It’s aviation’s Everest: the highest rating, the toughest to obtain and necessary to have to fly in the Part 121 airline world, and even in some portions of the Part 135 air taxi world. In reality, if you want to fly for a living, the chances are almost unity that you’ll need to hold an Airline Transport Pilot (ATP) rating to do so. Even in the corporate world, operating under Part 91, insurers want the pilots who haul mega-buck executives around to hold aviation’s Ph.D.
This is a companion discussion topic for the original entry at https://www.avweb.com/flight-safety/flight-training/the-atp-rating-expensive-training