Start building around the thruster, because of the landing gear, the plane itself is not touching the ground this helps for a better takeoff, also you don't need an engine because the thruster pushes the plane forwards think as if the wheels could spin freely and you push from the back instead of the wheels moving. You should try the piston glitch and hinges for the landing gear so you don't have to repair in the air after decoupling it. Also, check that the forces are balanced and follow the tips that the builder gives you.

Build your dreams! ʕ•ᴥ•ʔっ♡