Using an Open Architecture Approach to Military Avionics

The Genesys avionics suite featured in a UH-60 Black Hawk helicopter. (Image: Genesys Aerosystems)

Genesys Aerosystems, a Moog company, offers a line of avionics specifically designed for the military/special-mission market. Originally, the system was developed as part of the FAA’s Capstone Program — first established in 1999 — to reduce the excessively high number of controlled flight into terrain (CFIT) accidents in the southeast region of Alaska.

Implementation of this technology by pilots in the southeast Alaska region immediately reduced the CFIT accident rate from an average of one fatality every nine days to zero among commercial aircraft. Twenty years later, the Capstone equipment continues to provide exceptional safety, and Genesys has become a leading avionics supplier to military and special-mission fleet operators around the world, including the U.S. Navy, U.S. Army, and over 35 foreign militaries and other government operators.

The Genesys Digital Radio (GDR) is one of the key components of the core digital avionics suite. (Image: Genesys Aerosystems)

The Genesys system is ideally suited to these applications due to its combination of FAA and MIL-STD certification, unique customization and seamless interconnectivity with specialized mission equipment.

The Genesys electronic flight instrument system (EFIS) with synthetic vision system (SVS) and terrain awareness and warning system (TAWS) was the first flight display certified by the FAA to use synthetic vision technology and highway-in-the-sky (HITS) navigation, where the pilot is presented a simulated 3D depiction of the environment ahead of the aircraft, including conformal terrain, towers, traffic, navigation aids, and runways, all generated using FAA-certified databases and sensor inputs. It was also the world’s first Technical Standard Order (TSO) C146 certified global positioning system/satellite-based augmentation system (GPS/ SBAS) navigation system.

The Genesys engine indication crew alerting system (EICAS) display from a CN-235 transport aircraft. (Image: Genesys Aerosystems)

The Genesys avionics suite typically consists of IDU-680 EFIS displays with synthetic vision connected to an embedded flight management system (FMS) supporting all ARINC 424 leg types and all classes of TAWS. Dual air data / attitude/heading reference system (ADAHRS), dual SBAS receivers, Genesys Digital Radio (GDR) and integrated VHF/UHF software-defined digital radios are supported by the system as well.

The Genesys avionics suite is FAA-certified on all four classes of aircraft, Part-23 (small airplanes), Part-25 (transport airplanes), Part-27 (small helicopters), and Part-29 (transport helicopters) for both visual flight rules (VFR) and instrument flight rules (IFR) single and dual pilot operations. The system supports a wide range of performance-based navigation (PBN) procedures, including required navigation performance (RNP) down to 0.1, localizer performance with vertical guidance (LPV) and point-in-space (PinS) helicopter approaches.

The core of the Genesys suite is the IDU-680 portrait display. The IDU-680 is a smart display or a self-contained, independent hardware/software device. All IDU-680s in a system have the same software and carry the same part number and are recursively redundant, meaning any display can perform any system function, regardless of the status of the rest of the displays. The displays also communicate with each other to determine which one is responsible for communication with other equipment when necessary. Up to eight IDU-680s can be included in a single system.

The features shown on this display were developed using the Genesys Open Architecture System Integration Symbology (OASIS) system. (Image: Genesys Aerosystems)

The displays feature a variety of primary flight display (PFD) modes, including synthetic vision with head-up display (HUD) symbology in accordance with SAE ARP-4102/7 and MIL-STD-1787. Additionally, the electronic attitude and direction indicator and basic six pack configuration for primary training are the other core features of the displays. The PFD also provides functions such as flight path marker, Mach number, G-meter with latching tattletale, dual cue flight directors, V-speeds, radio frequencies and hover vector for helicopters.

Navigation modes include color moving map, approach plates, airport runway diagrams along with the status of engines, weather and traffic depicted on the displays. Pilots also have access to automatic dependent surveillance-broadcast (ADS-B) information, alongside audio, radio and video management within the navigation displays. Winds aloft, relative wind direction arrow with direct crosswind component, dead-stick glide area for single-engine aircraft and geo-referenced hover vector for helicopters, are some of the other features of the navigation displays.

