Copyright © 2013  Grand Rapids Technologies, Inc.

Electronic Flight Instrumentation for Experimental Aircraft Since 1991

“This is why I love my GRT!”


Time-Tested Reliability Backed by Airline-Grade Experience

We’ve been in the business of designing and manufacturing electronic instrumentation for experimental aircraft for well over two decades. Before following his passion in the experimental world, our president and chief engineer began his career designing navigation systems for the airlines and military. Our equipment is some of the most robust stuff in the industry, with the original Horizon 1 EFIS screens and 20-year old EIS “antiques” still commonly seen in airplanes flying all over the world.   


Open Interface Design

GRT EFIS systems have always been designed with versatility in mind. The more ways the EFIS can communicate, the greater the variety of devices it can use. Because every airplane has a unique mission and budget, GRT systems are designed as an “open interface,” which gives builders a wide range of choices for radios, transponders, ADS-B receivers, and other devices.


Customization & Support

No matter if you want a single EFIS screen with basic flight instruments or an IFR powerhouse with dual or triple redundancy, GRT systems are flexible enough to handle it. Flexibility and customization has always been a strong point of GRT equipment due to the very nature of the experimental aircraft market. People want what they want, and we want our EFIS systems to play nice with all the cutting-edge avionics out there. While customization is great, it can also be overwhelming for some builders. That’s why we are dedicated to providing top-notch tech support to our customers. While our techs are always here to help you over the phone, our online documentation library is ever-growing. In addition to manuals for GRT-manufactured equipment, we also write Equipment Supplements to explain explain in detail how to wire and program devices made by other companies to interface with the GRT EFIS of your choice. Check the website often–we write most supplements based on customer demand and the list is always growing. If there is a supplement you need for your installation, email Katie Bosman and we’ll get started on it.  


Designed With Upgrades In Mind

We know that while an aircraft can stay airworthy for fifty or sixty years, electronic technology is always evolving. That’s why our systems are designed with upgrades in mind. For example, when the larger 8.4” screens were introduced for the Sport and Horizon HS, the inner mechanics of the display unit stayed the same to enable easy upgrade to the bigger screen. We take older GRT EFIS systems in trade for new systems as our customers update their instrument panels. We continue to support older systems with new software updates. The modular nature of our systems makes it easy to design the new ones with major consideration for the mechanical requirements of the legacy systems; For example, the same AHRS and Magnetometer mechanical units work with all of our systems, but their software is updated regularly. The logic for wiring, programming, and using the system remains constant from revision to revision so customers don’t have to relearn an entirely new system every time they upgrade.


Made in USA

Made in Michigan, in fact. The circuit boards are populated to our specifications here in Grand Rapids. The display unit bezel is CNC machined from aircraft-grade 6061 aluminum billet right here at our facility and powder coated a low-glare black for durability. Whatever can be made here IS made here. All units are wired, assembled, calibrated and bench tested right here in our shop. This means that if you ever should have a problem with your unit, simply send it back to us and we will either fix it or replace it. All of our EIS and EFIS display units have a 3-year warranty.

Electronic Flight Instruments (EFIS Systems)


Engine Monitors


Compatible Avionics Made by Other Companies


GRT Remote App for Android


GRT Commercial AHRS


Pricing & Options


Display Unit Upgrade Pricing


Products