Equipment Required Notes on IFR Procedure Charts

FAA and members of the aviation community have almost completed a long process for updating the equipment required notes on IFR charts. In particular, FAA is consolidating and adding detail about performance based navigation (PBN) requirements.

For background on this topic, see New Equipment Required Notes and the topic 13-02-312: Equipment Requirement Notes on Instrument Approach Procedure at the Aeronautical Charting Meeting.

But FAA still hasn’t clearly addressed the confusion that many pilots have about when and how an IFR-approved GNSS (i.e., a “suitable RNAV system” as described in the AIM and various ACs–specifically, AC 90-100, paragraph 7) supplants the need for conventional avionics, such as DME and ADF.

For example, see the KBEH ILS or LOC RWY 28 approach chart.

The equipment notes say that RNAV-1 GPS (i.e., either a non-WAAS or WAAS GNSS) is required to fly the procedure. A second note says that DME is required if you fly the LOC-only procedure, a non-precision approach to an MDA with a missed approach point identified by a DME fix. Other waypoints along the final approach segement include WESUG and the visual descent point (VDP), each defined as a DME fix.

The notes seem to imply that if you fly the LOC-only version of this procedure, you must have DME. That is, if you have an IFR-approved GNSS, you must also have DME to fly the non-precision version of the procedure—you can’t use GNSS to substitute for the DME requirement unless you have a second GNSS that you can use to load the I-BEH localizer as a fix to provide distance information from the location of that DME transmitter. But that interpretation would make it impossible for most new aircraft (which don’t typically come with DME) or aircraft retrofitted with GNSS avionics and no DME to fly the LOC approach.

If you load that procedure into an IFR-approved navigator such as the Garmin GNS 750, the flight plan includes the following fixes:

You can use the distances shown relative to the FAF and the RW28 MAP to determine your along-track distance (ATD) to the VDP and the MAP, as described in the AIM and other references. You don’t need DME to identify the key fixes (and VDPs aren’t included in databases, so you must use ATD, either from a GPS or DME, to determine your position relative to a VDP).

Both AIM 1−2−3 Use of Suitable Area Navigation (RNAV) Systems on Conventional Procedures and Routes and AC 90-108 (it has the same title as the AIM paragraph) state:

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…


1. The allowances described in this section apply even when a facility is identified as required on a procedure (for example, “Note ADF required”).

That guidance apparently is too subtle. AOPA has flagged this issue at least three times in written comments to FAA about the PBN requirements box. As an AOPA representive confirmed, “It is not necessary to add a ‘DME required’ note if RNAV-1 GPS is also required to fly the approach.”

AOPA has more information on this topic here and in a fact sheet.

FAA is aware of the confusion current notes cause, and my contacts at AOPA are checking with FAA to see if the agency is making progress on clarifying the language used in the notes and guidance such as the AIM and ACs.

AIM Update: Approach Categories

FAA has released the January 30, 2020 update to the AIM. (Link to PDF and HTML editions here. You can read the explanation of changes here.)

The update includes several items of interest to IFR pilots, but one is of particular note here:

5−4−7. Instrument Approach Procedures
This change provides pilots with additional options when it is necessary to conduct an instrument approach at an airspeed higher than the maximum airspeed of its certificated aircraft approach category. It explains the flexibility provided in 14 CFR and emphasizes the primary safety issue of staying within protected areas.

Here’s the new text in that section:

a. Aircraft approach category means a grouping of aircraft based on a speed of Vref at the maximum certified landing weight, if specified, or if Vref is not specified, 1.3Vso at the maximum certified landing weight. Vref, Vso, and the maximum certified landing weight are those values as established for the aircraft by the certification authority of the country of registry. A pilot must maneuver the aircraft within the circling approach protected area (see FIG 5−4−29) to achieve the obstacle and terrain clearances provided by procedure design criteria.

