An IFR Flight: KBFI-KUAO

Ride along on this typical IFR flight from Boeing Field (KBFI) in Seattle to visit Pacific Coast Avionics at Aurora, OR (KUAO), south of Portland. The video (link below) includes ATC communications and shows the rhythm of a typical IFR flight: Clearance, Takeoff and Departure, Enroute, Descent, and Approach.

As you’ll see in the video, I filed a preferred route used for low-altitude IFR traffic between the Seattle and Portland areas. I also pass along tips for copying IFR clearances and ATIS/AWOS information.

Leaving KBFI, I flew the NRVNA ONE departure, an RNAV procedure. At KUAO, I flew the RNAV (GPS) RWY 35 approach to get below a solid cloud layer that topped out at around 4000 ft.

I hope you enjoy the views of cloud surfing along the way as I use the Garmin G500 TXi, GTN 750Xi, and GFC 600 autopilot.

Video of the return flight from KUAO to KPWT (for fuel) is here.

Setting a Course v. Vectors to Final

I am not a fan of the vectors to final (VTF) option when loading instrument approaches in GPS navigators like the Garmin GNS and GTN series avionics.

As a general rule, avoid the vectors (vectors-to-final) option

Even with recent improvements to how the Garmin GTN series boxes handle VTF, it’s usually best to choose an initial fix (IF) or initial approach fix (IAF) based on the direction from which you’re arriving in the terminal environment, and then, depending on your clearance from ATC, activate a leg of the procedure or proceed direct to an IF or IAF. See the example at KMWH below.

Choosing a transition (IF) when loading an approach.

For more information about VTF, see Avoiding the Vectors-to-Final Scramble, Changes to Vectors-to-Final in Garmin GTN System 6.x, Flying Instrument Approaches without Activating the Approach, and Joining a Localizer from Afar.

Occasionally, however, you may encounter an approach such as the ILS or LOC RWY 14R at Boeing Field (KBFI) (chart below).

Video of the approach described in this discussion

Knowing how to use a handy technique that straddles the line between the VTF and setting a specific course (a variation on OBS mode) can help you smoothly join the final approach course. Bear with me for a somewhat convoluted explanation.

For more information about setting a specific course to a fix and the OBS feature, search for Direct To and OBS in the pilot guide for the avionics you use.

ILS or LOC RWY 14R at KBFI

The plan view for this approach shows two key fixes along the localizer: ISOGE and TOGAE.

Plan view

TOGAE is step-down fix with a crossing restriction and a GS intercept altitude at 1600 (the beginning of the final approach segment when you fly the full ILS with glideslope). TOGAE also serves as the FAF when you fly the LOC-only version of the procedure.

In theory, Seattle Approach could vector you to join the localizer a few miles outside TOGAE (within the approach gate; see the Instrument Procedures Handbook and the P/C Glossary).

APPROACH GATE− An imaginary point used within ATC as a basis for vectoring aircraft to the final approach course. The gate will be established along the final approach course 1 mile from the final approach fix on the side away from the airport and will be no closer than 5 miles from the landing threshold.

Definition of approach gate in the P/C Glossary

The approach also chart shows ISOGE, a fix 9 nm from the ruwnay, as an IF/IAF. (You will never fly the depicted hold/course reversal anchored at ISOGE.)

And ISOGE appears in the list of transitions when you load this approach in a GPS navigator such as a Garmin GTN 750.

If you choose either Vectors or ISOGE, the fix appears in the flight plan.

If you activate VTF for this approach, the GTN draws an extended centerline from TOGAE (the FAF) out along in the localizer course. But you loose ISOGE as a reference.

VTF leaves ISOGE in the flight plan, but all distance and ETE information references TOGAE.

If you activate the approach with ISOGE as the transition, the navigator draws a magenta line from your present position to ISOGE, and if you hand-fly that course or put the autopilot in NAV mode, you will head directly to that fix.

But Seattle Approach always issues a series of vectors to sequence you into the flow of traffic for KBFI and to avoid conflicts (wake turbulence and otherwise) with airliners aiming for nearby KSEA. Regardless of the direction from which you’re arriving, ATC places you on the localizer at least a few miles outside of ISOGE.

In other words, you don’t want to go direct to ISOGE, and it’s helpful to have a reference to the localizer course as ATC vectors you into the flow.

