Aviation safety is a term encompassing the theory, investigation, and categorization of flight failures, and the prevention of such failures through regulation, education, and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.
During the 1920s, the first laws were passed in the USA to regulate civil aviation. Of particular significance was the Air Commerce Act (1926) which required pilots and aircraft to be examined and licensed, for accidents to be properly investigated, and for the establishment of safety rules and navigation aids, under the Aeronautics Branch of the United States Department of Commerce.
Despite this, in 1926 and 1927 there were a total of 24 fatal commercial airline crashes, a further 16 in 1928, and 51 in 1929 (killing 61 people), which remains the worst year on record at an accident rate of about 1 for every 1,000,000 miles (1,600,000 km) flown. Based on the current numbers flying, this would equate to 7,000 fatal incidents per year.
The fatal incident rate has declined steadily ever since, and since 1997 the number of fatal air accidents has been no more than 1 for every 2,000,000,000 person-miles flown (e.g., 100 people flying a plane for 1,000 miles (1,600 km) counts as 100,000 person-miles, making it comparable with methods of transportation with different numbers of passengers, such as one person driving an automobile for 100,000 miles (160,000 km), which is also 100,000 person-miles), and thus one of the safest modes of transportation when measured by distance traveled.
The World Bank has published the reliable data of the frequency of passengers carried by Air Transport in the Year 2012 obtained from the International Civil Aviation Organization (ICAO). The United States of America has the largest number of Commercial Air Transport Passengers. 756,617,000 cf. China the next largest with 318,475,924. The United States had an International Flight frequency of 9,560,451 in 2012. The Civil Aviation Authority, JAR and EASA have published that there is a fatal accident ratio of one per million flights. The main cause is Pilot in Command error.