Even if you are converting from a foreign ATPL to an FAA ATP, you still have to take the FAA ATP knowledge exam. FAA knowledge tests only are valid for 24 months. If you don't meet the requirements for the ATP and take the practical test within the 24 month window, you have to retake the ATP knowledge test. No sense in trying to get a "frozen" FAA ATP. Also, the FAA ATP exams don't count for the IR and CPL like they do under EASA.
Last edited by zondaracer; 28th Sep 2013 at 14:48.