For example, I recently flew the ILS from the area near Arlington, WA (KAWO) northeast of Seattle (video here).

Radar vectors KAWO-KBFI to the ILS or LOC RWY 14R

This typical routing from the northeast involves a long vector on a southwest heading to intercept the localizer. Even if you have the navaid tuned, you may not be able to identify it and confirm its appearance on the CDI until you are almost on top of the course. If ATC is busy or if you’re flying a fast airplane, it’s easy to blow through the localizer or be tempted to make an aggressive turn to capture it when you get the final vector from ATC.

(For another demonstration of this technique, see the video below.)

Here’s the “trick” to help you fly a smooth intercept. It involves setting a specific course direct to a fix–in other words, it’s similar to using OBS mode:

• If you’re using the autopilot, make sure you’re in HDG mode to follow vectors from ATC.
• Because you’re flying vectors to join the localizer, confirm that you’re showing “green needles” on the HSI or CDI used to fly the ILS. You don’t need GPS guidance from this point on.
• Load the approach with ISOGE as the transition (i.e., as the first fix in the procedure).
• Confirm the list of fixes in the flight plan.
• Select ISOGE and choose direct-to.
• In the direct-to window, enter the course inbound to ISOGE along the localizer–135 degrees.
• On the map, you’ll see a magenta line extending to ISOGE along the course 135 degrees–in effect, an extension of the localizer.

Here’s how that sequence looks using a GTN 750:

ISOGE selected as the transition (initial fix). ISOGE is the current direct-to fix–the approach is activated.

The GTN 750 shows guidance direct to ISOGE. But ATC is vectoring you to join the final approach course at a point outside ISOGE.

To draw an extension of the localizer from ISOGE, select ISOGE again, choose Direct-To, and enter the course 135.

Setting a specific course to ISOGE.

The GTN draws a course of 135 to ISOGE, in effect, an extension of the localizer.

Now you can monitor your progress toward the final approach course and prepare for the turn onto the localizer, even if you’re not currently receiving the signal or showing a flyable localizer CDI.

Joining the localizer.

As you join the localizer and then pass ISOGE, the GTN sequences to the next fix in the approach, TOGAE. If you used OBS mode to set a course to ISOGE, the GTN would suspend waypoint sequencing past ISOGE, but setting a direct-to course preserves that feature.

On the ILS approaching TOGAE.

Garmin Updates GTN Trainer App

Garmin has updated the free GTN Trainer app for the iPad. The new version reflects system software 6.62, which includes features added since version 6.5, such as vertical navigation, along track offsets and more.

You can find a detailed discussion of some of these functions at New Garmin GTN 750 Features.

New GTN Guides

Pilot Workshops has published updated versions of its Pilot-Friendly manuals for the Garmin GTN 750 and GTN 650 touch-screen navigators. More details and samples here.

Full disclosure: I was the primary author of the new GTN editions, with a lot of help from the editors and graphics staff at Pilot Workshops. I also contribute to the company’s IFR and VFR training scenarios.

The books are available both in spiral-bound print editions and as PDFs.

Use of GPS on Conventional Approaches (Update)

Users of Garmin GTN and GNS navigators may now use the GPS CDI as an alternate means of guidance along the final approach course of a VOR or NDB approach, provided they monitor the ground-based navaid to ensure that they’re tracking the proper final approach course. Previous editions of the AFM supplement for GTN and GNS avionics required you to display the VOR CDI on your HSI or PFD even if you could monitor the ground-based navaid on a separate CDI or by using a bearing pointer.

Note that you must still display the VOR/LOC (“green needles”) CDI to fly the final approach segment of an approach based on a localizer or any other type of navaid except a VOR or NDB.

For more information about setting the CDI while flying approaches, see
Setting the CDI on a Conventional Approach (The “Kill Switch”). For general background, see Use of Suitable Area Navigation (RNAV) Systems on Conventional Procedures and Routes

The updated language in the AFM supplement for the GTN and GNS series (see below) synchronizes the limitations in the AFM supplement with a 2016 update to AIM 1−2−3. Use of Suitable Area Navigation (RNAV) Systems on Conventional Procedures and Routes (see Use of IFR GPS on Conventional Approaches).

In March 2020, Garmin also updated the AFM supplements for the GNS 530W and GNS 430W to reflect this change. See the 190-00357-03_g version of that document, available at the Garmin website.

