by Jeff Van West
Ah, the joys of a new airplane: the custom N-number, the smell of a fresh leather interior, the sunlight glinting off the LCD displays. If youre buying new, youre likely also buying a primary flight display system or PFD, along with a companion multi-function display or MFD. The two popular systems are Avidynes Entegra and the G1000 by Garmin. A third, Cheltons FlightLogic, isnt available for any new fixed-wing aircraft but can be retrofitted.
Only the Columbia Aircraft Manufacturing Co.-formerly Lancair-offers the choice of systems. The rest of the airframers have shacked up with one or the other and, if you want the airplane, you have no choice on the glass panel.You take what they certified in the airplane.
Since this is the part of the airplane youll look at more than any other and differences between the systems-coupled with your personal preferences-might sway which airplane you choose to buy, we decided to compare the two principle systems toe to toe. Our research revealed that the two products are different enough to nearly amount to an apples-to-oranges comparison. But in the end, you still have to make a choice, either based on the airplane or the glass system itself.
The key determinant, in our view, is operability and learnability. Another way of phrasing that is how much brainpower does it take to make the system play at a basic level? Or any level? And how much practice does it take to confidently hit the high notes?
Where Glass Excels
Once you get over the gee-whiz factor, flying glass means substituting the skill of reading a round analog instrument for a linear one. Some things, such as maintaining 8000 feet, might be easier when glancing at a steam gauge than a tape. But others-flying Vy at precisely 101 knots-are more fun with glass, even if they dont deliver much take-home value to the GA pilot. A glass panel does, however, deliver at least four major benefits that you cant get by combining a six-pack with a GPS 396 on the yoke.
The full-screen artificial horizon is a huge plus. Its so big that its almost always somewhere in your peripheral vision. More important, though, is that you see it behind other instruments. When you scan airspeed or altitude or adjust the HSI, the horizon is there in the background and youll immediately notice if its not where it should be. The days of allowing your altitude to deviate as you change the heading bug are gone.
The arrangement of PFD information creates concentric visual scans. The most important information-attitude-is in the center of the scan. The next level of information- airspeed, altitude and heading-are placed equally around the attitude in a ring. Less critical information, such as vertical speed and rate of turn, are a bit further from the center with useful information such as power settings, waypoint information, true airspeeds and the like even further on the periphery. If you drive the aircraft into an unusual attitude on either platform, chevrons point back to the horizon. Garmins G1000 goes a step further: It removes all the extraneous information from the display so the only thing to look at are the critical items you need to fix the excursion immediately.
The exchange of information (called integration) within the PFD/MFD/GPS system means you can enter information in one place and let it cross-flow to several others. This means change your flightplan in one place and it updates everywhere else-waypoints on the PFD change, fuel calculations change, weather is presented for new waypoints and so on. Information cross-flow also allows for instantaneous true airspeed and wind calculations. For some OEMs, the Entegra system elevates this to the point that the correct Vy for climbout based on the current altitude and temperature is calculated.
Finally, only an integrated glass panel gives truly flyable trend information. Youve always had rate of turn, but now you can see where the airspeed, altitude and position of the airplane will be six seconds into the future. Once you become accustomed to interpreting the data, you can join any track or level off at an altitude with ghostly smoothness.
Theres lots of other stuff you can layer onto the displays, such as NEXRAD weather or terrain warnings, but all thats available with a full-featured portable GPS or electronic flight bag, with several fewer zeros on the price tag.
Avidyne and Garmin have pursued radically different basic philosophies in designing their respective glass systems. Avidyne builds everything into the boxes you see in the panel, including the solid-state ADAHRS gyro package that tells the system which way is up. (It does have some external sensors for traffic and weather.) Garmin, on the other hand, adopted a modular approach, with the screens driven by an array of external sensors and boxes called LRUs or line replaceable units. These can be installed anywhere in the airplane-sometimes behind the panel, sometimes in an avionics bay, or both.
How much information the system can handle is more a function of hardware than software. The G1000 has the clear edge due to its modular design. The display is just a display and graphics processor, with the actual computing done by a faceless box mounted elsewhere. The LRUs are laced together by a network similar to an office computer network. Not enough processing horsepower for the latest avionics? Upgrade the processor. Want to add a function? Add a new module to the network.
