To consider the corrosive effects on aircraft structural life under natural environments, we
have the calendric life to represent its impact. A new concept of Aircraft Structural Life Envelope
(ASLE) to consider the combined effects of fatigue loads and corrosive conditions is developed and
the sketch of ASLE is presented, then the basic determining methods of ASLE under different
corrosive conditions are obtained too. Finally the linear damage cumulative rules are employed to
analyze the usage of aircraft in different corrosive conditions, and the residual fatigue life and
calendric life of aircraft structures can be predicted and supervised.