Copyright © 2016  Grand Rapids Technologies, Inc.

Electronic Flight Instrumentation for Experimental Aircraft Since 1991

Mini Screenshots

Mini User Documentation

Mini Pricing

Mini 4.3” EFIS

A Primary and A Backup

The Mini is not a compromised instrument. It is a complete EFIS capable of synthetic vision, with a GPS navigator, and incorporating the same technology that made GRT famous for its high-integrity AHRS.  It is completely suitable as the primary instrument in your panel or as a backup.

As A Primary Flight Display

The Mini includes an electronic attitude source (AHRS) that is not dependent on GPS and/or air data.  IFR certifiable altitude, vertical speed, and airspeed are boldly shown with tapes and smoothly rotating drum-style digital displays that instinctively convey value and trend. Internal or external GPS navigation and steering data is provided on the PFD, and the -X and -AP variations include highway-in-the sky guidance to any runway in the database. The addition of the external magnetometer adds heading and winds.

Mini features:

A Full-Featured Moving Map

Based on the moving map in the Sport and HX, the moving map has the features you would only expect to find in a full EFIS.  It includes such features as terrain relief, relative terrain height color coding, nearest functions, airport details including frequencies and runways, and much more. When connected to an external GPS, its flight plan and steering information can be displayed on and drive the map.

Smooth Rotation Moving Map

Hand-held or panel mount GPS navigators update their display once per second.  Some EFIS based moving maps do same. The result is a jerky and delayed map.  The Mini combines AHRS and GPS data to update its map at up to 15 times per second, resulting in a smoothly rotating map.  Rolling out of a turn precisely on track becomes easy and the extended runway centerlines eliminate the guess work, making navigation easier and more precise.


When equipped with the moving map, the Mini-X and Mini-AP extends its role by coupling to other navigation sources, such as navigation radios. The Mini includes and OBS (radial) selector for VOR or LOC/ILS navigation. Lateral and vertical deviations are also displayed on the primary flight display.

Integrates With Other GRT Equipment

The Mini adds automatic cross-checking of its attitude with any GRT EFIS screen. The GRT EFIS flight plan is displayed and may be edited on the Mini. Baroset and dimming is shared.  In short, it adds another screen to your GRT equipped panel with complete integration via the inter-display unit link.

NEW!  Angle-of-Attack (AOA) Sensing/Stall Warning

Angle-of-attack sensing is now available for all current models of the GRT EFIS and as an upgrade to all versions of the Mini-EFIS,  SX200A EFIS (identifiable by their digital magnetometer) and Adaptive AHRS.  Sensing is via a two-port 45 degree pitot tube, such as those commonly available from a variety of manufacturers, or using a probe fashioned by the builder.  This method has no moving parts, and allows the use of heated pitot tubes that preserve the stall warning function even in the presence of icing.

The GRT Avionics AOA function drives on-screen AOA symbology that shows too fast/too slow/optimal approach speeds, as well as stall warning.

In addition, an audio output is provided on the SX200A, HX, and HXr display units.  This audio provides an approaching stall warning annunciation (a pulsating tone that varies with proximity to the stall warning angle) and a solid tone indicating stall is imminent.

Using Another Brand EFIS?

All versions of the Mini bring high-integrity attitude and air data to your panel, plus backup navigation that adds comfort to any situation. The Mini-AP adds even more! When the Mini-AP autopilot is engaged and being commanded by another EFIS,  you are  effectively provided with automatic attitude cross-checking, while enjoying the accuracy and ride comfort which made the GRT autopilot famous.

Quality Throughout

We don’t compromise on quality and it is evident before even turning the Mini on. The faceplate and case are milled from aluminum billet, protecting the instrument from physical damage, and providing structural integrity to your panel. Robust ports for the pitot/static connections mean you won’t be chasing pitot/static leaks here.  The buttons and knobs, the parts that get the most physical use, are also examples that quality was and always will be the first priority. We have used a Grayhill rotary encoder for the knob input.  While they are more expensive, costing over $20 in quantity, they have performed flawlessly since we began using them, and we’re not willing to compromise with anything less.

Which Mini Do I Need?


This is the basic backup. It provides attitude, directional gyro slaved to GPS ground track, airspeed, altimeter, vertical speed, and backup GPS navigation.  Coupling to an external GPS shows its go-to way-point info and steering on the PFD screen.

Features include:


For only $200 more than the Mini-B, the Mini-X adds an synthetic view of your world, including terrain, obstacles, runways, and even a 3-D flight plan. The Mini-X is also compatible with the digital magnetometer (can be shared with the Adaptive AHRS), providing magnetic heading, wind speed and direction.

Features include:


Planning on the Mini-X with the external magnetometer? Want full autopilot capability? Why not move up to the mini-AP?  It includes everything the Mini-X includes as well as:  

New Optional Feature Set!

Introducing a new optional feature set for all of our Mini versions!  Add the functionality to the Mini that you would expect from a full-size EFIS, making the Mini a practical, low-cost primary instrument for any airplane at an AMAZING price!

             -ADS-B not available for Mini-B.

Engine Monitoring

Practically identical to the engine monitoring provided by the HX and Sport SX, the Mini engine monitoring provides 6 engine pages, percent power calculation, and GRT exclusives (such as the EGT and CHT time histories and engine efficiency via the specific fuel consumption display).

