Copyright © 2016  Grand Rapids Technologies, Inc.                      

Electronic Flight Instrumentation for Experimental Aircraft Since 1991

We routinely take in older units for upgrade or even trade-in toward new ones.


General Upgrade Information

How do I send in my unit?

  1. Download and fill out the service request form on the back of the Upgrades Price List with all of your contact information and specify what you’d like done.  You may fill in your credit card information.  We will call you for the final bill including the cost of return shipping.
  2. Back up your settings before removing your display unit. To do this, insert a memory stick into the USB port.  Turn on the system.  Go to Display Unit Maintenance and choose “Back Up Settings”.  This stores all the settings on the USB stick.  When you get your unit back, if the settings have been erased during the upgrade process, you can reload them off the stick.  This is a huge time and frustration saver later on.
  3. Send the unit and completed Service Request Form to us to the address on the form in secure packaging via your favorite carrier.  Insure it for the new replacement value.  Insurance on EFIS units can be expensive.  Ground shipping can cost as much as $20-$30 per display unit with insurance.

How long will it take?

Most upgrades have a turn-around time of one week.  Plan to have the aircraft down for 2 weeks to allow for shipping both ways – more if outside of the continental U.S.

I have a dual-screen system.  Can I update one screen at a time and keep flying?

Individual systems vary, but it won’t hurt the remaining EFIS if you fly the airplane with one EFIS missing out of a multi-EFIS system.  Make sure the connectors and wiring harnesses are not flopping around loosely. Learn (or remember!) your electrical system first because GPS units, autopilot, and other items normally wired to the missing EFIS will not work unless they are wired to the unit that’s left. Do not attempt to fly without the AHRS, as the flight instrumentation will not be present.

What will GRT do with my display unit?

We will take in your original unit and replace the parts affected by the upgrade.  For a screen size increase, we remove the bezel and screen and replace them with new ones.  Other upgrades require disassembly of the main unit and replacement of processors or loading of software.  Unless you specifically order new wiring, plan to reuse your original wiring harness and connectors.    

What is a Dual AHRS Upgrade?

An upgrade from Single to Dual AHRS requires trade-in of the Single AHRS and magnetometer.  You will get a taller Dual-AHRS unit (4.25” total) that fits on the same footprint, a pair of magnetometers (one calibrated to match each AHRS), and a new wiring harness for the second AHRS.  Run the new harness next to the existing harness and use them both in the finished installation – one for each AHRS connector. You will also need another set of pitot/static lines to connect to the second AHRS/Air Data Computer.  The single AHRS kit with black magnetometer and wiring harness is shown here, with a Dual AHRS unit on the right for comparison.

Screen Upgrades

Both Sport and Horizon units were originally designated “WS” for “wide screen” and HS for “high-res screen”.  All Sport and Horizon units (except HXr) use the same bezels and displays.  Screen sizes are given in standard diagonal screen dimensions.

Upgrade WS to HX or SX - A taller, higher-resolution, 6.5” or 8.4” 640 x 480 screen.  Enables display of EIS engine data across the bottom of the screen.  Both screens add 7/8” to the overall depth of the original WS unit.  See a comparison of the WS and HX displays in the photo below- the display of the HX (left) is taller and thicker than WS (right), but the same width.

Instrument panel cutout differences are as follows:

NOTE:  As of October 2014, parts are no longer available for the HS screen-only upgrade.  WS units may be traded in toward a new HX and SX display until January 1, 2017.

Trade in an older Horizon for an HX

Get the increased processing power of HX with 30-mile synthetic vision, 8 high-speed serial ports, and built-in ARINC 429.  

Upgrade HX to HXr

HX to Hxr - Keep the same wiring, but upgrade your whole interactive experience. With HXr, you can remote mount your radio stack and enjoy a huge screen with a simplified pilot interface.

Sport Upgrades

Synthetic Vision - 10-mile 3D terrain on PFD with shaded color map.  Draws runways and obstacles on PFD as well.  Requires 6.5” or 8.4” HS screen and CPU upgrade.

Vertical Commands Software - Upgrades the basic lateral GRT Sport autopilot to the full package with vertical navigation.  Best used with the optional ARINC 429 module coupled to appropriate precision approach navigation equipment.  Can be used with WS units.

Dual AHRS - Adds internal AHRS to secondary S100 multi-function display unit in dual-Sport system. Requires one serial port.

We are phasing out the trade-in program for the original Horizon I and Sport WS/HS units. The trade-in value will drop each January until 2017, at which time we will no longer accept them.  Please click here for current upgrade and trade-in values.