<title>Fly-by-light status: issues and options</title>

All-passive fly-by-light technology has been considered to replace the conventional fly-by-wire control systems in aircraft. Both the sensors and their associated interfaces providing data to the flight control computers have been developed. Primarily, two types of electro-optic interfaces and four different types of Fiber Optic technologies have been demonstrated for sensors/switches. Comparison data shows the development of passive TDM flight control technology is near production-ready, but the digital optical position sensors and switches are prohibitively expensive. Two innovative approaches are required for improving producibility and cost of the TDM sensors. Sensors based on other techniques require substantial development to meet system requirements and are still in their infancy. System, device and manufacturing engineers must work closely to implement system requirements and concurrent engineering approaches at early stages if the fiber optic technology is to move from the laboratory to production aircraft.