Airplane parts, namely, structural cargo-storage-area components of airplanes, cargo conversion kits for airplanes comprised of structural cargo-storage-area components to modify the configuration of cargo storage space, custom airplane control modules used to mechanically control aircraft propulsion systems, aerodynamic wings for airplanes, and airflow modification devices and systems, namely, aerodynamic fairings, wing extensions, winglets, spoilers, air brakes, flaps, other structural parts in the nature of flight control surfaces, and combinations thereof