The U.S. Marines are trying to find out why their aviation accident rate is higher, and rising. So far this year, the marine accident rate is 4.9 (4.9 serious aviation accidents per 100,000 flight hours). This is compared to the navy rate of 1.16 and 1.15 for the air force. Last year, the marine rate was 2.75. Most of the accidents were stateside, not in combat zones. So everyone is looking at training methods and procedures. Accidents are here defined as some mishap with an aircraft that either kills someone or causes at least a million dollars of damage. Currently, each aviation accident costs over four million dollars.