A variety of glass waveguide devices, including passive components (splitters and couplers), active network components (waveguide switches, lasers and amplifiers), and sensors for the measurement of pressure acceleration, position, rotation, etc, are in various stages of development, or have reached the production stage, at various companies. These components are expected to have a major impact on the implementation of fiber-optic (FO) systems for aircraft. Many new functions and applications can be realized with their introduction. This paper examines factors which have so far delayed the introduction of these products. Applications of FO and integrated-optic (10) technologies, and the potential of glass waveguide devices in aircraft systems, are discussed.