A contact in the US who moves in aviation union circles just bet me five pounds that the new FAA administrator will be one-time US ALPA president Randy Babbitt. He's apparently seen as a compromise candidate who's more acceptable to backers of rival candidates than another former ALPA president Duane Woerth. Woerth is the favoured candidate of the AFL-CIO union umbrella group but carries a lot of baggage, not all of it helpful.
Watch this space. (I didn't accept the bet.)