Can you complete all FAA written exams prior to flight training PPL, IR, CPL?
You sure can and in fact we highly recommend it. Check out this link: https://atpflightschool.com/faqs/acpp-prep-written-knowledge-tests.html
Do you need to enroll with atp to take these tests? It talks about getting a sign off from a ground instructor
You do not need to enroll with ATP to take the written exams. They are, however, included with your tuition once you do enroll with us. The sign-off you’re referring to is known as an endorsement. You can receive an endorsement from a CFI after you provide evidence that you have sufficiently studied and are well-prepared for the written exam you’re about to take. Please keep in mind that while you can take the written exams well in advance of your training, the scores are only valid for two years.
You do not necessarily need to enroll with ATP, but yes, you will need a sign off from an instructor. ATP is only able to provide that to students who have enrolled in their program. Your other option would be to find another CFI who is able to sign you off.
Most of the company’s (Sporty’s, Sheppard Air, Gleim etc) will provide you with an endorsement to take the Written exams. They require you to send them a number of practice tests you’ve taken with a min score of 90%. Keep in mind the Written tests expire in 2 years so I wouldn’t take them too early if you haven’t started your training yet.