Considerations for upgrading aging military avionics systems with state-of-the-art technology

Due to ever tightening budgets in the defense arena, the armed services are making conscious efforts to extend the service life of existing aircraft beyond what was intended at the time of their original design. These aircraft types include extremely old airframes such as B-52H and variants of the C-130, which continues to play a part in 21st century military actions. Relatively new weapons systems are also included, such as the F-117A and B-2A, which are already beginning to experience component obsolescence problems. A major aspect of these upgrade programs involves replacing existing aging avionics with modern digital systems that are more reliable and more capable. In many cases, however, these retrofits are not simply "plug-and-play". Careful analysis is required to ensure that no existing capabilities are lost and that the new system can function properly in the legacy aircraft. These considerations can vary depending upon aircraft type and mission. Factors are to consider include interoperability with legacy systems, aircraft mass properties, A-kit wiring, human factors, training, and growth capability for future upgrades. The paper provides guidance on the evaluation of a potential retrofit, thus assisting the readers in developing their own decision support system.