The most common airliners are the narrow-body aircraft, or single-aisles. The earliest jet airliner were narrowbodies, and today single-aisle aircraft make up the bulk of most major airlines' fleets. | The most common airliners are the narrow-body aircraft, or single-aisles. The earliest jet airliner were narrowbodies, and today single-aisle aircraft make up the bulk of most major airlines' fleets. |