This study analyzes existing approaches to building fault-tolerant onboard systems at the hardware and software levels. The main advantages of constructing an Avionics Integrated Vehicle System (AIVS) based on fiber optic components are considered, particularly for deploying a Unified Intelligent System (UIS) that provides intelligent decision-making in case of abnormal situations. Scenarios for countering various abnormal situations at different levels of aircraft equipment complex (AEC) operation are developed, aiming to enhance the fault tolerance of its systems and, consequently, flight safety as a whole. Algorithms for reconfiguring the AIVS in case of abnormal situations, both during flight and on the ground, are devised. Principles for creating a specialized knowledge base for information support (KBIS) based on operational documentation are proposed. Logical programming methods are employed to simplify the formalization of knowledge stored in the KBIS and to facilitate modification and supplementation of the KBIS with new data. Calculation methodologies for AIVS configuration characteristics based on the KBIS are developed. Dynamic synthesis methods for generating new AIVS configurations are designed to address abnormal situations arising during aircraft operation. State space information formalized using logical programming methods is used to solve the synthesis problem. A complete system graph is constructed considering its redundancy, and a search-synthesis for the most suitable AIVS architecture capable of countering failures is performed.