Equipment and Performance Requirement Notes on Instrument Approach Procedures

The Issue

Instrument approach procedure charts provide a wealth of information to enable pilots to fly approaches safely in instrument conditions, but sometimes the charts can be confusing. The FAA, general aviation associations, and the charting industry have been working to update the charts to make it easier for pilots to look at the chart and know immediately what kind of navigation is required for the entire approach and any segment of the approach.

Beginning in August 2017, the FAA will be adding a box near the top of the approach chart, above the briefing area, that lists the type of navigation equipment necessary to enter the procedure and to fly any portion of the procedure. The addition of the box will be phased in as new procedures are added and existing procedures amended. The title of the approach chart will list the navigation system used to provide lateral navigation guidance within the final approach segment, such as ILS or LOC. A recent policy change has led to the removal of equipment requirements from the title that may still be necessary to fly the approach, such as for the missed approach. Another change will be the charting of the PBN navigation specification required to fly the procedure, discussed in greater detail below.

The area, called the equipment requirements box for conventional procedures and the Performance Based Navigation (PBN) requirements box for RNAV procedures, will be the only area on the chart that lists the additional equipment or performance requirement needed for the approach. Currently, equipment and performance requirements can be found in the briefing strip and the planview area, and the two don’t always list the same types of navigation equipment as being required, which can create confusion.

Background

The FAA’s historical charting policy has been to note any equipment required for procedure entry from the en route environment in the planview of the procedure (e.g., RADAR REQUIRED or ADF REQUIRED). Should equipment be required on portions of the procedure outside the final approach segment, including the missed approach, a note would be charted in the notes box of the pilot briefing strip of the approach chart (e.g., ADF REQUIRED or DME REQUIRED). The title of the procedure always listed the equipment required to fly the final approach segment (e.g., ILS or LOC).

In 2013, the National Business Aviation Association (NBAA) brought to the Aeronautical Charting Forum a proposal that the FAA “chart all equipment requirement notes in a single location.” The forum discussed the idea and came to a consensus in 2016. The new charting policy was published in the FAA Order 8260.19H, effective July 20, 2017, with implementation expected to begin in August 2017. Only a few charts will be changed over the next few months; however, beginning with the March 29, 2018 chart cycle, almost all new and amended procedures will include the new requirements box. It’s important to understand that a complete conversion to the new format may take several years; therefore, chart users must remain familiar with both charting formats.

AOPA's Position

AOPA has been involved in the collaborative discussions with NBAA and the FAA to reorganize the charts to be easier to read for all instrument-rated pilots. This charting change will allow pilots to quickly determine the navigation equipment required to fly a procedure and remove the need to search the chart for equipment requirement notes. This change will not increase the requirements for any procedure and is solely a reorganization of information to a consistent location. AOPA participates in the Aeronautical Charting Forum , is a member of the Performance-based Operations Aviation Rulemaking Committee (PARC), and works closely with the FAA on charting changes.

Requirements Box Notes Explained

The new charts will clearly state in the requirements box what is required to execute the procedure, such as, “ADF Required for Procedure Entry.” If multiple options are available for procedure entry, the area will list each, separated with “or”: “ADF or DME Required for Procedure Entry.” For approaches that require other navigation equipment for certain segments, they will be listed as well. For example, “DME Required for LOC Only.” Also, on a non-NDB approach that requires an ADF for one part of the segment, perhaps the intermediate or missed approach or both, it would simply say, “ADF Required.” Pilots can use an IFR-certified GPS receiver in lieu of DME and ADF for most IFR operations, discussed further in this fact sheet.

There may be multiple or a combination of notes necessary to support varying requirements. The FAA will publish the equipment requirement stating the particular portion(s) of the instrument procedure to which the equipment requirement applies in an easy to understand format, like how they are published today. It will be assumed that all aircraft flying IFR are equipped with at least one VOR, as it is today, so there will not be a note stipulating that a VOR is required.

Below are several examples (not all inclusive) of how a note may appear in the requirements box for a conventional or RNAV procedure requiring specific equipment for procedure entry from the en route environment.

1. “RADAR Required For Procedure Entry”
2. “ADF Required For Procedure Entry”
3. “DME Required For Procedure Entry”
4. “ADF OR DME Required For Procedure Entry”
5. “RNAV 1-DME/DME/IRU or GPS or Radar or DME Required For Procedure Entry”
6. “RNAV 1-GPS or RADAR Required For Procedure Entry”
7. “RNAV 1-DME/DME/IRU or GPS or RADAR Required For Procedure Entry”
8. “Aircraft Not DME/DME/IRU or GPS Equipped - RADAR Required For Procedure Entry” or, if applicable, “Aircraft Not GPS Equipped - RADAR Required For Procedure Entry”

Below are examples of notes published when other navigation equipment is required to complete the approach, including the missed approach (e.g., VOR, ILS, or other non-ADF approaches requiring ADF or DME for the intermediate and/or missed approach segments).