The Entegras all-in-one construction is more limiting in terms of upgradeability. While airplanes wont ever see the upgrade cycle of office computers, this is still a worthy concern. Avidyne concedes that the Entegra system on most new airplanes is running at over 50 percent of its capacity.
The difference in the ADAHRS/AHRS gyros are worth noting. The Avidyne system takes several minutes to start up and the aircraft must remain stationary for part of that time. The Garmin system is ready in less than a minute and you can be moving while it finds itself. This is more of an issue if you have to restart the system in the air-a very rare event-than for day-to-day ops. The Avidyne system can air start if you can keep wings level and coordinated long enough, but any bump will disrupt the process. We got the G1000 to air start in less than two minutes, with 30-degree banks left and right. A truly rare failure would be of one of the PFD displays themselves, but if it were to happen on a G1000, the MFD can revert to show the primary instrument functions on the right side, something the Entegra cant do. So if you lose the Entegras PFD, youre flying the steam gauges – with a huge moving map to help.
Both systems can back and fill with software updates, but its up to the aircraft manufacturer how – or if – these updates will be delivered. For example, Garmin built the G1000 with 3-D graphics capability, but that doesnt mean youll get synthetic terrain in your Columbia 400 someday.
Avidyne just completed a software upgrade and worked with OEMs to notify all Entegra owners. The displays had to be sent back to Avidyne for the upgrade, since it included replacing some logic boards and cable connectors, for $495. Owners could add flight director capability to the PFD for an additional $1000.
The fair comparison is between the combination of the Entegra displays and the Garmin GNS430s to the G1000 because the G1000 combines both PFD/MFD and navcomm functions. The G1000 display and buttonology appears cluttered compared to the Entegra, but theres a reason for this: It does a lot more.
An advantage of the G1000s combined approach is a less cluttered overall panel inside the airplane. The Entegra/GNS430 combo force you to reach around the airplane more often to push the right buttons, but it does give you two extra screens to play with. The G1000 answers that with its inset map and mini-flight- plan feature that creates a screen within a screen on the PFD.Score one for Garmin on reining in the ever-expanding tyranny of buttons and boxes in the cockpit. Its all in front of you, not on the pedestal.
While the two PFD systems have more in common than not, each one has a few gold-star features and minor annoyances worth noting.
Airspeed Indications – Both designs use an airspeed tape, with Garmin showing 30 knots on either side of your current airspeed and Avidyne showing 20 knots. In both, the indicated airspeed shows in white on black, the highest contrast and therefore easiest to read. Trends point six seconds into the future and both displays have bugs for V-speeds such as Vy or Vglide. On the G1000, these are set by the user and can be toggled on and off individually. On the Entegra, theyre pre-set or calculated and are either all on or all off.
Both displays show true airspeed, groundspeed and outside air temperature, but on the Entegra, these are grouped together in a single box. The relationship of these three elements gives you an intuitive feeling of the winds and weather aloft and can cue you that conditions arent what you expected. Garmin has scattered these about the display with TAS under the airspeed tape, OAT in the lower right and GS on the MFD. Score one for Avidyne here.
Avidyne also shows engine gauges, such as RPM, MP, torque or percent power, to the left of airspeed for several OEMs. This is an intuitive design as it puts the airspeed tape and attitude display in your view as you adjust power – handy on an instrument approach. The G1000 shows the engine instruments on the left side of the MFD.
Altitude/Vertical Speed – Both systems provide altitude tapes showing 300 feet either side of the current altitude. Both show vertical speed a bit farther to the right. The big differences here are in the bugs. The Entegra gives you both altitude and vertical speed bugs. These bugs drive the flight director, which, in turn, drive the autopilot. The G1000 offers an altitude bug but only offers a VSI reference bug in some installations. The bugs do drive the autopilot in the integrated GFC700, which is only flying on Raytheon aircraft for now. In Mooney, the altitude bug will also drive STEC autopilots.
