Aspen Avionics – Evolution Flight Displays

The Aspen Evolution flight display system is an affordable, expandable and upgradeable PFD, MFD and hazard sensor cockpit solution for general aviation aircraft. Compatible with existing aircraft avionics, the flexible Evolution flight display system lets aircraft owners install all Evolution flight displays and options at once or separately, as their needs and budgets permit.

The Evolution flight display system EFD1000H Pro is designed specifically for the helicopter flight environment. Both hardware and software are specifically designed to withstand the harsh rotorcraft environment. Four hundred hours of development flight test improvements to the attitude heading reference system (AHRS) algorithms were specifically designed to provide outstanding system performance during those conditions unique to the helicopter operating environment. The system is currently STC’d in the Bell 206 and will be available soon in the following aircraft: Robinson R22/R44, Bell 407, Eurocopter AS350, McDonald Douglas MD300 and MD500 and the Enstrom 480B.


The system is designed to be installed as a single or dual configuration. It is available in one, two or three display configurations. Customers can install a PFD and then add on MFDs at a later time, or they can install everything at once. The EFD display type determines the sensor package (PFD, MFD). Various software options or upgrades are at the discretion of the buyer. Internal air data attitude heading reference system (ADAHRS) sensors are used in the EFD1000H PFD and MFDs to provide primary altitude, airspeed, attitude, heading, etc. In the EFD500H MFD, the sensor package is removed and the display functions as a traditional MFD with optional interfaces to traffic and XM weather systems. The Evolution system is also widely compatible with virtually all analog navigation systems found on today’s helicopters.



Installations are typically performed by an approved Aspen dealer. As with all electronic flight instrument systems (EFIS), there are important installation instructions that must be followed for proper system operation. The most critical aspect of the installation is a proper location for the remote sensor module (RSM), which houses the magnetometer, emergency GPS and outside air temperature (OAT) sensor. Careful evaluation of the proposed RSM location for magnetic interference will prevent poor AHRS performance. The Honeywell HMR2300 (or equivalent) is the best tool for this task. Following installation, a compass calibration procedure must be performed — this may require the helicopter to be moved to a magnetically clean area.

The standard EFD1000H PFD display includes the display, the display vibration isolation mounting fixture, the remote sensor module and the display configuration module. Total system weight is 3.2 pounds. The Evolution flight display system interfaces with other line replaceable units (LRUs) over RS 232 and ARINC 429 buses. The display system employs continuous fault monitoring logic. No special test equipment is required by the end user.

LRU data programming is accomplished through an on-screen installation menu. There is also a micro SD data card used for software upgrades and to store the database in an MFD.


Maintenance tasks are relatively easy and straight forward. The displays employ an antiglare coating, so care should be given when cleaning the displays. The use of a soft lint free cloth and a 50/50 solution of isopropyl alcohol and water or a premoistened lens cleaning tissue such as Bausch & Lomb Sight Savers, or a cleaning solution made especially for LCD displays.

Integral cooling fans cool the display units. There are no filters that need to be checked or cleaned periodically. No color calibration is field required, and the absence of flags and warning/caution annunciations are indication that the displays are operating properly. All maintenance is considered “on condition” unless otherwise noted in the Instructions for Continued Airworthiness (ICA). Internal and external batteries are visually inspected and operationally tested annually.

About the only scheduled maintenance task is to replace the batteries for the displays every three years or 800 hours, whichever occurs first. The batteries are replaceable in the field. There are two types of batteries used with the EFD1000H products. The -101 PFD uses a field replaceable internal battery contained within the display and the -105 MFD option uses an EBB58 external backup battery. The external battery used with the EFD1000H MFD offers extended backup power and is FAA approved as an emergency power source.


Lessons Learned

When removing and/or replacing an LRU, make sure that the maintenance specialist performing the task has successfully completed one of Aspen’s on-line training programs, or attends and successfully completes other training scenarios offered by Aspen. Customers can contact their Aspen dealer for troubleshooting and equipment exchange. In the event of a failure, a replacement unit is shipped overnight once the problem has been verified. All Aspen dealers are required to participate in a training program and pass an open book training exam. The idea is not to force them to study, but to make them aware of the key information in the installation instructions and help them avoid mistakes. Technicians that have completed the Aspen training have a thorough understanding of the components, system operation, proper installation and troubleshooting.

Once an LRU has been replaced, the ICA directs the maintenance specialist to the installation manual for the test procedures, or specific testing defined by the STC.