Tutorials
Gunship Paths
Unlike a lot of the other NPC's, helicopters and gunships use paths instead of nodes to decide where to go. To make a basic, square path that a gunship follows, you:
1) Make a large box and hollow it. Place an npc_combinegunship in the center of your room. Make the room big enough that the gunship will have plenty of room to fly around. They can go a fair bit off track when running away from rockets. Open up the properties box of the gunship, and set its 'Target path_track' to "path1"
2) Place a path_track entity towards a corner of the room, about halfway between the ground and the ceiling. Open up the properties box and set its name to "path1". Set its 'Next Stop Target' to "path2". Hold down the shift key and drag the first path_track to a different corner of the room.
Release the left mouse button before shift, and a yellow line should now connect the two points. Thats a path, but it does not form a loop, so the gunship would follow the path to the end, then stop. Change the 'Next Stop Target' of the second point to "path3", then shift-drag again to make a third point.
Repeat this until you have four points, then set the 'Next Stop Target' of the fourth point to "path1". There should now be a yellow line connecting the path_tracks, forming a square. The gunship will follow this path.
3) Whack in some lights and an info_player_start and compile. You might want to put on god mode, because the gunship will rape you pretty fast otherwise. I've noticed that if you don't fight back the gunship will sit and hover at a point, shooting at you until you shoot at it. I haven't experimented much with the settings yet, but you can.
Serever