1. “DME Required” (i.e., DME is required for the intermediate segment or both the intermediate and missed approach segments)
2. “ADF Required” (i.e., ADF is required for the intermediate segment or both the intermediate and missed approach segments)
3. “DME Required For LOC Only.” (i.e., LOC procedure published on the same chart with an ILS and DME is required for defining the FAF)

Should an ATC surveillance system also be available for vectoring an aircraft to a segment of an instrument approach, the FAA can use the word “or” to identify this an option.

1. “ADF or RADAR required for (segment of approach),” (i.e., if ADF is required for the segment of the approach and/or RADAR is available)
2. “ADF or DME or RADAR required for (segment of approach),” (i.e., if ADF or DME is required for the segment of the approach and/or RADAR is available)

It is common for some VOR-only procedures to include two sets of minimums: one for VOR-only guidance and another lower minimum if a RADAR identified fix can be established. Where RADAR is the only method of determining or defining a terminal fix, the FAA will chart the note: “RADAR Required To Define (fix name).”

The FAA is integrating RNAV segments into ILS, LOC, and GLS procedures to maximize the benefits of procedure design and efficiency that comes with RNAV. For those ILS, LOC, or GLS procedures that require RNAV for at least one segment, such as the missed approach, the FAA will note the PBN requirements for those PBN segments. The notes below would be appropriate if PBN is required for all other initial approach segments of the procedure and/or the missed approach. 

1. “RNAV 1-DME/DME/IRU or GPS Required”
2. “RNAV 1-GPS Required.”
   
   If PBN is only required for one initial approach segment (assume another conventional initial approach segment exists), then the note would be prefaced with the fix:
   
   
3. “From (fix name): RNAV 1 DME/DME/IRU or GPS Required”

PBN Navigation Specification (NavSpec)

The PBN concept represents a shift from sensor-based to PBN-based navigation capabilities. A navigation specification is a set of aircraft and pilot requirements needed to support a navigation application for a defined airspace or procedure. The PBN concept specifies that aircraft navigation system performance requirements be defined in terms of their accuracy, integrity, continuity and functionality. Performance requirements are identified in navigation specifications, as are the choice of navigation sensors and equipment that may be used to meet the performance requirements. More simply, NavSpecs are a set of aircraft, pilot and operating conditions that must be met to accomplish a procedure designed to that NavSpec. An example NavSpec is RNP 1. NavSpecs that require on-board navigation monitoring and alerting use the label RNP, while those that do not require such performance monitoring use the label RNAV. 

Many IFR pilots are familiar with WAAS which falls within the FAA’s category of PBN. WAAS GPS systems use satellites and onboard equipment to navigate. This onboard equipment conducts performance monitoring and can alert the pilot to position errors, which allows it to meet the requirements for more advanced forms of RNAV or RNP. An RNP specification includes a requirement for on-board performance monitoring and alerting, while an RNAV specification does not.

According to the Aeronautical Information Manual, 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 aircraft operating within the airspace, route, or procedure. For example, RNAV 1 is typically used for missed approaches and denotes that the aircraft must maintain a total system error of not more than 1 NM for 95 percent of the total flight time. It is important for a pilot flying these procedures to know which NavSpec they can operate under. Pilots should reference their avionics handbooks, POH, or AFM as needed for information specific to their aircraft’s capabilities.

As part of this charting change, the FAA will now be including the most restrictive NavSpec to fly that PBN procedure and that PBN portion (segment) published on a conventional procedure. All PBN procedures, including RNAV, RNP, GLS, and RNAV to ILS/LOC approach procedures, will have an annotation detailing the PBN NavSpec to indicate the appropriate qualification required to conduct the instrument procedure.

1. “RNAV 1”
2. “RNP 1”
3. “A-RNP”
4. “RNP APCH”
5. “RNP AR APCH”
6. “RNP 0.3”

_{Note: Scalability is indicated by a range of RNP values (e.g., an RNP AR APCH can scale from RNP 1 to 0.1 NMs)}

_{This table lists the NavSpec that will be charted with the corresponding RNAV or RNP titled procedure. NavSpecs are further discussed in AC 90-100A - U.S Terminal and En Route Area Navigation (RNAV) Operations, and AC 90-105A - Approval Guidance for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System and in Oceanic and Remote Continental Airspace.}

_{Note 1: When GDU software version 13.00 or later is installed.
Note 2: When main processor software version 3.30 or later is installed.
Note 3: When main processor software version 2.3 or later is installed.}

_{Understanding the NavSpec your system is authorized and capable of flying is important. This table, sourced from information from Garmin, provides examples of the various performance requirements these systems are capable of flying. Pilots should consult current manufacturer guidance to determine the NavSpecs one can fly.}

When the PBN approach procedure contains advanced PBN functions, which are in addition to what is required in the PBN NavSpec, the procedure will be annotated with the advanced function.

1. “RF Required” (RF stands for Radius to Fix, a type of leg transition discussed in AC 90-105A)

Sources for all charts: FAA unless noted otherwise

Updated September 13, 2018