Take the top left corner and bring the top edge of the paper to meet the right side of the paper. This will make a square shape folded into a half triangle at the top half of the paper. Smooth down the fold then open up the paper again.
Swivel the airplane around so the center fold is facing you. Now bring down the top wing and fold it almost all the way down, leaving about the width of a finger between the new fold and the center fold underneath. Smooth down the new creases.