The importance of learning and understanding effective  ADM skills cannot be overemphasized. While progress is  continually being made in the advancement of pilot training  methods, aircraft equipment and systems, and services  for pilots, accidents still occur. Despite all the changes in  technology to improve flight safety, one factor remains the  same: the human factor, which leads to errors. It is estimated  that approximately 80 percent of all aviation accidents are  related to human factors, and the vast majority of these  accidents occur during landing (24.1 percent) and takeoff  (23.4 percent).  ADM helps reduce risk. To understand ADM is to understand  also how personal attitudes can influence decision-making  and how those attitudes can be modified to enhance safety  in the flight deck. It is important to understand the factors  that cause humans to make decisions and how the decision- making process not only works, but also can be improved. This chapter focuses on helping the pilot improve his or  her ADM skills with the goal of mitigating the risk factors  associated with flight. Advisory Circular (AC) 60-22,  Aeronautical Decision Making, provides background  references, definitions, and other pertinent information about  ADM training in the general aviation (GA) environment.  [Figure 5-1]  For over 25 years, the importance of good pilot judgment, or  ADM, has been recognized as critical to the safe operation  of aircraft, as well as accident avoidance. Research in this  area prompted the Federal Aviation Administration (FAA)  to produce training directed at improving the decision- making of pilots and led to current FAA regulations that  require that decision-making be taught as part of the pilot  training curriculum. ADM research, development, and  testing culminated in 1987 with the publication of six  manuals oriented to the decision-making needs of variously  rated pilots. These manuals provided multifaceted materials  designed to reduce the number of decision-related accidents.  The effectiveness of these materials was validated in  independent studies where student pilots received such  training in conjunction with the standard flying curriculum.  When tested, the pilots who had received ADM training  made fewer in-flight errors than those who had not received  ADM training. The differences were statistically significant  and ranged from about 10 to 50 percent fewer judgment  errors. In the operational environment, an operator flying  about 400,000 hours annually demonstrated a 54 percent  reduction in accident rate after using these materials for  recurrency training. History of ADM Figure 16-2. The Advisory Circular, AC60-22 Aeronautical Decision Making carries a wealth of information that the pilot  Figure 5-1.  Advisory Circular (AC) 60-22, Aeronautical Decision Making, carries a wealth of information for the pilot to learn. 5-2