HOW DO YOU GET THE SIXTH PLANE ?

you have to complete the battle with the behemoth and then collect 15000 scrap and go to the hangar and talk to the pirate ,he sell you the plane(Gunship)

well, when playing in hero mode, a new plane appear, you need find parts of this plane on the world, i think it have 1 part in each place, like sector zero, far drop, brink..... you need go fly to find they, you find with your plane, not walking...

The 6th plane is in hero mode and on brink island you deafeat the boss robot and as you leave in the hellcat Tym is in the plane with you he describes the plane is broken into 5 pieces as you take of turn hard left and part of the plane is on a rock then fly under the main island and the 2nd part is there I can only find the first 2 pieces they are all on the brink

Well I've only found 4 the two on the brink 1 in far drop under the big pillar thing outside and 1 at the old aeropan barracks on the way toward the landing area put go right and follow the mountains to the end

I have got all six pecies 1 in brink sector zero
Fardrop and other -places

You have to find 5 engine parts that are scattered . Ther is one in each area.

You need to find five engine parts 2 on the brink, 1 on the aeropan barracks, 1 on sector zero, and 1 on Far Drop Behind the ship under the big part of the island looking thing

Note: Only accessible in 2nd playthrough
Locations:
1.Brink Island- between two large pillars holding the middle island up
2.Brink island- above a tree near the landing area at the old scientists house
3.Far drop- Under the large mountain thats held up with pillars
4.Old Aeropan barracks- find the landing zone in a valley, follow the valley along to the other end
5.Sector Zero- The northenmost pillar in the middle of the map, in one of the holes on the pillar

Hope this helps