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Garmin’s New Touch Screen FMS

GTN 650 and 750 replaces GNS 430/530, and does a lot more

By Mac McClellan, Editor-at-Large, EAA 747337
Garmin GTN 750
Larger view
The Garmin GTN 750 touch screen Flight Management System.

GTN 650
Larger view
The Garmin GTN 650 which will fit in the same panel space as the Garmin 430.

All photos courtesy of Garmin

March 24, 2011 — Garmin’s all-in-one nav and com GNS 430/530 GPS navigators have been the best-selling panel mounted avionics ever with more than 110,000 delivered since the 430 was introduced in 1998. But for the past several years Garmin engineers and pilots have been working to create even more capable and pilot-friendly systems that cost only a little more; the result is the new GTN 650/750, which was publicly unveiled late Wednesday. (March 23)

The headline feature of the new GTN family is touch screen operation, and that is certainly a first for certified panel mounted avionics, and is very easy to use. The other attention grabber is the GTN 750’s display size, which is double that of the 530. But for me, the most important features are operational because Garmin has added missing capabilities - particularly to the larger 750 - to make the new units complete flight management systems (FMS) including airways, audio control function, and transponder operation.

Garmin has more experience with touch screen electronics than any other avionics maker because of the millions of consumer GPS devices it has designed and built. Garmin had already announced touch screen control systems for its turbine level avionics systems, so we all knew where the company was headed. Despite its success, making touch screen GPS navigators for everyone from drivers to joggers to airplanes are different. Garmin has spent several years in the lab and in the air perfecting touch screen controls for the GTN series that work in the GA environment.

Touch screens and turbulence
Though Garmin had given me confidential briefings on the GTN development over the past few years and I got to operate prototypes I still wondered how well the touch screen mounted in a vertical instrument panel would work in actual flight. Back in the 1970s and early ’80s both King Radio and Collins went down in flames with keyboard avionics control systems that were mounted in vertical panels. It was just too hard to find and press the buttons in turbulence.

The FMS keyboards in turbine airplanes work fine because they are mounted horizontally in the pedestal between the seats, or on “tilt” panels that allow you to rest your palm on the bezel while pressing the keys with your fingers. But would the vertical mounting necessary in nearly all GA airplane panels work?

After flying the GTN 750 and 650 in Garmin’s Mooney Ovation I can emphatically tell you that my fears were totally unfounded. I found it not only easy but even natural to use the touch screens for all data entry and mode selections. Garmin has built in finger grips on the display bezel so you can use a thumb and finger to steady your hand, but I never felt the need to use them. Tapping the screen with my finger even in some turbulence was no problem. It took a few tries to figure out just how much pressure the screen responds to best, but by the time we landed after an hour or so of IFR flight I felt perfectly at home using the new systems.

Like smartphones and many other consumer touch screen electronics the GTN responds to moving your finger across the screen. If you want to pan the moving map, for example, simply slide your finger in the direction you want to go and the screen moves. You do the same for moving up or down in a menu. The operation is perfectly intuitive and enough finger movement is required so that the display doesn’t jump quickly but changes smoothly.

Press for success
The touch screen technology in the GTN is the pressure sensitive type rather than the capacitance type used in many consumer electronic smartphones and tablets. It takes a little firmer touch to operate the GTN compared to some touch screens you may be using, but I found that to be a good thing because there is less chance of getting a “double hit” or making some unintended entry.

A big reason the GTNs are so easy to use is the effective menu design. The menus are very short and on the 750 with its greater size, the item you want is almost always no more than a second press away. For example, to enter a new frequency simply tap the standby frequency at the top of the display and a big keypad appears. Touch the numbers of the new frequency - and the numbers are really big on the 750, so even fat fingers don’t miss - and one more tap sends the new frequency into the standby window. To transfer the frequency to active, all it takes is a touch of the frequency.
Even though the touch screen is easy to use the GTN series retained a twist knob that can be used to enter any and all data. If the bumps are too bad to use the touch screen you always have the knobs to hang on to.

820
Larger view
The GTN 650/750 offers graphical flight planning and the ability to program airways into flight plans.

At its heart the GTN series are WAAS-capable GPS navigators combined with com and VLOC radios in a single unit. The GTN 650 is the same exact size as the GNS 430 so it fits in panels with restricted space. The GTN 750 overall height is 6 inches compared to the 2.65 inches of the 650, so it does require considerably more panel space. However, the 750 can control a remotely mounted audio panel and transponder, so those boxes can move out of the instrument panel into any available space.

Actually, the part of the 750 that extends behind the panel is much smaller than the display, so the remote audio control and transponder can stack behind the display using no more panel space. The extra display size of the 750 allows it to be a full multi-function display (MFD) showing IFR charts, Garmin’s Safe Taxi airport diagram, XM Weather, traffic, and full-capability moving maps.

Graphical flight planning
Flight plan management on the GTN series is greatly simplified compared to the 430/530s. Instead of knob twisting to enter the identifier for an airport or fix along your route, you touch a keypad on the screen. The small size of the GTN 650 demands that you make two touches to call up the characters, but on the 750 a full alpha-numeric keypad appears.

You can also do graphical flight planning by touching fixes shown on the moving map. Or you can use your finger to “drag” a leg of the flight plan on the map over to a different fix and enter that into the flight plan by tapping the fix. This feature will be very useful in crowded airspace where re-routes are common. With the airways called up on the display you won’t need to hunt around on the chart to find the new routing you were just cleared to fly.

