" 7x7 " designations. Fore more information click on the link below.↓ → http://en.wikipedia.org/wiki/Boeing_707 Boeing 717    The Boeing 717 is a twin-engine, single-aisle jet airliner , developed for the 100-seat market. The airliner was designed and marketed by McDonnell Douglas as the MD-95 , a third-generation derivative of the DC-9