ICAO member states have led initiatives in ­implementing the RNP concept to oceanic operations. For example, RNP-10 routes have been established in the ­northern Pacific (NOPAC) which has increased capacity and efficiency by reducing the distance between tracks ­to 50 NM. (See AIP Section ENR 7.4.)
4. Aircraft and Airborne Equipment Eligibility for RNP Operations. Aircraft eligible for RNP operations ­will have an appropriate entry including special conditions and limitations in its AFM, avionics manual, or a ­supplement. Operators of aircraft not having specific RNP eligibility statements in the AFM or avionics ­documents may be issued operational approval including special conditions and limitations for specific RNP ­eligibilities.

   TBL ENR 1.16-1U.S. Standard RNP Levels

   RNP Level	Typical Application	Primary Route ­Width (NM) - Centerline to Boundary
   0.1 to 1.0	RNP AR Approach Segments	0.1 to 1.0
   0.3 to 1.0	RNP Approach Segments	0.3 to 1.0
   1	Terminal and En Route	1.0
   2	En Route	2.0
   4	Oceanic/remote areas where performance-based horizontal ­separation is applied.	4.0
   10	Oceanic/remote areas where performance-based horizontal ­separation is applied.	10.0

3.. Use of Suitable Area Navigation (RNAV) Systems on Conventional Procedures and ­Routes

