Integrated Modular Avionics for A380

The Flight International reported in 2001 that Airbus has selected Thales Avionics to supply the modules for the A380's integrated modular avionics (IMA). The company is, not surprisingly a French avionics manufacturer and it was working with a Germany company Diehl Avionik Systeme. The other candidate was Smiths Aerospace which supplies the common core system (CCS) for the Boeing 787 Dreamliner.

Works started to assist Airbus to define the concept of modular architecture and develop the system.

The Growth of Data Management in Aircraft.

The term DATA is normally used to describe the elements used in the computing. For the purpose of understanding, I am using it to include the command signals and the advisory signals used in the aircraft. That include the physical commands, like the command to turn left or right nose up or down.

A. Mechanical Linkages

In the days of B707, the term data processing was not coined yet. The command signal from the pilot was transmitted to the control surface via mechanical cable linkages. Some of the position indicators can be operated by mechanical cables. The example is the stab trim. The command can be from the pilot turning the stab trim wheel. The position of the stab trim is given the indicator in the central pedestal. The stab position indicator is driven mechanically by the mechanical cable. 

 B. Electrical - example stab trip switch.

C. Digital
a. ARINC 429 - Uses 32bits data words to transmit data. It is a simplex system, that mean, data can only move in one direction. A sender can have a maximum of 20 receivers. 

D. Federated Architecture
The ARINC 629 gave rise to the Federated architecture. is a multi-transmitter data bus protocol where up to 128 units can share the same bus. It was first installed on the Boeing 777. It is half duplex system, that mean a NOD can transmit and receive data, however it has to do it one at a time, when it transmits, it cannot receive and vise versa.

E. Integrated Modular Architecture.
a. Data processing
b. Data transmission. - ARINC 664 defines the use of a deterministic Ethernet network as an avionic databus in modern aircraft like the Airbus A380, Sukhoi Super Jet 100 and the Boeing 787 Dreamliner. The system is based on the commercial internet ( IEEE 802.3). The system is modified to add the deterministic elements as required in aviation. This is required to replace the "best effort" and missing word's packages in the commercial ethernet.