I have had this issue several times after in the last two months.  After a restart or wipe the Heli won't spawn, getting server error Invalid Position: servergibs_patrolhelicopter.  The supply drops will not call in a plane either.  The cargo ship spawns in fine and has no issues.  I can spawn a heli on me but it automatically destroys it.  Can anyone point in me the right direction?  This is getting frustrating.

I recommend to log its position OnEntitySpawn()... I guess it spawns out of map from some reason.

Also do you use any event plugins (EventRandomizer, TimedEvent etc)? 

Had a problem similar to yours before. What i did was i reinstall the server and add my plugins and datas back removing any plugins that control their spawn. Adding the plugins 1 by 1 to find out which one is causing them to not spawn. Not sure about this but i think if you loaded too many plugins that control them might screw up some of it's variables or something.

What plugins are you running ?
I am using HeliControl and FancyDrop with no problems at all. I am also using InfoPanel and Inbound for notifications/announcements

I have FancyDrop and InfoPanel as well.  I believe I found the issue, it was a spawn database that was altering config files.  Removed it and it's been ok so far.