抄録
The objective of the paper is to seek the significant factors which are anticipated to contribute for the enhancement of the aviation safety of 21^<st> century by reviewing the aircraft accident experiences of 20^<th> century. The paper consists of the following three parts: ○ Examination of statistics of world aviation accident and accident causes. ○ Effect of improvement of survivability factors in aircraft accident. ○ Comparative case studies on the effect of countermeasures after the fatal accident.