This SAE Aerospace Standard (AS) specifies minimum performance standards for Electronic Displays which are intended for use in the cockpit by the pilot or other flight personnel under standard and other environmental conditions. The four basic types of displays based on function and criticality are covered as follows:
Airborne Electronic Displays can include one or more of the following interconnected components. Other configurations are possible.
Symbol Generator/Processor Unit (SG) containing display processing and symbol generation processing and symbol generation capability, power supplies, interface logic/buffer circuits and Display Unit interface capability. The SG receives data from external sources, produces symbols as electronic signals, and transmits the symbols to the Display Units(s).
Control Panel (CP) is an optional component providing the means for manually selecting display symbology options/modes, selections, settings, brightness, etc.
Display Unit (DU) providing the visual display of SG symbology. In the case of Head Up Displays, this information is combined with a view of the real world. The minimum performance standards for Head Up Displays given in AS8055 are applicable.
Electronic display systems covered by this document are displays whose failure may lead to loss of critical displayed information. System design or installation must recognize this characteristic and include appropriate redundancy criteria where applicable.
ARP4256 gives recommended means, but not the only means, of compliance to this standard for Part 25 LCD displays. That document is subject to change to keep pace with experience and technical advances. A similar document for Part 23 aircraft does not exist.