Recently, aircraft structures adopt a damage tolerance design and its airworthiness is
maintained through the periodical inspections specified in the maintenance plan before it becomes
fatal. The establishment of health monitoring technology to continuously monitor the condition and
airworthiness of an aircraft structure will hopefully lengthen the present inspection intervals and
reduce maintenance costs, thereby improving the efficiency of aircraft operation. The authors
developed an optical fiber sensor-based system for wide-area diagnosis of aircraft structures and
evaluated its applicability to adopt structure condition monitoring through flight demonstration
testing. It was found that the developed system can monitor the structural condition during flight
operation.