 Peace brought these airmen, who often possessed no other skills, back to a country where immense stores of surplus military aircraft were being sold at discount rates to former servicemen.Under the 1938 legislation of the Civil Aviation Authority, the federal agency responsible for regulating civil aviation until 1940, all air carriers providing scheduled air service across states required an official certificate to operate, the Certificate of Public Convenience and Necessity.The certificate demanded compliance with economic as well as safety standards, which meant all certificated companies were subject to the CAA’s stringent control over fares, routes, and business practices.