There is a popular plugin: Don’s Flying AI.It may not be getting updates though. Personally I think you have to weigh up how much time it will take you to get used to 3rd-Party code, versus how much functionality or sophistication you actually need, versus how quickly it will take you to make your own purpose built system from scratch.
I use a very simple system. Its got 3 parts. The first is the movement code. It takes a point or vector and the ship moves straight to that point and hovers there for a time. The second part generates a list of target destinations to go to. This can be as crude as using a BP node to get a random point inside the bounds of the map, or it can involve a hard-coded list of strategic choke-points or key locations (observed from human player heat-zones). You can add a timeout in case the ship can’t make it there and then send it to a secondary target. The third part focuses on strategies for obstacle avoidance, or tracing against the world for level objects and other dynamic actors flying about.
You can have 100’s of these types of ships in a level doing dynamic tracing without FPS drops, so long as you keep the ship collision and mesh complexity as low as possible. You must also optimize the level collision itself (merge actors). There are lots of great threads on this topic if you invest some time (Flocking / RVO / A* pathing etc). Start by searching on Flying AI as a title keyword… BTW: You’ve been on the forums for a couple of years so you can probably answer other devs questions too occasionally. Otherwise if help is always one-way, the forums are just going to die.