The G1000 altitude bug is also only set to the nearest 100 feet, where the Entegra can set the bug to the nearest 10 feet. This is a big miss for Garmin, in our view. We fly to the nearest 10 feet on an approach and the bug-even if not connected to the autopilot-should reflect that.
HSI and Maps – Both systems give you HSI presentations in 360-degree or arc views with a heading bug, but they diverge widely from there. The Entegra HSI can display a map over the HSI. The G1000 offers a small inset map to the left of the HSI. Several electronic HSIs have this map-on-HSI function and many pilots like it. In our opinion though, its hard to learn to use well and is visually cluttered.
We see Garmins small inset map as a more intuitive and flexible solution. Its also configurable independently from the main MFD moving map so one can display simply the flightplan, traffic and terrain and close range while the other shows all topography and weather within 100 miles. Both PFDs can toggle their maps on and off.
The Entegra lists up to three independent waypoints to the left of the HSI. Each one can display name, course or bearing and distances, times or frequencies as appropriate. The top waypoint is always the next waypoint in the flight plan or active VHF beacon. The next two, however, can be any frequency or waypoint on either of the two GNS430s. This is a great feature.It can simultaneously show times and distances to both the IAF and the airport itself on approach. The second waypoint can be an RMI-like pointer on the HSI, as well.
The G1000 has a lone CDI button that cycles through the two nav radios and the next GPS waypoint, letting you navigate to one at a time. You can add RMI needles, but not pointing to two different GPS-derived waypoints. Again, we see this as an opportunity missed by Garmin to provide information the system could easily generate. The G1000s moving map to the left of the HSI and the ability to see the flightplan to the right of the HSI mitigate this limitation somewhat.
In our opinion, Avidyne wins two more points for clear thinking on the HSI area. Current winds aloft always appear just to the upper right of the HSI and the winds are given to the nearest degree. This makes anticipating wind corrections a snap. Garmin has recently added a wind vector near the HSI, but its only an arrow for direction and wind speed. The Entegra also displays a CDI beneath the attitude indicator ladder in addition to the CDI on the HSI, where the G1000 only shows lateral deviation on the HSI. In the final moments of an approach you can tighten your scan on the Entegra more than you can on the G1000.
Navcomm – The Entegra has no control over your VHF radios-you control them entirely from the GNS430s in a conventional way- so the G1000 stands alone here. The plus of Garmins design is that you can see both nav and both comm frequencies from either the PFD or the MFD. Nav frequencies automatically ident (most of the time) and the power output of the Garmin transmitters is a blazing 10 watts.
The downside is time learning how to use the G1000 radios. Each color or box has a meaning. The green frequency is active and selected. The white frequencies are either active but not selected or in standby to the active frequency with a tuning box around it. The grey frequency is standby for the inactive frequency. You must know this cold.
The nav frequencies break with tradition (and years of learned behavior for most of us) and put the active frequency to the right of the standby.This puts the active frequencies toward the center of your scan and the standby frequencies closest to the knobs that control them, but is confusing to the new user. Calling up frequencies from your flightplan usually puts them into the standby of the active frequency, but they can go directly to the active frequency for an ILS or VOR approach.
The G1000 PFD has several other integrated features including transponder control, timers, marker beacons and system alerts. With the Entegra, some of these functions are on the MFD and others, like the transponder, reside entirely on other units.
The heart of the MFD on either system is the moving map and, as with the PFD, their similarities outweigh their differences. Most of your study time will be learning where to find the information you want on either MFD. There are some key points, though, in each systems favor.
User-controlled fields – The Entegra wins big with a big datablock on the upper right of the main map page that you can make display virtually anything you want, although the factory defaults are pretty good. The G1000 lets you customize only four fields at the top of the MFD and the list of options in limited. There may be a customizable block in the future, according to Garmin.
Layered information – Using softkeys on the side of the Entegra or the bottom of the G1000, you can layer weather, topographic, traffic and airport data on the map. The G1000 goes a step further and can add terrain and obstacles to almost any map view. The obstacle display is very precise, too.That red tower on the display can be matched with that 1200-foot tower off the right wing.