b. In addition to pilot techniques for maneuvering, one acceptable method to reduce the risk of flying out of the circling approach protected area is to use either the minima corresponding to the category determined during certification or minima associated with a higher category. Helicopters may use Category A minima. If it is necessary to operate at a speed in excess of the upper limit of the speed range for an aircraft’s category, the minimums for the higher category should be used. This may occur with certain aircraft types operating in heavy/gusty wind, icing, or non−normal conditions. For example, an airplane which fits into Category B, but is circling to land at a speed of 145 knots, should use the approach Category D minimums. As an additional example, a Category A airplane (or helicopter) which is operating at 130 knots on a straight−in approach should use the approach Category C minimums.

c. A pilot who chooses an alternative method when it is necessary to maneuver at a speed that exceeds the category speed limit (for example, where higher category minimums are not published) should consider the following factors that can significantly affect the actual ground track flown:

1. Bank angle. For example, at 165 knots ground speed, the radius of turn increases from 4,194 feet using 30 degrees of bank to 6,654 feet when using 20 degrees of bank. When using a shallower bank angle, it may be necessary to modify the flight path or indicated airspeed to remain within the circling approach protected area. Pilots should be aware that excessive bank angle can lead to a loss of aircraft control.

2. Indicated airspeed. Procedure design criteria typically utilize the highest speed for a particular category. If a pilot chooses to operate at a higher speed, other factors should be modified to ensure that the aircraft remains within the circling approach protected area.

3. Wind speed and direction. For example, it is not uncommon to maneuver the aircraft to a downwind leg where the ground speed will be considerably higher than the indicated airspeed. Pilots must carefully plan the initiation of all turns to ensure that the aircraft remains within the circling approach protected area.

4. Pilot technique. Pilots frequently have many options with regard to flight path when conducting circling approaches. Sound planning and judgment are vital to proper execution. The lateral and vertical path to be flown should be carefully considered using current weather and terrain information to ensure that the aircraft remains within the circling approach protected area.

New T-Routes in the PNW

FAA added several new T-Routes in the Pacific Northwest on January 30, 2020, and other routes there and throughout the U.S. were expanded.

T-routes are described in AIM 5−3−4. Airways and Route Systems and elsewhere in the AIM, ACs, and other documents. They are low-altitude RNAV routes (shown in blue on enroute charts) similar to the victor airways based on VORs, but T-routes require GNSS and are available to aircraft with a suitable RNAV system–viz., an IFR-approved GPS. T-Routes originally were intended to provide efficient paths for IFR traffic through busy Class B airspace (see this briefing from AOPA), but as FAA shifts from VOR-based navigation to PBN, T-routes are becoming more common throughout the national airspace system.

For example, here’s a segment of T268 (click the preceding link to see the route at, a new route from the Seattle area across the Cascades to Spokane, WA and beyond.

T268 from Seattle to Spokane

This new route closely parallels the V2 airway, but because it can zig and zag a bit around high terrain, it offers lower MEAs, which can be helpful when avoiding ice. Compare the GNSS-based MEAs (in blue) below with the MEAs for the VOR-based V2 airway.

Another section of T268 provides an efficient route from the area around Paine Field (KPAE) north of Seattle east across the Cascades while remaining clear of the increasingly busy airspace that surrounds Seattle.

Another excellent example of how a T-route can offer advantages over VOR-based airways is the stretch between the Redmond-Bend area in Oregon south toward Reno and Las Vegas.

A segment of T274

The new T274 closely follows V165, but well-placed bends allow the MEA to drop, for example, from 14000 ft to 10100 ft. That’s potentially a big help, both for avoiding icing and for reducing the need for oxygen.

Compare the MEAs for the T-route and victor airway

If you fly IFR and haven’t closely reviewed the low-altitude enroute charts recently, take another look. You may find new T-routes that give you new options in the areas where you fly.

FAA publishes T-routes and other changes to airspace in the Federal Register. You can find the complete list of the January 2020 changes here.

AOPA Proposes IPC Changes

AOPA has asked FAA to remove two tasks from the requirements to complete an instrument proficiency check (IPC):

  • Demonstrate a circle-to-land approach and
  • Landing from an instrument approach

Eliminating these two tasks would make it possible to accomplish an IPC entirely in an ATD or FTD. You can read AOPA’s detailed proposal here.

