In advance: Make cookie planes. Prepare and roll out dough. Use pattern to cut out planes. Bake and cool.
Cover cookies with thinned royal icing. Let dry overnight on waxed paper-covered boards. Using full-strength icing, pipe tip 2 body and steering wheel; let dry. Overpipe tip 2 arm and hand; position icing decoration in wet icing. Pipe stripes with tips 1 and 3. Using tip 2, pipe dot and bead propeller; outline oval wing and 2 tail fins. Fill in wing and fins with thinned icing. Let dry.
* Combine Royal Blue with Sky Blue for blue shown.