http://dmses.dot.gov/docimages/pdf90/300465_web.pdf

Central paragraph: "The regulation's requirements for flight training on
aircraft with an MTOW of 12,500 pounds or less do not take effect until
October 20, 2004. Flight students who are enrolled in such flight training
prior to October 20, 2004, are not subject to the regulation."

That's the only comment so far from the TSA on the docket. As written, it
leaves open some questions. For example, it seems to allow you to switch
instructors during training, depending on whether you read the letter in the
narrow context of the rule. At a stretch, you could even say you are in
perpetual training from the day of your first lesson.

-- David Brooks