It is not possible. Pilot NPCs currently have no function.
However, you can NPC control ships, and they will follow you, but this does not require a physical NPC. To do this, the ship you are in and the ship you want following you must be the same type of ship, and both must be any fighter, lambda, drop ship, sentinel, or delta shuttle. They must also be at the exact same location.
If you meet all those conditions, you can set the other ship to NPC controlled under your ship inventory, then "Manage Pilot Ship."