I stand corrected on the TSA issue but you still can't enroll in a flight school for a training course with the visa waiver. Bottom line you notice how unsure people are about this process and you don't want to end up with an immigration official who interprets the rules differently and then denies you entry. Its a pain in the A
and we are doing a good job killing the industry but when it comes to immigration error on caution...get the student visa and if that was too much or you didnt need it you can still do the training and don't have to worry.