Something that isn't mentioned about FAA instructors: The FAA monitors instructor's student pass rates for Part 61 training. If too many candidates recommended by an instructor fail to pass at 1st attempt the instructor can lose his or her instructor certificate, be required to get remedial training, or be required to be retested. This takes the place of an authorised/licenced/certificated/whatever school's pass rate monitoring eg a Part 141 school, or a commercial or higher school in Oz