In the past 10 years, full scale fatigue tests were undertaken for two types of aircraft groups, and correspondently, the acoustic emission based integrated non-destructive testing means was used for the early detection of fatigue damages throughout the test. What accompanied the full scale fatigue test was eventually a health monitoring process for the aircraft. During the test, researchers needed to know when the aircraft "got ill" and what remedy measure was required to make the aircraft "recover." A variety of techniques have found important applications in the structural monitoring. Studies were made of various means and the role of health monitoring of aircraft structures and of some special problems to be solved for each method. Comparisons were made for various monitoring methods and the most suitable one was chosen for the full scale aircraft under test. A carefully designed NDT scheme plus AE monitoring was eventually selected as the first choice to complete the task and was shown rather effective in early damage detection for the aircraft under fatigue test although very high risk was confronted throughout the test.