Probably the most popular of the engine monitoring screens is the EGT time history page.  In addition to two user-programmable dials, fuel management, and basic engine data.  This screen includes a 2-minute history of all EGTs.  This GRT exclusive allows you to effortlessly distinguish between engine problems affecting one cylinder or the engine itself.  It also makes it easy to see small changes in engine operation that might not otherwise be noticeable.  Even better, this display provides reassurance that your engine is running normally, even when flying over water or at night.  If the EGTs are steady, so is the engine.

Shown here, you can see some unusual fluctuations in the white EGT time history (cylinder 1).  The rise in EGT 1 temperature near the center of the time history suggests a spark-plug might be intermittently fouling, causing the EGT to increase, and then return to normal.  This subtle change in engine operation would probably not be felt, but becomes obvious thanks to this exclusive feature.

The traditional EGT/CHT bar graphs are provided by this screen.  This page makes it easy to see how far your engine (especially the CHTs, which reflect engine cooling) are from their limits.  The lack of time history makes this page less useful for detecting abnormal engine operation than the EGT time history screen.

CHTs are also displayed with a time history on this page.  When managing engine operation to control CHTs (such as during the climb to cruising altitude), this display makes it easy to see if CHTs are still climbing.  In this screenshot it is easy to see that the engine had been operating at low power, causing the CHTs to drop.

The Statistics page provides useful data, that like the EGT time history, you will find you can’t live without.  The MPG page allows you to find the airspeed that optimizes fuel economy to account for altitude and winds.  The specific fuel consumption (SFC) indicates the amount of fuel (in pounds) being burned to make one horsepower for one hour.  This reflects engine efficiency.  If this value increases (on a fixed-pitch prop) or changes up or down (constant-speed prop), you need to lean again.  Without this GRT exclusive, there is no way to know if you need to lean again due to changing conditions.

Four user-programmable dials allow for easily-readable engine data.  Excellent for piston and turbine engines.  The dials allow user settings for color bands, bugs, scaling, resolution and much more!

Need more customizing?  The Bar Graph page allows you to customize this page with bar graphs across the entire screen.  That big black area is yours to customize.


Real-time traffic and weather is now a practical reality, and it is fully supported by the Mini.  Unlike a tablet, the Mini’s screen is always readable, remains fully controllable in turbulence, and doesn’t suffer from overheating problems.

NexRad weather radar showing the intensity of precipitation.  This screenshot was taken with a range of 150 nmi, providing plenty of anticipation for approaching conditions.  Note the top-of-climb is the location predicted by the green arc.

ADS-B weather on a 35-mile range.  Note that weather is shown relative to airports and surrounding airspace.

Airports are color-coded to show VFR, marginal VFR, IFR and marginal IFR conditions.  Wind barbs are also shown, depicting surface winds.  (Actual screenshot from a demo recording by James Clark)

METAR and TAF data is provided in the text on the airport details for all airports providing weather.  Provided in “Airport Details” this data is only two clicks away for your destination airport, and is easily selectable with the GRT exclusive “radar sweep” data selector.

Traffic is overlaid on the moving map, and also appears on the primary flight display.  In this example, traffic is clearly visible 600’ above the airplane, tracking off the left side of the airplane.  Alarms are generated if traffic poses a safety threat.

(The following features are standard on the Mini and not a part of the new Feature Set.)  The Mini provides a conventional HSI display, driven by the navigation mode selected on the Mini.  In this example, it is being driven by GPS data, but will also show ILS and VOR data.  ADS-B traffic of unknown altitude is shown with a ground track passing behind the airplane.

Traffic is obvious here, as well as a TFR outlined in red.  Pressing the right knob brings up the data selector, allowing  the pilot to easily select this airspace for more details, as shown below.

Note the brief description of the TFR provided, and details are one knob press away.


The GRT App for Android now interfaces with our Mini via the Bluetooth link in our new feature set!

Click here to download the app now!

The moving map in arc-view mode. Notice the color-coded terrain.

Clicking the right knob brings up a short-cut menu that

provides commonly used functions on the softkeys, as shown.

The battery is fully charged and external power is being used.

The primary flight display screen terrain showing relative height. In the upper left the autopilot/flight director mode is shown as synthetic approach to runway 35. The flight director is commanding a slight pitch down in the center of the screen. The airspeed and altimeter drums move smoothly and the high-contrast digits make them highly readable. Extending up from the runway is the way-point balloon.





Airspeed Indicator


Attitude Indicator

Magnetic Heading With Remote Magnetometer


Turn Coordinator

Vertical Speed

Wind Vectors



Remote Transponder Controls*

Serial Altitude Encoder

Serial Link to GRT EFIS*

Sunlight Readable LED Display

Wide Viewing Angle

480 x 272 Hi-Res Screen

Data Logging

Autopilot Controls


Heading Bug

Altitude Bug

Flight Director


ARINC 429 Interface


GPS CDI  Needle

Highway In The Sky

Synthetic Vision

Stand-Alone GPS Navigator

Moving Map


Internal 5-Hz VFR WAAS GPS

Glareshield GPS Antenna

GPS Serial OUT

Input for External GPS

OAT (for TAS, Density Alt)




Internal Battery Backup




Voter for Dual AHRS



Feature Set  (Engine Page,

ADS-B, Audio Output and Bluetooth)

Optional (Except




Base Price




Optional Remote Magnetometer




Optional Moving Map




Optional OAT probe*




Optional Internal Li-Ion Battery*




Optional Software Feature Set

$150 (Engine Pages Only)



Optional ARINC 429




Standard GRT Pitch/Roll Servos*




High-Airspeed Air Data Option For Above 335 MPH IAS


Must be specified at the time of order.

Optional Angle-of-Attack (Direct Sensing via Dual Port Pitot Probe)