IFD540 Flight Trial: Data-Rich, Configurable

Avidynes IFD540 navigator offers sizable utility and an easy installation. Its powerful for complex IFR missions, but questionable for basic ones.Enroute, Data Blocks, TerrainLearning, subscription, conclusion

After long certification delays, Avidyne is now shipping its IFD540 navigator, a unit billed as a while-you-wait slide-in replacement for Garmins GNS530W. Since Garmin has not offered a slide-in version of its flagship GTN750 navigator, the 540 is appealing to buyers looking for better flight planning capability, improved graphics and a hybrid touchscreen display, all without having to deal with a time-consuming and pricey installation.


With a list price just shy of $17,000, the 540 is a sizable investment that has many readers asking if the unit offers enough real-world functionality to ditch a functional and reliable GNS530W. Further, how tough is the learning curve, especially for those not intimately familiar with a GNS530?

In this article, Ill attempt to answer this, based on months of flying with the IFD540 during a variety of IFR and VFR missions. We covered the IFD540 feature set in previous articles, so Ill jump right into advanced system operation here.

Flight Planning
After flying with the unit in Northeast airspace, in addition to flights up and down the East Coast, I think the sizable gains in IFR flight planning capability is the best thing about the upgrade.

Much of that is the result of Avidynes GeoFill function, plus the onscreen touch keyboard that trickles down from Avidynes R9 integrated avionics suite. I think an option for a dedicated keyboard controller could kick the interface up a notch, as it does on a real R9, but that would require more effort.

GeoFill finishes the data entry automatically, filling the flight plan with fixes near the previous one. No longer is it necessary to consult a chart or tablet to enter all waypoints on an airway, as the Avidyne allows picking an airway and exit point from a list. For long airways like V1 on the East Coast, this can be an enormous time saver.

Viewing the route on the map during entry is convenient, and it can be displayed in a compact form on the right side of the display, while the map occupies the middle. Its even possible to drag the route line to add waypoints by rubberbanding, which will pop up a display of nearby fixes to add to the route.

Flight plans can be saved with descriptive names, reversed and activated. This feature is handy for saving a route component that is frequently used, such as a common departure sequence or as we expected when coming into the busy New York City area and expected routing around Washington, DC, and Philadelphia. Unfortunately, previously entered crossing altitudes are not saved with the routes.

Arrival and departure procedures can be added to the flight plan, including published crossing altitudes, although vector departures arent included in the database. Entering altitude restrictions elsewhere in the route is simple. Better, the Avidyne will display a vertical speed requirement to meet the restriction and a top-of-descent marker on the map.

Adding an approach is essentially identical to the GNS530W, by first using a hard PROC button, and then selecting the approach and transition. The Avidyne helpfully displays the type of GPS approach available (LPV or LNAV, for example), and a second touch of the PROC button displays available arrivals.

When selecting an approach and a transition, the map displays an onscreen preview, making it easy to choose correctly. Unlike the Garmin, however, the procedure is not immediately integrated into the flight plan. It must be manually activated by tapping an approach waypoint, then direct or activating that leg by softkey. One alternative is to edit the flight plan to remove the gap inserted before the transition waypoint.

When flying the approach, having upcoming waypoints, FAF, MAP and crossing altitudes on the right side of the screen (and the map in the middle) is fantastic for situational awareness. The next crossing altitude is displayed on the map, and Avidyne says all crossing altitudes will be displayed on the map in a future software release.

Approaches with holds are simpler to fly than with the Garmin; if cleared for a straight-in approach, a hold can be removed by softkey, and an on-screen alert and the softkey label clearly informs whether the IFD540 will sequence past a hold or continue it. The softkeys are labeled opposite from what the navigator will do. Continue Hold is displayed as a softkey choice when the navigator will exit a hold, as pressing the button will cause the navigator to, yes, continue the hold. This can also be discerned as the next flight plan leg appears in striped purple and white labeling on the map.

Prior to entering a hold, an alert displays the type of entry the navigator has selected. Inside the FAF, the Avidyne has simplified the pilots workload. After passing the clearly labeled FAF, a softkey becomes Enabled Missed. This can be pressed at any point to sequence the navigator to the missed approach.

After the MAP, the button becomes Activate Missed. Flying the missed, the appropriate altitudes are displayed directly in the plan, but is otherwise similar to the GNS530.

One quibble is you must remember to use FMS mode during the approach, as the approach-related soft-keys will not appear in MAP mode.

