Before you ask, yes, I did put the BGl in my Scenery/World/Scenery folder. The only ideas I have about this are that I am missing the carrier's file, or that because of the location of my FSX (C:/Flight Simulator X), the file is not being found. When I start the mission my helo and all the other aircraft just sort of float 70ft over the ocean. Any thoughts?

Couple of things could be going on. Anytime you add .bgl files, you need to allow FSX to re-index your scenery files. If you were running FSX when you installed this mission, you need to restart FSX.Usually, FSX will detect when it needs to reindex, but you can force it manually by moving a scenery item up or own on the list that is displayed when you click Settings, then the Scenery Library button.