The change came with a recent update to the system software for the GTN line of GPS navigators (more information about the new features at BruceAir here).

The new software brings a significant change to the language in the approved Airplane Flight Manual Supplement for the GTN boxes (the PDF of the new AFM supplement for the GTN 750 is available here).

Section 2.10 Instrument Approaches in that AFM supplement now notes the following:

…c) The navigation equipment required to join and fly an instrument approach procedure is indicated by the title of the procedure and notes on the IAP chart. Navigating the final approach segment (that segment from the final approach fix to the missed approach point) of an ILS, LOC, LOC-BC, LDA, SDF, MLS, VOR, TACAN approach, or any other type of approach not approved for GPS, is not authorized with GPS navigation guidance. GPS guidance can only be used for approach procedures with GPS or RNAV in the procedure title. When using the Garmin LOC/GS receivers to fly the final approach segment, LOC/GS navigation data must be selected and presented on the CDI of the pilot flying. When using the VOR or ADF receiver to fly the final approach segment of a VOR or NDB approach, GPS may be the selected navigation source so long as the VOR or NDB station is operational and the signal is monitored for final approach segment alignment. [Emphasis added]

A test of the new software in the free Garmin PC-based trainer indicates that the message warning the pilot to switch the CDI from GPS to VOR has also been removed. The following captures show the VOR-A approach at Paine Field (KPAE) north of Seattle flown with the CDI with GPS selected. Note the cyan bearing pointer behind the magenta GPS CDI.

New Garmin GTN 750 Features

Garmin has released system software 6.50 (since updated to 6.51, which is a mandatory update) for its GTN 750 and GTN 650 navigators. The new software adds several features, including:

• Vertical navigation (VNAV) capability when flying STARS and the initial stages of instrument approaches
• Along-track offsets in flight plan segments
• Destination airport remains in the flight plan when an approach is loaded (but the destination airport is removed when the approach is activated)
• A shortcut to the airport info page added to all procedure headers
• Load the approach NAV frequency from the approach header in the flight plan
• QWERTY keyboard option

The following sections highlight some of these features. For more details on how to use the functions, see the latest editions of the GTN guides, available in my Aviation Documents folder at OneDrive and from Garmin’s product pages.

The details about this update to the GTN series are in ASDN Service Bulletin 1860, the 6.51 mandatory udpate, and the GTN 725/750 SOFTWARE v6.50 PILOT’S GUIDE UPGRADE SUPPLEMENT.

Garmin also released system software updates for the G500/600 PFD/MFD and associated hardware. For details on those updates, see ASDN Service Bulletin 1861.

Garmin has also updated its free Windows-based trainer for the GTN series.

Note that these system updates must be performed by an authorized Garmin dealer or avionics shop unless you are flying a experimental-homebuilt aircraft.

VNAV Capability

The new software adds several vertical navigation features, best illustrated with examples.

Garmin has published a video that describes the VNAV feature in detail, here.

Suppose you are flying the RNAV RWY 08 approach at Lewiston, ID (KLWS), joining the procedure at the BIDDY initial approach fix northwest of the airport. The NoPT feeder route from BIDDY specifies an an altitude of at or above 5000 ft to EVOYU, followed by a descent to at or above 4000 ft to MABIZ, and then at or above 3400 ft to the FAF at GIYES.

With the new GTN system software, those segment altitudes appear in the flight plan page for the procedure.

The VNAV feature appears as a magenta vertical guidance cue next to the altitude tape on a PFD such as the new Garmin G500Txi (shown here) or the G500. Note that at this point in the approach, the LPV glidepath is a dim white diamond behind the magenta VNAV cue because the FAF is not the active waypoint and LPV is not yet annunciated on the HSI.

The VNAV cue provides advisory guidance to help you smoothly descend to each charted altitude as you fly the initial stages of the approach.

The LPV glidepath marker that displays approved vertical guidance replaces the VNAV cue when the FAF is active and the GTN system confirms that LPV minimums are available, as shown below.

Similar VNAV information and cues are available when flying a STAR, such as the MADEE FOUR arrival at Bellingham, WA (KBLI).

Note that the altitudes shown in the GTN flight plan list for this STAR are for turbojet aircraft. But you can easily edit the altitude if ATC assigns a more appropriate altitude when you’re flying a typical piston-powered light aircraft.

