I recall seeing Trumps name on a flight log once, it's ok to ask in order to dig and verify stuff. Pretty sure that anyone with his amount of money would be pressured into getting into this. I'd imagine he told them where to go trying to get him into it.

That having been said, if you've seen "The Sound of Freedom", I'm pretty sure (spoiler alert!) Trump was the wealthy guy (with a white hat!) that helped finance the mission to send Tim Ballard abroad to find the kid.