Not specifically about helicopter pilots, but I am currently writing an article on organists who fly planes for a certain American magazine. There is a considerable overlap, including several pilots for each major American airline, as well as several organists in my city and a number of luminaries (sometimes because of The War).

My only concern re your suggestion is that coordination only becomes a useful skill for organists once they've passed the beginner stage and started using the pedals relatively independently. A Trio Sonata might feel a bit like a crosswind landing, but there's a learning curve to even getting there, and limiting your search to people with extensive prior keyboard experience will help get people to this point without washing out.

I'm a pilot and organist, and incidentally know a number of other organists that are pilots. I honestly don't know that I see a particular relationship, though. I do acknowledge that I have good eye-hand coordination beyond playing the organ, but I also find the specific physical aspects of flying to be rather simple overall (only speaking of planes, no experience with helicopters).