The change would also complement the update to the IFR currency rules that FAA published in 2018. The items required for an IPC are listed in a task table in Appendix A of the Instrument Rating ACS, and the update to the regulations caused some confusion, which I wrote about here and here.

IPC Requirements Table


Garmin has published a video that explains the VNAV features added to the GTN series in 2018 (see New Garmin GTN Features).

The Runway Environment in the RNAV Era

As of January 30, 2020, the FAA had published 4,048 RNAV (GPS) approaches with LPV (localizer performance with vertical guidance) minimums at 1,954 airports; 1,186 of those airports are not served by an ILS. The number of LPV-capable procedures is almost three times the 1,550 approaches with Category I ILS minimums, and 2,838 of the procedures with LPV minimums serve runways without an ILS,

For the latest totals, visit the Instrument Flight Procedures (IFP) Inventory Summary and Satellite Navigation — GPS/WAAS Approaches pages at the the FAA website.

This capability to fly ILS-like procedures to thousands of runways at small-town and rural airports is a boon to IFR pilots. But you must carefully prepare to fly approaches to runways that don’t have the ground infrastructure associated with an ILS–most importantly an approach lighting system and accessories such centerline and touchdown zone lighting. And keep in mind that a non-ILS runway may not be as a long as you’re accustomed to–the minimum length for a runway served by an approach with LPV minimums is just 3200 ft. (more details here).

For more information about GPS-based approaches, see Required Navigation Performance (RNP) Approaches (APCH) .

For example, here’s video of the final approach segment of the RNAV (GPS) RWY 16 procedure at Chehalis, WA (KCLS) during a night approach.

As the video shows, the runway can be hard to spot. It has REILs and a PAPI, but it’s in a dark area near a river. And you must remember to activate the lights by clicking the transmit button on the CTAF as you approach the airport. (The camera makes the scene look a little darker than it really was to human eyes–but you get the idea.)

Chehalis (KCLS) airport

That approach has an LPV decision altitude of 476 ft MSL (300 ft. AGL). The visibility requirement is 1 sm. That’s not much greater than the 200 ft DA and 1/2 sm visibility for a typical Category 1 ILS. But the environment is vastly different than that presented by an ILS runway with its bright lights and other big-city features.

Here’s an overview of the approach lighting systems associated with ILS procedures.

Instrument Procedures Handbook:
Figure 9-36. Precision and nonprecision ALS configuration.

Contrast the view at KCLS with the scene at Boeing Field (KBFI) in Seattle during the final stages of an ILS approach.

ILS RWY 14R at Boeing Field (KBFI)

Here’s an approach to runway 20 at Bremerton, WA (KPWT). KPWT is a non-towered airport, but runway 20 is served by an ILS approach, which includes an ALS.

RNAV RWY 20 approach at KPWT

So, regardless of the type of approach you’re flying, make sure you review and prepare for the runway environment that you’ll encounter when you break out of the clouds and go visual. It’s especially important to know which of the visual cues described by 14 CFR §91.175 Takeoff and landing under IFR will be available.

Calling ATC for an IFR Clearance

The weather was barely VFR at Chehalis, WA (KCLS) for this night takeoff, so I called Seattle Center on the phone to get my IFR clearance and release for a flight back to Boeing Field (KBFI).

In 2019, FAA finished publishing ATC telephone numbers in the Chart Supplement, so you can get an IFR a clearance (or cancel IFR) directly with ATC, not via FSS, when operating at a non-towered airport or when a tower is closed.

You can listen to this process at the beginning of the video below and then follow along as I fly the ILS RWY 14R at Boeing Field (KBFI).

The audio panel/intercom in the A36 Bonanza supports a Bluetooth connection to my phone, so I’m able to speak and hear through my headset during phone calls. That feature makes it especially easy to contact ATC, in this case Seattle Center.