1. Discussion. This paragraph sets forth policy, while providing operational and airworthiness guidance ­regarding the suitability and use of RNAV systems when operating on, or transitioning to, conventional, ­non-RNAV routes and procedures within the U.S. National Airspace System (NAS):
   1. Use of a suitable RNAV system as a Substitute Means of Navigation when a Very-High Frequency (VHF) ­Omni-directional Range (VOR), Distance Measuring Equipment (DME), Tactical Air Navigation (TACAN), ­VOR/TACAN (VORTAC), VOR/DME, Non-directional Beacon (NDB), or compass locator facility including ­locator outer marker and locator middle marker is out-of-service (that is, the navigation aid (NAVAID) ­information is not available); an aircraft is not equipped with an Automatic Direction Finder (ADF) or DME; ­or the installed ADF or DME on an aircraft is not operational. For example, if equipped with a suitable RNAV ­system, a pilot may hold over an out-of-service NDB.
   2. Use of a suitable RNAV system as an Alternate Means of Navigation when a VOR, DME, VORTAC, ­VOR/DME, TACAN, NDB, or compass locator facility including locator outer marker and locator middle ­marker is operational and the respective aircraft is equipped with operational navigation equipment that is ­compatible with conventional navaids. For example, if equipped with a suitable RNAV system, a pilot may fly ­a procedure or route based on operational VOR using that RNAV system without monitoring the VOR.
2. Types of RNAV Systems that Qualify as a Suitable RNAV System. When installed in accordance with ­appropriate airworthiness installation requirements and operated in accordance with applicable operational ­guidance (e.g., aircraft flight manual and Advisory Circular material), the following systems qualify as a suitable ­RNAV system:
   1. An RNAV system with TSO-C129/ -C145/-C146 equipment, installed in accordance with AC 20-138, ­Airworthiness Approval of Global Positioning System (GPS) Navigation Equipment for Use as a VFR and IFR ­Supplemental Navigation System, and authorized for instrument flight rules (IFR) en route and terminal ­operations (including those systems previously qualified for “GPS in lieu of ADF or DME” operations), or
   2. An RNAV system with DME/DME/IRU inputs that is compliant with the equipment provisions of AC ­90-100A, U.S. Terminal and En Route Area Navigation (RNAV) Operations, for RNAV routes. A table of ­compliant equipment is available at the following website:
      https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afx/afs/afs400/afs410/media/­AC90-100compliance.pdf
3. Uses of Suitable RNAV Systems. Subject to the operating requirements, operators may use a suitable ­RNAV system in the following ways:
   1. Determine aircraft position relative to, or distance from a VOR (see NOTE 6 below), TACAN, NDB, ­compass locator, DME fix; or a named fix defined by a VOR radial, TACAN course, NDB bearing, or compass ­locator bearing intersecting a VOR or localizer course.
   2. Navigate to or from a VOR, TACAN, NDB, or compass locator.
   3. Hold over a VOR, TACAN, NDB, compass locator, or DME fix.
   4. Fly an arc based upon DME.
4. Alternate Airport Considerations. For the purposes of flight planning, any required alternate airport must ­have an available instrument approach procedure that does not require the use of GPS. This restriction includes ­conducting a conventional approach at the alternate airport using a substitute means of navigation that is based ­upon the use of GPS. For example, these restrictions would apply when planning to use GPS equipment as a ­substitute means of navigation for an out-of-service VOR that supports an ILS missed approach procedure at ­an alternate airport. In this case, some other approach not reliant upon the use of GPS must be available. This ­restriction does not apply to RNAV systems using TSO-C145/-C146 WAAS equipment. For further WAAS ­guidance see ENR 4.1 paragraph 17.
   1. For flight planning purposes, TSO‐C129() and TSO‐C196() equipped users (GPS users) whose navigation ­systems have fault detection and exclusion (FDE) capability, who perform a preflight RAIM prediction at the ­airport where the RNAV (GPS) approach will be flown, and have proper knowledge and any required training ­and/or approval to conduct a GPS‐based IAP, may file based on a GPS‐based IAP at either the destination or the ­alternate airport, but not at both locations. At the alternate airport, pilots may plan for applicable alternate airport ­weather minimums using:
      1. Lateral navigation (LNAV) or circling minimum descent altitude (MDA);
      2. LNAV/vertical navigation (LNAV/VNAV) DA, if equipped with and using approved barometric vertical ­navigation (baro‐VNAV) equipment;
      3. RNP 0.3 DA on an RNAV (RNP) IAP, if they are specifically authorized users using approved ­baro‐VNAV equipment and the pilot has verified required navigation performance (RNP) availability through ­an approved prediction program.
   2. If the above conditions cannot be met, any required alternate airport must have an approved instrument ­approach procedure other than GPS that is anticipated to be operational and available at the estimated time of ­arrival, and which the aircraft is equipped to fly.
   3. This restriction does not apply to TSO‐C145() and TSO‐C146() equipped users (WAAS users). For further ­WAAS guidance see ENR 4.1 paragraph 17.
5. General Operational Requirements
   1. Pilots must comply with the guidelines contained in their AFM, AFM supplement, operating manual, or ­pilot's guide when operating their aircraft navigation system.
   2. Pilots may not use their RNAV system as a substitute or alternate means of navigation guidance if their ­aircraft has an AFM or AFM supplement with a limitation to monitor the underlying navigation aids for the ­associated operation.
   3. Pilots of aircraft with an AFM limitation that requires the aircraft to have other equipment appropriate to ­the route to be flown may only use their RNAV equipment as a substitute means of navigation in the contiguous ­U.S. In addition, pilots of these aircraft may not use their RNAV equipment as a substitute for inoperable or ­not-installed equipment.
   4. Pilots must ensure their onboard navigation data is current, appropriate for the region of intended ­operation, and includes the navigation aids, waypoints, and relevant coded terminal airspace procedures for the ­departure, arrival, and alternate airfields.
   5. Pilots must extract procedures, waypoints, navaids, or fixes by name from the onboard navigation database ­and comply with the charted procedure or route.
   6. For the purposes described in this paragraph, pilots may not manually enter published procedure or route ­waypoints via latitude/longitude, place/bearing, or place/bearing/distance into the aircraft system.
6. Operational Requirements for Departure and Arrival Procedures
   1. Pilots of aircraft with standalone GPS receivers must ensure that CDI scaling (full-scale deflection) is ­either ¦1.0 NM or 0.3 NM.
   2. In order to use a substitute means of navigation guidance on departure procedures, pilots of aircraft with ­RNAV systems using DME/DME/IRU, without GPS input, must ensure their aircraft navigation system position ­is confirmed, within 1,000 feet, at the start point of take-off roll. The use of an automatic or manual runway ­update is an acceptable means of compliance with this requirement. A navigation map may also be used to ­confirm aircraft position, if pilot procedures and display resolution allow for compliance with the 1,000-foot ­tolerance requirement.
7. Operational Requirements for Instrument Approach Procedures
   1. When the use of RNAV equipment using GPS input is planned as a substitute means of navigation guidance ­for part of an instrument approach procedure at a destination airport, any required alternate airport must have ­an available instrument approach procedure that does not require the use of GPS. This restriction includes ­conducting a conventional approach at the alternate airport using a substitute means of navigation guidance based ­upon the use of GPS. This restriction does not apply to RNAV systems using WAAS as an input.
   2. Pilots of aircraft with standalone GPS receivers must ensure that CDI sensitivity is ¦1 NM.
8. Operational Requirements for Specific Inputs to RNAV Systems:
   1. GPS
      1. RNAV systems using GPS input may be used as an alternate means of navigation guidance without ­restriction if appropriate RAIM is available.
      2. Operators of aircraft with RNAV systems that use GPS input but do not automatically alert the pilot of ­a loss of GPS, must develop procedures to verify correct GPS operation.
      3. RNAV systems using GPS input may be used as a substitute means of navigation guidance provided ­RAIM availability for the operation is confirmed. During flight planning, the operator should confirm the ­availability of RAIM with the latest GPS NOTAMs. If no GPS satellites are scheduled to be out-of-service, then ­the aircraft can depart without further action. However, if any GPS satellites are scheduled to be out-of-service, ­then the operator must confirm the availability of GPS integrity (RAIM) for the intended operation. In the event ­of a predicted, continuous loss of RAIM of more than five (5) minutes for any part of the route or procedure, the ­operator should delay, cancel, or re-route the flight as appropriate. Use of GPS as a substitute is not authorized ­when the RAIM capability of the GPS equipment is lost.
   2. WAAS
      1. RNAV systems using WAAS input may be used as an alternate means of navigation guidance without ­restriction.
      2. RNAV systems using WAAS input may be used as a substitute means of navigation guidance provided ­WAAS availability for the operation is confirmed. Operators must check WAAS NOTAMs.
   3. DME/DME/IRU
      1. RNAV systems using DME/DME/IRU, without GPS input, may be used as an alternate means of ­navigation guidance whenever valid DME/DME position updating is available.

