Avionics systems must be carefully designed due to their criticality since fault may lead to loss of life. Thes e systems must be verified and certified. However, design of avionics arc hitectures becomes more and more complex due to an increasing demand of new functionalities. It makes very diffic ult to analyze systems and detect potential faults that may cause damages. This paper presents an approac h to model and validate avionics systems. Architecture requirements, properties and constraints are described with the Architecture Analysis and Design Language (AA DL) and its associated A RINC653 annex. Then, we apply validation rules to check system correctness and constraints enforcement. This approac h provides a high-level view of the system and eases the development of avionics system by validating their requirements at a model- level, before any implementation efforts