Once meeting the requirements, the training lasts for two years and includes the following during the first year private pilot instrument, commercial single engine commercial, multi engine certified flight instructor, certified flight instructor instrument and multi engine flight instructor ratings. During the second year, they build experience in time by flight instructing or flying for a 135 operation. The entire second year is required due to the FAA rules regarding flying for an air carrier. Under an airline transport pilot license, all pilots must hold 1500 qualifying flight hours