Is there a cost effective alternative to the Garmin 750?

Is there a cost effective alternative to the Garmin 750?

For years, there were only two choices for a retrofit multi-function GPS navigator—either Garmin’s GNS430 or GNS530—or the current GTN650 and GTN750. Bendix King offered the KLN94 standalone GPS, but it wasn’t an all-in-one WAAS navigator with an open architecture. It also lacked a comm and nav radio and it didn’t have any multi function capability.

These are all the features the KSN770 was supposed to have when it was announced several years ago. It’s no secret that the KSN770 stalled in the R&D phase and essentially became obsolete before it was even brought to market. But a partnership between Bendix King and Aspen Avionics ultimately advanced the product to the certification stage.

Hybrid Control

Bendix King believes that many pilots aren’t entirely sold on a total touchscreen interface, so they designed the KSN770 with a combination of touchscreen and hard buttons and knobs. This hybrid interface arguably brings the best of both worlds, especially for pilots that prefer to interface with the unit the old fashioned way.

“You can interface with the unit using knobs, touchscreen, onscreen keyboard control, or with the joystick. Old grey-beards may still prefer to transfer the radio frequencies from standby to active using a familiar transfer key, so we added it to the KSN770 bezel,” said Bendix King chief test pilot Doug Hawley during our recent demo flight.

Tuning the radio frequencies on the KSN770 can be accomplished with an onscreen touch keypad but you can still twist, turn and tune the radios with a familiar concentric knob and adjust the volume with a familiar round volume control. The comm radio frequency window is strategically positioned in the lower left corner of the display, in close vicinity to the tuning knob and frequency transfer button. The nav radio—including glideslope receiver—is tuned in similar fashion and has a dedicated frequency window in the upper left portion of the screen.

Since the user interface was
mostly designed by Aspen Avionics, users of the Aspen Evolution PFD and MFD products will recognize the color and format of the KSN770s onscreen hot keys. There’s also an eight-position joystick—another way of entering data and manipulating the map screens. This joystick also serves as a cursor control device (CCD). The CCD trickles down from jet FMS systems, including the Honeywell Apex integrated avionics suite that’s in the Pilatus PC12NG turboprop.

You could also enter data in a QWERTY pop-up window. The screen is resistive, which means putting pressure on the surface with your finger or an object commands a given function on the screen. Bendix King says the touchscreen will easily work with gloves. What you can’t do is pinch zoom with two fingers as you would on a tablet display. Instead, the joystick is used for map panning and dedicated map zoom soft keys are placed on the left side of the bezel.

The 5.7-inch active matrix LCD screen is full VGA and has a 640 by 480 pixel count. The unit stands 5.25 inches tall, which is slightly larger than Garmin’s old GNS530. If you’re moving up from a GNS530, we will need to restack the avionics rack. Still, it shouldn’t require nearly as much work as fitting a Garmin GTN750. It requires a full 6.0 inches of vertical height.

The onscreen hot keys carry over from Aspen’s Evolution flight displays. They sit along the right side of the screen and are aligned with and displayed adjacent to their corresponding soft key. As an example, when configuring the map, hot keys and the corresponding soft keys are used to turn on and off various information overlays for each map. The best way to grasp the concept is to understand that hot means active, so the hot keys activate a function and turn green to indicate that the function is active.

VFR, IFR or Both

“The KSN770 was designed to give both VFR and IFR pilots tremendous amounts of information. You can customize the displays for the way you think and display as little or as much information as you want at one time,” said Hawley.
You can configure it for single-screen or split-screen view, add a single thumbnail view of traffic, for example, or two thumbnails for displaying both traffic and terrain, while also displaying the map page as a third screen.
The map can be configured for VFR or IFR (low or high airways) while traffic, terrain and weather—including XM data from Aspen’s EWR50 datalink receiver can be overlaid on each. The system is also compatible with the L-3 WX500 Stormscope. Georeferenced NACO charts—including taxi diagrams—come standard and are provided by Seattle Avionics. Navigation data is loaded through a USB port on the front bezel and the data is purchased through Honeywell’s WingMan Services data subscription division, via download.

The system can display a variety of TCAS, TAS and TIS systems, including Garmin’s GTX330/33 and Avidyne TAS. Traffic is displayed on a dedicated traffic page, in a thumbnail, and as a pop-up during traffic alert conditions.

Standard is an advisory terrain function with typical terrain coloring that’s displayed on the map page or on a dedicated terrain screen. The system also interfaces with the Bendix King KGP560 EGPWS.

Real-Deal FMS

At the core of the KSN770 is Honeywell’s WAAS-enabled GPS and FMS (flight management system). VFR pilots will find that single-point navigation is simple, especially with the Direct key on the bezel. Here you can select airports and navaids using the onscreen QWERTY keypad or by scrolling with the joystick. Point to point navigation is about as simple as it gets, in our view.

On the other hand, IFR pilots who aren’t familiar with operating a FMS will have a lot to learn when it comes to building flight plans and loading procedures. That’s because the KSN770 is a true FMS and you can create and load an entire flight from departure to approach before you even leave the ground. Users that are familiar with the KLN94 GPS (and Garmin’s GNS and GTN navigators) will recognize the Procedure hot key. It brings up a menu for loading departure, arrival and approach procedures.

There’s also an onscreen FMS function that’s referred to as “graphical flight planning”. The flight plan window has a dragbar that you slide with a finger to view the way points in the flight plan (or you can use the joystick). As you scroll though the flight plan, the flight plan way points are identified on the map screen, so you can watch the construction of the route.

Open Architecture

Impressive is the KSN770s ability to interface with a variety of remote systems, including new and older navigation displays. For instance, not all aircraft will be equipped with an integrated PFD, but the system is compatible with some traditional analog CDI displays, including the Bendix King KI209A and KCS55A HSI system. It also interfaces with many existing analog and digital autopilot systems—providing GPS roll steering and full nav tracking capability. The KSN770 is fully compatible with the Aspen Evolution PFD and MFD and with the Bendix King  KI825 electronic HSI.  

The system will also interface with the Honeywell RDR2000/2100 and RDS84-series weather radar. The weather data can overlay on the active flight plan and display on a dedicated weather radar screen.

The unit does display ADS-B data to include Aspen’s ADS-B receivers. The KSN770s WAAS GPS is an appropriate source for ADS-B Out and can feed the KT74 1090ES transponder.

Back in the Game
The KSN770 came to market on the heels of two other newer products from Bendix King: the KT74 Mode S ADS-B transponder and the KMA30 audio control panel (a product that’s made by PS Engineering but wears a Bendix King faceplate).

With a list price of $14,141, the KSN770 may not attract the lower end of the market that’s been waiting for the low-cost alternative products that Bendix King initially promised. It is however a powerful FMS that can hold its own against the Garmin 750 that is 30% cheaper and plays well with other legacy components in your aircraft without costly patch units.

“The KSN770 is the first of many products that Bendix King is developing as we move toward the future. It’s the cornerstone of the diverse product line we plan to build going forward,” said Roger Dykmann, Bendix King’s director of  product development.

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