The FAA Airman registry search is free and public record. I searched last name power, first name initial "M" and came back with 26 hits. None of them had first name Max. Lots of Michaels. No middle names of Max* either. I'm guessing he was giving you either a joke name or a nickname like Captain Sully was informally called by colleagues. He could be one of the Michaels, for example, but has gone by the nickname of Max. We'll never know unless someone stops to say hello to him on the way off to get a peek at his badge (if it's showing).....

About 20 years ago I met and got to know a USAirways A330 Captain who's first name was Lou, but he went by "Skip". Even had it on his business card and introduced himself as such.