Aircrew routinely had to maintain currency in their primary flight position, such as plane commander, co-pilot, etc. But there was a much wider set of evaluations we had to meet, called "quals." There were two major differences: these were administer to the crew as a whole, and there were a lot more of them. Some were quite involved. For example, the "TORPEX" required a crew to detect, localize, track, and attack a submarine with a Mk-46 torpedo. Since expendable submarines were in short supply, we used an unmanned submersible target within an instrumented range in Hawaii. A crew was considered "Alpha" if ALL quals had been successfully completed within a certain period (a year if memory serves).