Digital avionics data bus can be an important enhancement for future general aviation aircraft system. The reliability and stability of the adopted technology should be examined under system configuration design. Controller Area Network (CAN)-based data bus technology has presented its function capability for such applications. This paper surveys the reliability concerns on a redundancy design of CAN-based avionics system. The time triggered protocol (TTP) is added onto a dual bus configuration to improve the system reliability and stability. System design and simulation on different scenarios are tested to verify the system performance. TTP-CAN hardware and software may become an acceptable data bus system design standard to meet aviation requirements.