Abstract: The present invention is a system and method for modifying a passenger aircraft and converting it for use as a cargo aircraft, wherein the steps include removing all structures that were previously put into the aircraft to accommodate passengers including walls, storage, and seating, wherein the seat tracks are left in the floor to function as secure attachment points, moving pallet sections into the aircraft that can fit through the existing doorways, and assembling the pallet sections together to create pallet assemblies, wherein the pallet assemblies function as a bridging system upon which cargo loads may be disposed without causing damage to the existing unreinforced floor of the aircraft, wherein each of the pallet assemblies is connected to the existing seat tracks in the floor in order to secure the pallet assemblies to the aircraft frame.