4.. Recognizing, Mitigating and Adapting to GNSS Jamming and/or Spoofing

1. The low-strength data transmission signals from GNSSsatellites are vulnerable to various anomalies that ­can significantly reduce the reliability of the navigation signal. The GPS signal is vulnerable and has many uses ­in aviation (e.g., communication, navigation, surveillance, safety systems and automation); therefore, pilots ­must place additional emphasis on closely monitoring aircraft equipment performance for any anomalies and ­promptly inform Air Traffic Control (ATC) of any apparentGPS degradation. Pilots should also be prepared to ­operate without GNSS navigation systems.
2. GNSSsignals are vulnerable to intentional and unintentional interference from a wide variety of sources, ­including radars, microwave links, ionosphere effects, solar activity, multi-path error, satellite communications ­GNSSrepeaters, and even some systems onboard the aircraft. In general, these types of unintentional ­interference are localized and intermittent. Of greater and growing concern is the intentional and unauthorized ­interference of GNSSsignals by persons using “jammers” or “spoofers” to disrupt air navigation by interfering ­with the reception of valid satellite signals.
3. Manufacturers, operators, and air traffic controllers should be aware of the general impacts of GNSS ­jamming and/or spoofing which include, but are not limited to:
   1. Inability to use GNSS for navigation.
   2. Inability to use hybrid GNSS inertial systems for navigation.
   3. Loss of, or degraded, performance-based navigation (PBN) capability (e.g., inability to fly required ­navigation performance (RNP) procedures).
   4. Unreliable triggering of Terrain Awareness and Warning Systems (TAWS).
   5. Inaccurate aircraft position on navigation display (e.g., moving map and electronic flight bag).
   6. Loss of, or erroneous, Automatic Dependent Surveillance-Broadcast (ADS-B) outputs.
   7. Unexpected effects when navigating with conventional NAVAIDS (e.g., if the aircraft is spoofed from the ­intended flight path, autotuning will not select the nearby NAVAID).
   8. Unanticipated position-dependent flight management system effects (e.g., erroneous insufficient fuel ­indication).
   9. Failure or degradation of Air Traffic Management (ATM) infrastructure and its associated systems reliant ­on GNSS, resulting in potential airspace infringements and/or route deviations.
   10. Failure of, or erroneous aircraft clocks (resulting in inability to log on to Controller-Pilot Data Link ­Communications (CPDLC).
   11. Erroneous wind and ground speed indications.
4. When flying IFR, pilots should have additional navigation equipment for their intended route to crosscheck ­their position. Routine checks of position against VOR or DMEinformation, for example, could help detect a ­compromised GNSSsignal. Pilots transitioning to VOR navigation in response toGNSSanomalies should refer ­to the Chart Supplement U.S. to identify airports with available conventional approaches associated with the ­VOR Minimum Operational Network (MON) program. (Reference Aeronautical Information Publication AIP ­ENR 4.1-2.6.3).
5. Prior to departure, the FAA recommends operators to:
   1. Be aware of potential risk locations.
   2. Check for any relevant Notices to Airmen (NOTAMs).
   3. Plan fuel contingencies.
   4. Plan to use conventional NAVAIDs and appropriate arrival/approach procedures at the destination.
   5. Follow the detailed guidance from the respective Original Equipment Manufacturer (OEM).
6. During flight, the FAA recommends operators do the following:
   1. Be vigilant for any indication that the aircraft's GNSS is disrupted by reviewing the manufacturer's ­guidance for that specific aircraft type and avionics equipage. Verify the aircraft position by means of ­conventional NAVAIDs, when available. Indications of jamming and/or spoofing may include:
      1. Changes in actual navigation performance.
      2. Aircraft clock changes (e.g., incorrect time).
      3. Incorrect Flight Management System (FMS) position.
      4. Large shift in displayed GNSS position.
      5. Primary Flight Display (PFD)/Navigation Display (ND) warnings about position error.
      6. Other aircraft reporting clock issues, position errors, or requesting vectors.
   2. Assess operational risks and limitations linked to the loss of GNSS capability, including any on-board ­systems requiring inputs from a GNSS signal.
   3. Ensure NAVAIDs critical to the operation for the intended route/approach are available.
   4. Remain prepared to revert to conventional instrument flight procedures.
   5. Promptly notify ATC if they experience GNSSanomalies. Pilots should NOT normally inform ATC of ­GNSS jamming and/or spoofing when flying through a knownNOTAMed testing area, unless they require ATC ­assistance. (See AIP ENR 4.1-22.)
7. Post flight, the FAA recommends operators to:
   1. Document any GNSS jamming and/or spoofing in the maintenance log to ensure all faults are cleared.
   2. File a detailed report at the reporting site: Report a GPS Anomaly Federal Aviation Administration,
      www.faa.gov/air_traffic/nas/gps_reports.