Is there a trick to get them to show up, or am I just really unlucky? I'm rank 305 and have yet to find my first, and I'm kind of getting impatient waiting for one to pop up.

Non-Player Kills 2825

try doing the "Tracking the Contacts" mission and see if you can get it.

2825 NPC kills at rank 305 and hoping trying for ballistae all i can suggest is get more NPC slots and go round farming them before you see flamehawks

Tracking the Contacts is already done. Ironically, 10 minutes after I posted this, I found my first ballistae . 3 more to go.

Don't feel bad Bender, a legion-mate of mine sat on one ballistae for months while I was scrapping one about every week. Luck of the draw I suppose....

There should be a max rank for those. Getting tired of getting those instead of something actually useful. That or do a check and see if the ship has 4x equipped.

I did start to like them eventually, pretty good experience and CTP, but I'm nearly positive they're gone now, by rank 700. I feel like they might even be gone by 600 or 650, but I can't remember that well.