Using duct tape, secure your box.
Then spray paint it and allow to dry. You may need to do multiple coats.
Cut off the top of the box and set aside. You cut this off so that the child can sit in it and pretend to fly the plane. If needed, cut down the remaining sides a bit so the kid can sit comfortably/see over the edge of the box.
Using the top you cut off, draw a wing shape. You'll want to make sure you can fit two to the piece of cardboard, or be ready to cut up another box.
Cut slits into the side of the box so that you can fit the wings on either side and insert the wings into the box of the plane.
Using extra pieces of cardboard, cut out a propeller shape and a circle shape. Glue the propeller pieces onto a paper cup, and the circle piece of cardboard on top of it. If you haven't yet, paint the cup to match the cardboard.
To make the 'jet flames,' cut several strips of streamers and floral wire. Hot glue or tape the floral wire to the pieces of streamers, this will give them a bit of shape and allow them to flutter from the back of the plane.
Using a push pin or small knife, poke holes in the back of the cardboard box. Run the floral wire through the box and loop around the top, or tape down the wire to secure. Repeat until you have your desired look/amount of flames.
Make sure to have your top gun pilot inspect the plane before taking off!