Another unique feature of the Genesys system is the embedded Open Architecture System Integration Symbology (OASIS), which allows other devices to be integrated with the displays without changing the Level-A software and without affecting FAA TSOs already issued to the system. OASIS is a software toolkit which allows anyone to independently generate unique symbology and display pages on the IDU-680 display without affecting the Level-A software certification. OASIS can also create customized symbology for overlays on existing certified display pages. OASIS pages and overlays are created with a human-readable text configuration file loaded onto displays and do not require any additional software certification process.

OASIS can read any standard or custom ARINC 429 label from a third-party device and has access to all system discrete inputs and outputs. OASIS also interfaces with certain custom RS-232/422 message data. OASIS can manipulate incoming ARINC 429 data and output modified labels to any ARINC 429 device. It can also activate any of the system discrete inputs and outputs.

Engine Indication and Crew Alerting System (EICAS) customization is accomplished by using a library of DO-178B Level A software elements. The appearance, arrangement, and behavior of these elements are defined using a configuration file, so the core EFIS software is not affected, thereby eliminating the need to recertify software when changes are made.

The individual components that make up the Genesys attitude/heading reference system (ADAHRS). (Image: Genesys Aerosystems)

Open architecture symbology provides virtually unlimited capability for future self-sufficient growth. Extensive customization as well as changes late into flight test programs can be accommodated without impacting certification schedules. OASIS functions only require acceptance testing at the aircraft level instead of lengthy software certification testing. Up to 1,024 custom crew alerting system (CAS) messages can be created in an OASIS configuration file. CAS messages can appear on the PFD and/or in a CAS box on any page. CAS messages can be assigned advisory, caution or warning visual alerts and can be assigned any of the system aural alerts or custom sounds. In addition, CAS messages can be entirely logic in nature with no visible text or audible sound.

In this manner, CAS messages can be used for complex Boolean logic functions which are used to manipulate the behavior of other OASIS elements and functions. CAS alerting is provided redundantly by each display so there is no single point of failure, thus allowing the traditional CAS panel with discrete lamps to be removed entirely.

Each display in a system can contain up to 10 custom OASIS pages. Each page can support up to 1,024 elements. Synoptic pages can be developed to easily display specific conditions of aircraft hydraulic, electrical, and fuel systems, for example. Pilot-selectable overlays allow any OASIS symbol to be conditionally or optionally displayed on most EFIS function pages.

Limits and exceedances can be configured for each element to determine caution and warning levels. This can determine when and how the alert is displayed to the crew. Each OASIS element can be linked to the source ARINC 429 label value with a math operator to define appropriate gauge ranges, limits, and exceedance logging.

The Genesys IDU-680 is also U.S. Department of Defense (DOD) Modular Open System Approach (MOSA) friendly. The established interface used by Genesys is the industry standard ARINC 429 Mark 33 digital information transfer system.

Any of these devices can be replaced with an ARINC equivalent simply by wiring to the display and editing the display configuration file. Any new device not supported natively by the displays such as threat warning or self-protection systems can be enabled through OASIS provided the interface to the displays is ARINC 429 or can be converted to ARINC 429. All platform-specific OASIS pages and symbology become the intellectual property of the customer. The Genesys ADAHRS weighs less than one pound, and the Genesys GPS/SBAS receiver is mechanically similar.

One of the wide area augmentation system (WAAS) receivers developed by Genesys. (Image: Genesys Aerosystems)

The majority of individual communications, navigation and surveillance equipment can be substituted in a Genesys system with any equivalent MOSA (ARINC 429) device, including the mission computer, video sources and engine data acquisition unit among others. Some of the other pieces of equipment that can be substituted include the flight data recorder, traffic collision avoidance systems, distance measuring and geo referencing equipment.

The GDR software-defined radios combine VHF communications from 118 to 156 MHz, UHF from 225 to 400 MHz, VOR, LOC, GS, and marker beacon in a form factor that weighs less than four pounds.

The Genesys EFIS is FAA-approved on more than 740 fixed-wing and helicopter models. Some of the certified applications that are in-service today include the following:

  • Aero L-39G

  • Airbus EC-145

  • Bell 412

  • PTDI CN-235

  • Dornier DO-228

  • Lockheed Martin C-130

  • Mi-17

  • Mi-24

  • Sikorsky H-60 Black Hawk

  • Sikorsky Sea King

This article was written by Gordon Pratt, Founder, Genesys Aerosystems. For more information, contact This email address is being protected from spambots. You need JavaScript enabled to view it..