If you are flying an approach based on an ILS, LOC, or VOR, you can quickly retrieve the navaid frequency by touching the approach title, as shown below for the ILS RWY 16 at KBLI.

Along-Track Offsets

Suppose you are flying northeast along V2 at 13,000 ft. between ELN and MWH when Seattle Center clears you to cross 20 nm west of MWH at 9000 ft.

With the new software, you can easily enter an along-track offset and display advisory vertical guidance to help you meet the restriction.

Touch MWH in the flight plan, and then touch the new Along Track button.

To create a waypoint for VNAV guidance, fill in the information that corresponds to your new clearance.

Airport Information

An earlier version of the GTN system software included behavior that frustrated many pilots. When you loaded an approach into a flight plan, the destination airport was removed. If you hadn’t noted details such as the tower frequency, extracting that information from the GTN’s database was cumbersome.

In version 6.50, Garmin has added an APT Info button next to the approach title in the flight plan list.

Touching that button shows the familiar information window that provides touch access to details about the airport, including frequencies, weather, and other data.

QWERTY Keyboard

You can also choose a QWERTY keyboard instead of the alphabetical layout in previous versions of the GTN software. The option is available on the System Setup page.

Garmin Guidance on Database Updates

Garmin has published guidance for updating its GTN avionics with a Flight Stream and Database Concierge. Web page here; PDF here.

The Flight Stream 510, an SD card that is Wi-Fi and Bluetooth enabled, works with GTN-series avionics. It provides a wireless connection to the GTN to update databases and to provide GPS and ADS-B information to apps such as ForeFlight and Garmin Pilot. The FS510 is part of the Garmin Connext series of products and services.

 

Garmin GTN Avionics and RF Legs

The release of updated operating software for Garmin GTN-series avionics brings new capabilities to many typical general aviation pilots who fly under IFR. One of the new features is the ability to fly curved radius-to-fix (RF) legs on some instrument approaches.

To learn more about the capabilities of Garmin panel-mount avionics, including the various G1000 and GTN-series products, see Garmin Performance-Based Navigation Capabilities (PDF), a brochure published by Garmin.

Until recently, RF legs were published only on so-called RNP procedures with authorization required (AR) restrictions (for more information, see AIM 5−4−18: RNP AR Instrument Approach Procedures). But FAA has started publishing some approaches with RF legs (like the example above) that are not designated as RNP AR procedures. And, with some limitations, pilots who fly aircraft equipped with GTN-series avionics should be able to fly the RF legs used as transitions/feeder routes on those approaches. (Note that so far, these approaches don’t require RF capability–conventional transitions/feeder routes and/or radar vectors are also available.)

For more information about RF legs, see RNP Procedures and Typical Part 91 Pilots and Garmin Radius to Fix Leg Project Report here at BruceAir. For additional background on GPS navigation and RNP procedures, see also Updated AC 90-105A.

The revised STC for the GTN series (document 190-01007-A5) notes that:

GPS/SBAS TSO-C146c Class 3 Operation
…The Garmin GNSS navigation system complies with the equipment requirements of AC 90-105 and meets the equipment performance and functional requirements to conduct RNP terminal departure and arrival procedures and RNP approach procedures including procedures with RF legs subject to the limitations herein [emphasis added].

Sections 2.12 RF Legs and 2.13.1 RNP 1.0 RF Leg Types of the STC add the following information:

2.12 RF Legs
This STC does not grant operational approval for RF leg navigation for those operators requiring operational approval. Additional FAA approval may be required for those aircraft intending to use the GTN as a means to provide RNP 1 navigation in accordance with FAA Advisory Circular AC 90-105. [Note that per AC 90-105A, domestic Part 91 operations do not require additional approval–only Part 91 subpart K operations and commercial operations need LOAs or the equivalent FAA approval.]

The following limitations apply to procedures with RF legs:

• Aircraft is limited to 180 KIAS while on the RF leg
• RF legs are limited to RNP 1 procedures. RNP AR and RNP <1 are not approved
• Primary navigation guidance on RF legs must be shown on an EHSI indicator with auto-slew capability turned ON
• GTN Moving Map, EHSI Map, or Distance to Next Waypoint information must be displayed to the pilot during the RF leg when flying without the aid of the autopilot or flight director.
• The active waypoint must be displayed in the pilot’s primary field of view…

2.13.1 RNP 1.0 RF Leg Types
AC 90-105 states that procedures with RF legs must be flown using either a flight director or coupled to the autopilot.