Altogether, learning the enhanced flight planning was straightforward as it is similar, but improved from the GNS530W. I think FMS programming is easier with touchscreen, rather than twisting dials, but the IFD540 does both.

In even modest turbulence, I prefer dials. Only a few features are accessible with touchscreen only, such as pan and zoom. For some things, like tuning frequencies, dials might be the better option.
The 540 has inactive Bluetooth and Wi-Fi thats being saved for future connections. Could a keyboard be one of them?


While Avidyne just revealed its MLB100 ADS-B receiver, it vows to maintain an open architecture for liberal cross-brand ADS-B compatibility, in addition to cockpit app functionality.

Using the IFD540 in flight can be similar to using the GNS530W. Many ingrained habits are identical, easing the transition. The familiar Direct, Enter, Enter key pattern still works as expected, and adding a procedure is the same, although activating it is a little different by pressing a dedicated softkey.

A welcome addition is the ability to add enroute holds with full detail about the direction of turns, leg time/length and course, which will be flown by the autopilot if equipped with GPS steering. Each waypoint in the route will show an ETE, ETA, distance and course, plus the amount of fuel remaining at that point-a feature we particularly liked when flying a long route at maximum fuel range during our evaluation flight from Florida to New England.

Handling reroutes is especially simple, as the route can often be entered directly from the clearance. One real-world challenge I experienced was dealing with a reroute that included a leg to fly a certain heading to intercept a specified radial, and proceed inbound to a VOR. Fortunately, just entering the specified VOR directly into the flight plan produced a course only one degree off the clearance, but I could not determine how to enter a route component to intercept a radial into the flight plan if it didnt happen to work out conveniently like this did.

When flying from South Carolina to Connecticut after a diversion, we were rerouted south of Atlantic City out over the ocean to the Eastern end of Long Island before turning north. That route had well over a dozen waypoints, but entering it using Victor airways was trivial.

Determining a descent point into an airport is especially easy, as entering a crossing altitude on an airport waypoint pre-fills it with five nm out and 1000 feet above airport elevation cues. The descent point will then be displayed on the map and a doorbell-like chime will sound when its time to descend. The navigator doesnt take into account speed changes during a descent, so I configured it to use a lower descent rate than what would actually be flown and it worked out well.

Detailed information about the destination (or any waypoint) is available on a FMS tab, including runway diagrams, weather, procedures with graphical previews and even sector radials for multiple frequencies. Charts are easily accessed by touching an icon on the waypoint in the flight plan.
One advantage the IFD540 has over the GNS530W is the quality of its moving map, although as noted in the above sidebar, I dont think its graphics design makes efficient use of the available screen real estate.

There are two separate declutter modes for the base map and navigational map. A large number of weather overlays can be individually selected, including satellite radar, wind, METARs, METs and lightning (both datalink and sferics). Tapping on an airport will bring up a box with field information and decoded weather. It would be nice if tapping the DIRECT button while an information box was displayed would pre-populate that as the destination location, but it doesnt. Tapping on airspace boundaries will show name and altitude restrictions. The map display does not show altitude information, so tapping is required to discern avoidance when flying.

Zooming and panning by pinching and swiping should be intuitive for tablet users. Zoom out far enough and range rings will be displayed, showing current 45-minute reserve flight range and absolute range, but these rings dont compensate for changes in wind or course.

Data Blocks, Terrain
A huge amount of information is displayed around the map borders and is entirely configurable. Between the left and right sides and the top of the screen, there are over a dozen places for displaying user-chosen data blocks from a list of dozens of options. Especially comforting is having the minimum safe altitude, fuel time remaining and, for passengers, destination ETA that is constantly visible on screen.

The configuration process is a little clunky, in my view, but after playing with it for several hours it is satisfying to have the navigator set perfectly to taste. The downside is the amount of data that must be absorbed. If you are easily overwhelmed with screen clutter, youll likely leave these data blocks off, which really isnt using the IFD540 to its potential.

Another enhancement is a dedicated FREQ button for finding frequencies. The destination airport is on one tab and nearby enroute frequencies on another. All previously tuned frequencies are on a third tab, making it easy to fix a botched frequency entry. Even better, the IFD540 decodes entered comm frequencies and displays the assigned agency in the frequency box, so forgetting which approach frequency you are using is over.

The Avidyne provides forward-looking terrain advisories. These visual aural alerts will provide two levels of warnings if the unit predicts an intersection with terrain or obstacles within the next minute. The moving map displays yellow and red overlays where the terrain is under 1000 or 100 feet beneath respectively, and will enlarge any nearby obstacle threat icons.

