Consider these basic questions when you shop for an EFIS.
The AHRS. Remember that this is the part of the system that senses attitude data. Without high integrity attitude data, an EFIS is unsafe, and useless. While this is the most critical aspect of the system, we have noticed that customers often fail to question the integrity of this data.
Does the AHRS provide attitude data without requiring pitot/static or GPS data aiding? ...our AHRS does not require pitot/static or GPS data aiding to provide high integrity attitude data.
Does the AHRS incorporate a processor dedicated to these calculations? ...our does. These calculations are time-critical. An interruption in this processing can compromise or destroy the integrity of this data. A dedicated processor is required.
Does the AHRS include power-up and continuous built-in test functions? ...ours continuously performs tests on all sensors, the processor, memory, and a/d converter.
What ability do the AHRS have to detect bad attitude data? ...ours uses GPS data to perform a mathematical consistency check against the attitude data.
General Considerations
Is the hardware specifically designed for use in an aircraft, and is it tolerant of the electrical environment, especially with respect to tolerance of EMI/RMI (electromagnetic interference due to radio transmissions and noise generated by the ignition system). Is the hardware tolerant of wiring errors? ...our is. We have over 12 years of experience producing aircraft instrumentation. Over 25,000 EIS engine monitors have demonstrated our expertise. Don't under-estimate the importance of this criteria. After all, you want hardware that works in your airplane, not just on the bench!
Is display readable in direct sunlight? ...ours is. Over what temperature range? ... our wide temperature range won't pose a limitation to your flying.
What impact does loss of the EFIS have on the operation of the airplane? ...our system is designed not only to allow redundancy in its configuration (with multiple display screens and/or AHRS/Air data units), but also so that the GPS and autopilot are not dependent on the EFIS...after all, do you really want to loose your GPS and your autopilot with loss of the EFIS?
What provision does the EFIS have for growth? Our Horizon EFIS includes six serial inputs, six serial outputs, 14 discrete outputs, 5 analog inputs, inputs for localizer deviation and validity, glideslope deviation and validity, and ARINC 429. The GRT Sport has 4 serial ports and ARINC 429 and similar design qualities as the Horizon.
How does the GRT EFIS compare with the other EFIS?
There are 3 “levels” of differences.
The First Level
The obvious differences are the size and functionality.
This size of the display unit is large enough to allow the artificial horizon to look "natural", that is, like a synthetic view of the outside world (complete with airports and obstructions), and still have room for both tapes and large digital displays of airspeed and altitude.
At the same time, the size is small enough to allow multiple displays on small instrument panels. Since each Horizon display unit can display any data (primary flight data, moving map, graphical engine data, or a split screen of any 2), the use of 2 display units provide twice as much viewable data, while at the same time, adding redundancy. This also allows for a simple means to expand your system to meet future avionics needs.
Our EFIS has an extensive set of features, including integrated navigation/attitude displays on the wide-format primary flight display, graphical engine monitoring, moving map, and also include interfaces to the autopilot, localizer and glideslope inputs, weather and traffic.
The difference in architecture, that is, the ability to use multiple display units independently, vastly distinguishes us from single screen EFIS concepts. Those familiar with commercial jets will notice similarities in architecture (and functionality) with our equipment, and this is no accident.
This first level; the built-in functionality that makes the automated cockpit a safe, effective, and efficient environment.
The Second Level
These differences are more subtle. Our specification includes a wide operational temperature range, direct sunlight readability, and hardware designed specifically for aircraft use. The hardware design is based on the design principles and lessons learned developing our industries permier Engine Information System (EIS), and more than 20 years of aerospace experience. Our design is robust, tolerant, and ready for real-world exposure to wiring errors, radio and electromagnetic fields, etc.
This second level; quality is designed in.
The Third Level
These details are usually unseen, but are what distinguishes aviation equipment from non-aviation equipment. It includes the selection of components suitable for use in an aircraft environment, and also relies on a failure modes and effects analysis. This analysis results in features and functionality (built-in diagnostics and self interrogation) that add integrity. High integrity means a low probability of an undetected failure of any of the flight critical data provided to the pilot.
This third level; safety is designed in.
Conclusion
What sets our systems apart is engineering and experience. The GRT Sport and Horizon Series I EFIS provide aerospace grade design, quality, and functionality at affordable prices.