This STC has demonstrated acceptable crew workload and Flight Technical Error for hand flown procedures with RF legs when the GTN installation complies with limitation set forth in Section 2.12 of this document. It is recommended to couple the autopilot for RF procedures, if available, but it is not required to do so. See section 4.5 of this manual to determine if this capability is supported in this installation.

At present, only a few non-AR approaches with RF legs meet the criteria in the STC and AC 90-105A. But RF legs could become more common on “standard” procedures to provide paths that offer better noise abatement, reduce airspace conflicts, and improve ATC efficiency, and pilots flying with GTN avionics (or similar navigators offered by other manufacturers) will be able to fly those procedures.

Changes to Flight Plans with Procedures in GTN System Software 6.x

Garmin has released updated system software (version 6.11) for the GTN series of navigators. The software includes several new features. One of the most important changes, at least for day-to-day operations for typical general aviation pilots, is how loading (or activating procedures) affects departure and destination airports in flight plans (routes).

To learn about and practice using the new features, download the latest version of the free GTN 750 PC Trainer Lite from Garmin. The download includes updated manuals (PDFs) for the GTN series avionics that describe the new features in version 6.x.

I have experimented with how the new system software in the free GTN 750 PC Trainer Lite available from Garmin, and the following examples illustrate the changes and offer suggestions to help you adapt your personal techniques for using a GTN-series navigator in the cockpit. In particular, I offer suggestions for displaying information about your destination airport (frequencies, current weather, and so forth).

To learn about the new ad-hoc hold feature in the updated software, see Flying Ad-Hoc Holds with a GTN 750 here at my blog.

Basics of the Change

First, here’s a note in the updated Pilot’s Guide for the GTN 750 that describes how software version 6.x changes flight plans (routes) when you load an approach (or, it turns out, a departure procedure).

Now let’s look at how this change affects when and how you load and fly a typical instrument approach.

A Typical IFR Flight Plan

Suppose you plan to fly from Boeing Field (KBFI) in Seattle, WA to Spokane International Airport (KGEG) in eastern Washington. Here’s a route across the Cascades that I often fly in my normally aspirated Beechcraft A36.

Note that the first and last waypoints in the flight plan are the departure airport (KBFI) and destination (KGEG). ATC typically assigns a SID when departing Boeing Field. When runway 13R is in use for IFR departures, your clearance includes the KENT7 (or the current version) SID, which you load as follows.

Note that after you load the departure, KBFI no longer appears as a waypoint in your current flight plan. The first waypoint in the flight plan is now the runway ((RW13R), which is the first fix in the KENT7 SID. The IDs of the departure and destination airports, however, remain in the title of the Active Flight Plan.

Here’s the first tip. If you use your GTN navigator to retrieve frequencies and other information about your departure airport, collect that data before you load a departure procedure.

Now assume that you have departed KBFI, followed the SID and ATC vectors to join V2, and proceeded to a point west of Spokane where you are preparing for the arrival and approach at KGEG, say the RNAV (GPS) RWY 21 Y approach.

Given that you’re approaching KGEG from the west, ZOOMR is good fix to choose, at least initially, as the transition for the approach. ATC will probably provide vectors, but with all the fixes from the west now in the flight plan, it’s easy to accept a clearance direct to any of the fixes or legs along the path to the final approach segment.

Notice that after you load the approach, the GTN removes KGEG from your active flight plan—unless the active leg of your flight plan includes the airport. Versions of the system software prior to 6.x always added the approach name and fixes for an approach below the destination airport.

A Logical Change?

The change in behavior in version 6.x may disrupt your habits at first. But it also may reduce the potential for errors when you load and fly an approach (or DP) under typical circumstances.

The new behavior provides a seamless transition from waypoints in en route section of your flight plan to fixes in an approach. You no longer have to scroll below the destination airport in the active flight plan list to select an initial fix or to activate a leg of the approach you’ve loaded into the GTN.

A Change in Tactics?

The new behavior described above may lead you to change your basic technique for loading an approach.

I have long advocated loading procedures as early as possible—even before taking off if the destination is nearby—to reduce your workload during busy phases of flight. The new behavior in GTN software version 6.x, however, suggests a change in tactics, at least under some circumstances.

