The airline transport pilot (ATP) is the most advanced pilot certificate one can obtain, and it’s necessary for those who want to fly commercial airliners for a living. All commercial airlines now require a pilot applicant to have an ATP certificate. To become eligible for an ATP certificate, a pilot must have logged at least 1,500 hours, be at least 23 years old, and A restricted ATP with lower requirements is available for some pilots, like military pilots and students graduating from approved universities.