I think the most common use of the graphical flight planning capability will be when deviating around weather. You can simply drag your route on the display over to a point where you clear the weather shown on the display and tell the controller you want to go to that point. You can graphically move your route to any spot on the display, not just to published fixes, and you will see bearing and distance to that spot. So, you could then ask the controller to deviate left or right so many degrees for so many miles and know that you are flying to a spot that doesn’t show a Nexrad radar target.

For VFR pilots the graphical flight plan will be useful for flying around regulated airspace. When you see airspace ahead that you want to avoid you can use your finger to drag the route to a spot that keeps you clear. Then you can keep the autopilot in nav tracking mode and be sure that you miss the regulated airspace.

The airway option
One of the capabilities that pilots who fly in the crowded airspace along the coasts or near any major city wished for most is the ability to enter airways into the flight plan on a 430/530, and the new GTN family can now do that. You can tap any fix that you have in the flight plan and one of the options that appears is to enter an airway. With another screen tap you see all of the airways crossing that fix. Tap the airway you are cleared to fly and automatically a list of fixes along that airway appear and you tap the one where you want to exit the airway.

Airway entry has been a standard feature in FMS for turbines for many years but Garmin designed its system a little differently. On the FMS I am familiar with the VORs and intersections along an airway come up in their sequence along the route. On the GTN the fixes appear in alphabetical order instead of in their sequential location along the airway. The sequential ranking of fixes makes more sense to me, but maybe that’s only because I am used to it.

To see the GTN 750/650 in the real world Garmin’s Ben Kowalski and I filed an IFR flight plan along airways from my home base at Muskegon in Michigan over to Lansing. The weather was marginal VFR with a ceiling barely above the 1,000-foot minimum so we would be flying in actual conditions.

Knob-ology is not dead
Ben and I had talked about the new features of the GTN series over lunch, but in the airplane we decided that Ben would leave me to figure out how to operate the new systems. I have been flying with GNS 430/530 since early 1999 so I know those systems cold. If Garmin succeeded in retaining the best features of the 430/530, while adding more capability that is easier to use, I should need very little help to operate the GTN. And I can tell you that Garmin has succeeded. If you know how to use a 430/530 you will be up and running with a GTN in minutes.

Both a GTN 750 and 650 are installed in Garmin’s Mooney Ovation and it is the first non-test installation. The audio panel and transponder are remotely mounted so all you see in the radio stack is the 750/650 and the autopilot. Even with the huge 750 display there is lots of room left in the Mooney’s radio stack.

820.5
Larger view
The touch screen menu on the GTN 750.

There are two dedicated “hard” buttons, one to fly direct to a waypoint or airport just like in the 430/530 and the other to return to the main menu. On the main menu page are all of the functions you find in the 530/430 including the flight plan, procedures, activate the approach, and so on. The icons are exactly the same as Garmin is using in its turbine systems and they are intuitive. There is a “back” soft key on the lower left of the screen that is very useful to move in and out of menus, but I found that I used the menu hard key most often to call up the main menu.

A tap on any fix or airport brings up available information for that point so one tap on KMKG brought up the frequencies I needed to get going. A tap on the frequency moves it into the com window. With my 530 and 430 I do the same thing but I have to use the cursor to highlight the frequency and then push the enter button. I estimate the touch screen and shorter menus cut the time in half to enter the flight plan, call up the frequencies, and be ready to taxi.

I am sure the controllers thought we were a little weird for wanting to fly to the Muskegon VOR, then fly V-450 to GIBER to join V-26 to the Lansing VOR and then to the Lansing airport, but they didn’t say anything and cleared us as filed.

Hands off missed approach
Nearing Lansing I tapped the screen to select the ILS approach from the menu of procedures and the controllers cleared us for the option of flying the published miss to the hold over the VOR. The GTN 750 knew the missed approach procedure was to fly runway heading to 2,500 and then direct to the VOR so that is what appeared on the display.

GTN 650
Larger view
The GTN 650 in terrain display mode.

As I reached 2,500 on climb-out the course automatically changed directly to the VOR. Nearing the VOR the 750 announced that the published procedure is to make a teardrop entry into the hold and used a series of arrowheads on the moving map to unmistakably show where and what direction to turn. Of course, I let the autopilot handle all of that while I watched. Back at Muskegon I entered the LPV approach using the same actions as you would with a 430/530W system, but again, there are fewer steps to call up and activate the procedure and the screen tapping takes less time than the knob twisting.

Finding space in the panel
The list price for the GTN 750 is $16,995; the 650 is $11,495. Those list prices are higher than the list for the 430/530W but not a lot. The street price will undoubtedly be lower and Garmin has 650/750 units in inventory and ready to go. The FAA has granted full TSO approval and Garmin recently received the multi-model STC that covers just about all production airplanes.

If you have a GNS 430/530W you can replace it with a 650/750 without adding more wires or changing the antenna and cable. The GTNs use a different mounting rack and connector, and the 750 is substantially taller than the 530, so some mechanical work will be required to mount the new boxes, but overall, installation should be fairly simple. If you are upgrading from a 430/530 that is not WAAS-capable you will need to install the WAAS antenna and cable. Garmin plans to keep the 430/530 in production for as long as there is demand, but unless you are a fleet operator or for some other reason want to maintain commonality, I can’t imagine why you wouldn’t spend a few extra bucks on the GTN to get so much more capability.

The highest praise I can heap on the GTN 650/750 is that Garmin retained all of the best features of the amazingly successful 430/530, added even more capability, and still created an FMS that is easier and even intuitive to use. I know that if you get to touch one, you are going to want it.

 


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