Boeing announced the 747-500X and 600X at the 1996 Farnborough Airshow. The proposed models would have combined the 747's fuselage with a new 251 ft span wing derived from the 777. Other changes included adding more powerful engines and increasing the number of tires from two to four on the nose landing gear and from 16 to 20 on the main landing gear. The 747-500X concept featured an increased fuselage length of 18 ft to 250 ft long, and the aircraft was to carry 462 passengers over a range up to 8,700 nautical miles. The 747-600X concept featured a greater stretch to 279 ft with seating for 548 passengers and a range of up to 7,700 nmi.