"Northrop's initial NATF concept was based on the Air Force's YF-23 with the diamond wing and butterfly tails. since the length of the HSF was 66 ft 6 in long, and the eventual PAV YF-23 was 67 ft 4.8 in long, NATF needed to be shortened. One of the major requirements for the Navy was that the aircraft could not be longer than the current F-14 Tomcat, which was 62 ft 8.5 in long, with a swept wingspan of 38 ft. Keeping the proposed vehicle at or under the same deck footprint, or spotting factor, as the Tomcat was driven by the need to facilitate on-deck handling and aircraft placement, maintain flight deck elevator capacity and carriage, and allow for satisfactory below deck storage and maintenance work"