Upgrading to a Glass Cockpit – How Do You Get All Those Systems Working now?
December 19, 2016 | BY: Nick Churchill
The average transport aircraft in the mid-1970s had more than one hundred analog cockpit instruments and controls. This meant the primary flight instruments were crowded with indicators, crossbars, and symbols and the growing number of cockpit elements were competing for cockpit space and pilot attention. Analog components can also represent data that is hard to store and today such information may be required for regulatory, safety or operational optimization reasons and digitization becomes necessary.
In contrast to mechanical displays, glass cockpit displays rely on computerized systems that integrate multiple data inputs and controls. They can present more information in the available space than conventional instrument panels. Some of the systems that interact directly with glass cockpit displays are:
- Attitude and Heading Reference Systems (AHRS)
- Air Data Computers
- Temperature probes
- Cockpit Voice and Flight Data Recorders
Glass Cockpits have the capability to exchange electronic messages via interfaces such as ARINC 429 where message labels identify the source of the data from and to LRUs. However, many systems on an aircraft may not have the capability to integrate with a glass cockpit and thus require conversion through a data concentrator or replacement with a new compatible system.
Thus, when installing or upgrading to a glass cockpit there is an opportunity to use cutting edge, highly functional LRUs that adhere to today’s and all foreseeable upcoming regulations, rather than invest in other systems to convert the data. The decision of which route to take will depend on the specifics of the aircraft, its future role and a cost benefit analysis.
Whichever route is taken; the glass cockpit can then become a hub for sending data to other systems. For example, Flight Data Recorders (FDR) have traditionally received an ARINC 717 stream of compiled data directly from a data concentrator or Flight Data Acquisition Unit (FDAU). Some modern recorders will accept ARINC 429 data directly from digital systems such as glass cockpit displays. This also makes them ideal for applications such as Flight Data Monitoring (FDM), where they remove the need for a separate data acquisition unit and recorder.
So when upgrading to a glass cockpit or integrating them onto new platforms, one must consider not only how to get information into the unit, but how information from the unit may help with other applications and reduce LRU count and simplify systems integration. You can read more about this in the Optimally Utilizing Glass Cockpit Displays whitepaper.