The helicopter pilots don't want you to know this but the men at HQ are free. You can just take them to the CZ. I have 458 men.

I wish this happened more often, because bringing this group into the zone was fun (I get why people prefer helicopters, though). For the drivers out there, the game does register people in your bed like this and rewards you with deployment experience. As long as you drive carefully you can bring a big crew in like this.