ATP

The ATP is the top pilot certificate issued by the FAA. You need at least 1,500 total flight hours and it is a requirement to serve as captain at a commercial airline. The written, oral, and practical test are all substantially harder than the commercial certificate.

When you see ATP in an instructor's credentials, they have at least 1,500 hours and have passed the FAA's most demanding practical test. Many ATP-rated instructors have airline or charter backgrounds, which adds real context if you are training toward a professional flying career.