The G1000 also has more computing horsepower to show all that stuff. Turn every display option on and the Entegra noticeably slows down on its refresh rate. We couldnt get the G1000 display to even hiccup, no matter what we chose to show.
Both systems let you layer XM Radio-based weather, but only Avidyne lets you see it all on the main map page, including graphic METARs. Garmin puts big-picture items such as NEXRAD on the main map page but has a separate weather page to display all the weather including the METARs.
The graphic METARs distinguish between five levels of VFR and IFR weather. To see the details on the Entegra, you can dial in the waypoint information or roll to the trip or nearest pages, which shows the METAR and TAF for each waypoint on your flightplan. You can get the G1000 to display weather for flightplan waypoints, too, but it requires some button-pushing.
The Joystick – The G1000 has a hidden weapon for weather -or any airport information-called the Joystick. Press the stick to get a pointer and then scroll around the map to select any feature. You can get information, weather, go direct-to, or just see bearing and distance almost as easily as if it were a touch-sensitive screen. The G1000 is now available from some manufactures with FMS-style keyboard controls. This level of user interface is long overdue and only the G1000 offers it.
Engine displays – The G1000 permanently displays engine info on the left side of the MFD. The display is simple and easy to read. Softkeys let you see some details and access multi-probe EGTs for leaning. The Entegra has a dedicated page for the engine information with flashy graphics and a separate page just to set the amount of fuel on board.
While that may be excessive, the Entegra calculates percent power, which is very useful, and has a lean assist function that walks you through either best economy or best power leaning with precision, although we have had reports that the power calculations are sometimes incorrect on the Avidyne system. The Entegras normalize function makes keeping track of EGT deviations a no-brainer.
Trip/Flightplan – Because the G1000 is an integrated system, you can view and edit the flightplan directly on the MFD or PFD. You also have a huge area to display information and options for the flightplan. Garmin doesnt take advantage of all that real estate as much as it could right now. It may with software revisions. The Entegra wont let you edit a flightplan on the MFD or PFD like the G1000, but its trip page does an excellent job of displaying key information on your route-including METARs and TAFs.
Repair/Durability – As glass panels age, this could become a sticking point. Thus far, glass panels have been relatively reliable. But owners worry they could be expensive to repair when they reach middle age.Avidynes solution is a long-term service contract that covers everything for $1600 a year. Whatever breaks, they fix. If you dont opt for the service contract, repairs are on a piecemeal basis and could be expensive.
Garmin will use a flat-rate repair for each LRU, with costs based on actual warranty repair data. So far, those flat fees havent been announced.Conclusion
Comparing the Entegra and the G1000, were reminded of the dichotomy between Macintosh and Windows computers. Users of each system extol their virtues, but both get the job done with varying perks and drawbacks.
We dont think either system is a wrong choice, theyre just different.Both are close in performance. The G1000 is the more powerful, more capable system and looking forward, it probably offers the most growth potential, if thats important to you.
But in our view, a glass cockpit is all about real-time, everyday operability, not a miles-deep featureset that you may never use. In that regard, when it comes to flying from here to there under the guidance of glass, the Entegra is simply easier to use. This is partly due to sharing the navcomm load with the GNS430s and partly due to more time in the field resulting in more mature software. But if youre flying a piston single after a long day at your real job, that simplicity can make a world of difference in comfort and confidence.
Are we saying the glass panel should shape the airplane buying decision?Yes, but only in the same way that payload, range or any other factor weigh into your choice. Only Columbia lets you choose between an Entegra or G1000 but worth noting is that each manufacturer implements the system a bit differently. The G1000 in a Diamond is not exactly the same as a G1000 in a Cessna.
The best plan is to fly each one more than once, so you can see what you like, have some time to think of questions or issues, and then fly it again.There are now enough rentals with either system to make this practical. Make sure you like-or can at least live with-the system in the aircraft you want to own. Know that when you buy either system, you are signing up for a significant training load, more so with the Garmin than the Avidyne. And youll be looking at those pretty pictures a lot more than youll look at the paint scheme.
-Jeff Van West is a CFII and editor of IFR magazine. Hes also a freelance writer in various computer technologies.