Amateur Radio

It’s a great algorithm called spaced repetition. I use the method so much I discovered Anki (and its parent site Anki Web) to do a ton of university studies. There’s a small learning curve, but once you get it, you can make all sorts of flash cards with fine grain detail for spaced repetition.

As for the FAA, once you are past PPL, Sheppard Air is pretty much the golden standard, only there is no space repetition in their system.