I have the plugin set so 2 ch47s arrive at once... They do travel around the map but never drop a lockable crate.  I have not changed any of the crate spawning locations 

same for me, tested with callch47 or callch47 pos, he coming without drop and left the map...

I'm not sure what exactly may be causing this issue, but I will take a look into it and see if it is at all related to HeliControl.