If you can determine well in advance which approach you prefer to fly—in-cockpit weather can give you an early alert about which runway is likely to be in use long before you can receive the ATIS or AWOS (that is, the one-minute weather at a non-towered airport)—then loading the approach you prefer or reasonably expect to fly is still a good idea. Just take a moment before you load the procedure to retrieve and note frequencies and other details about your destination airport from the GTN.

Pilots arriving or departing an uncontrolled airport that has automated weather broadcast capability (ASOS/AWSS/AWOS) should monitor the broadcast frequency, advise the controller that they have the “one−minute weather” and state intentions prior to operating within the Class B, Class C, Class D, or Class E surface areas. (AIM 4-4-6)

ONE-MINUTE WEATHER− The most recent one minute updated weather broadcast received by a pilot from an uncontrolled airport ASOS/AWSS/AWOS. (P/C Glossary)

If you prefer to wait until you are closer to the airport, or if ATC clears you direct to the airport or issues vectors before initiating an approach clearance, you can delay loading the approach.

If you wait until the active leg of your flight plan includes the destination airport, the GTN adds the approach below the destination airport, just as it did prior to version 6.x.

Or, as shown below, you can load a procedure early and then add the destination airport to the bottom of your current flight plan, so that the airport is still available as a reference and to provide easy access to the information about the airport in the GTN’s database. Here I’ve added KGEG below GANGS, the MAHP for the RNAV (GPS) RWY 21 Y approach. It’s easy, as before version 6.x, to touch the airport ID and then select Waypoint Info.

Add an Alternate?

The change in version 6.x also simplifies adding an alternate to your flight plan.

Suppose the weather at KGEG is close to minimums as you begin your arrival. Adding an alternate airport to your flight plan before you miss the approach could reduce your workload during a critical phase of flight.

Here I’ve added Walla Walla, (KALW) as my alternate after the MAHP at GANGS.

Now I can quickly retrieve information about KALW and even load an approach as soon as I get a new clearance from ATC.

This technique would also be handy during training flights, when you fly several approaches, either to the same airport or close-by fields.

Other Methods for Retrieving Airport Information

If you prefer not to fuss with the way version 6.x handles airports in flight plans that include procedures, you can still retrieve information about airports from the GTN’s database, even if your departure and destination airports are no longer in your active flight plan.

For example, touch the map, scroll to display an airport, and touch an airport symbol. Touch Waypoint Info to display details (frequencies, current weather, runways, NOTAMs, and so forth) about the airport.

You can also use the Nearest Airport feature (available from the Home screen) to gain quick access to details about your destination—provided you’re not too far away.

Or you can use the various search option in the GTN to find an airport and retrieve information about it.

More to Come

I’ll have more to say about the updated system software after I’ve had it installed in my airplane and explored the new features on test flights. Stay tuned.

Flying Instrument Approaches without Activating the Approach

Many pilots who use sophisticated GPS-based navigators have difficulty consistently loading and flying approaches. As I’ve noted elsewhere, pilots who use the vectors-to-final option may find themselves scrambling to comply with a clearance that directs them to a specific fix in the approach. Other pilots fumble with activating an approach, a process that sometimes leads the airplane in an unexpected direction.

AIM 5−4−6. Approach Clearance

6. …RNAV aircraft may be issued a clearance direct to the IAF/IF at intercept angles not greater than 90 degrees for both conventional and RNAV instrument approaches. Controllers may issue a heading or a course direct to a fix between the IF and FAF at intercept angles not greater than 30 degrees for both conventional and RNAV instrument approaches.

Many instructors, myself included, have long advocated using the flight plan page on your navigator to simplify flying instrument approaches (and SIDs and STARs). In fact, the flight plan page or menu is typically the most misunderstood and least-utilized feature of most GPS navigators.

I’ve created a short presentation that guides you through the process of loading (and “activating”) an approach on the Garmin GTN 750. The presentation, Flying an Approach with the GTN 750, is available as a free PDF that you can download from the Aviation Documents folder at my OneDrive page. You can find many more useful, free references there.

The basic technique and principles described in the presentation apply to most IFR-approved GPS navigators, but you should, of course, review the handbook and AFM supplement applicable to the unit in the aircraft that you fly.

After reviewing the presentation, practice with the free simulators available from Garmin and fly with an instructor or safety pilot in VMC before you launch on an actual IFR flight.