This can be useful in unfamiliar areas or with rough terrain, but in congested areas, especially in the crowded New Yorks Hudson River corridor, it was distracting. Worse, the large obstacle icons rendered the map hopelessly cluttered. Additionally, I experienced a disconcerting terrain alert while at a correct altitude on a non-precision GPS approach in mountainous Vermont.

Learning, subscription
This, and nav data costs, are the most concerning to buyers. Updating the internal nav data is by USB flash drive and with the same Jeppesen software as the GNS530W. Insert the drive in the unit before startup, updates are selected and the navigator copies the data. This takes around seven minutes for the Eastern U.S., twice that for the full U.S. and can take over 20 minutes for worldwide data. It can only be updated on the ground and the navigator becomes unusable.

This makes programming a chore compared to the GNS530W, which can be programmed by swapping a new card for the old one. The IFD540 can also download log data back to the flash drive. The USB port can be used to charge devices, providing a full 2.1 amps of current.

Avidyne said it negotiated a package price with Jeppesen for the IFD540 data to includes full U.S. nav data, Jeppesen charts and airport diagrams/obstacles for $994 per year. This also includes nav data and Jeppesen charts for any other Avidyne displays in the aircraft.


As for transitioning to the IFD540, we can say with certainty that the IFD540 is a different beast than the GNS530W. Although it does everything the Garmin does, and retains a few ingrained flows, it changes and, we believe, refines the operations to simplify things and reduce pilot workload. That said, there is a lot to learn to get the most out of it.

Avidyne provides a free iPad app (and a Windows program), which simulates the IFD540 functions. I think the users guide is well written and the app is a good way to become familiar with the operating logic.

For users coming from the Garmin GNS530W (thats a huge chunk of the buyer base), I think the IFD540 can be overwhelming to those that havent mastered the Garmin-and based on our discussions with some users-there are plenty that still struggle with it. Still, except for navigating between pages, a user could enter an identical flight plan as with the GNS530W and the IFD540 would fly it the same. Direct to is identical, and procedures are loaded via PROC button in the same way.

The Garmins FPL button is analogous to the Avidynes FMS FPL tab functionality. It is really helpful that these basic features are so similar.

There are fewer hidden functions and items that have to be learned by rote with the IFD540 as well. Hard buttons such as Garmins OBS, which perform different functions in different contexts, have no equivalent with the Avidyne. The softkeys clearly show their function at all times and do change with context, which also provides information about what the navigator is thinking at any given moment. There is no equivalent to the MENU button, which does something different in every screen. Function tabs are always shown on screen and are easily accessed by touch and hard button. In our view, this offers a sizable advantage over Garmins GTN navigators. They have limited hard keys and major functions are mostly commanded by touch.

I spent roughly two hours with the Avidyne on the ground before flying, then about an hour flying with it in VFR. In all, five or six hours of familiarization was needed before being ready to fly the unit in actual IFR. On the other hand, Im a technophile computer geek, a best-case scenario. Someone who isnt comfortable with modern technology might require far more.

However, if the pilot is proficient with the advanced operations of the GNS530W, learning the IFD540 should not present a problem-and indeed may come as a welcome relief-since many tedious functions are streamlined. I think the IFD540 is a major improvement over the GNS530W in essentially every respect.

The GNS530 has been a staple for over a decade, but hasnt changed significantly since the WAAS upgrade. Still, the IFD540s tactical value depends heavily on the mission. The approximate $10,000 investment, after a GNS530W resale, is not insignificant in the cost/benefit analysis. If cost is no factor, I think this is an obvious upgrade, but not without exploring other possible upgrades, including a Garmin GTN750. Compared to a GTN750 upgrade, though, installing the IFD540 is fast. Shops told us the GTN750 requires 20 to 30 hours of labor, plus additional time to mod the panel so it fits. On average, IFD540 upgrades are taking a few hours, and might require minor, billable components.

If you fly a reasonable amount of IFR, we think the IFD540 can be a huge time saver and makes it much easier to fly approaches, and into and out of busy airports. For local VFR ops, the upgrade arguably has limited value.

I dont sense Avidynes intention of addressing my nits on the navigators inefficient map symbology, although feedback from other users could make a receptive Avidyne tweak the interface. In its current iteration, I think its features eclipse the aged GNS530. That, and its well-purposed IFR utility, makes the IFD540 a worthy investment.

Doug Fields is a regular Aviation Consumer contributor. He flies a Cessna 310R based in the New York City area.