Aircraft structures are highly complicated mechanical systems that demand constant maintenance in order to ensure safety and airworthiness. The requirements for structural integrity lead to various structural health monitoring processes, such as operational load monitoring. This book describes the development of an advanced smart load monitoring system based on optical fiber Bragg grating sensors for a UAV composite tail boom. The smart load monitoring system comprising optical interrogator, controller computer and embedded optical fibers, was integrated into the airframe and was able to measure real-time strain sequences during ground tests and real flight conditions. The strain sequences that were obtained from these tests were analyzed and infused to load monitoring evaluation by using different signal processing techniques. It was demonstrated that the system could track the development of small strains in the booms and was also able to identify all major natural frequencies and mode shapes. The result of this evaluation gave comprehensive information about the mechanical behavior of the aircraft structure parts and verified the feasibility of the sensing system.