Federated Avionics Architecture
Section 11: Aircraft & Avionics Architecture
Definition
An avionics system architecture in which each system function is implemented in a dedicated, self-contained Line Replaceable Unit (LRU) with its own processor, memory, I/O interfaces, and power supply. Each LRU communicates with other LRUs over point-to-point or shared data buses. In a federated architecture, functions are isolated by physical separation: each box performs one or a small number of related functions.
Where This Shows Up
Federated architectures dominated avionics from the 1970s through the early 2000s and remain prevalent in many aircraft types. The primary advantage is fault isolation: a failure in one LRU does not directly affect others. This simplifies certification because each LRU can be developed, qualified, and certified largely independently. However, federated architectures result in significant weight, volume, power consumption, and cost due to the duplication of computing resources across many separate boxes. Maintenance is straightforward with a one-function-one-box paradigm, supporting rapid LRU replacement at the line maintenance level.
Primary Sources
Guidelines for Development of Civil Aircraft and Systems — provides guidance on system architecture development including federated and integrated approaches.
Related Terms
Need help navigating certification?
Understanding the terminology is the first step. If you need expert guidance on DO-178C, DO-254, ARP4754B, or any aspect of FAA, EASA, or TCCA certification, our team is here to help.