It retains the 747 airframe, including the 747-300 stretched upper deck, with 6-foot (1.8 m) winglets.
Type certification was received on January 9, 1989, and it entered service with NWA on February 9, 1989. The first 747-400 was rolled out on January 26, 1988, and made its maiden flight on April 29, 1988. Northwest Airlines became the first customer with an order for 10 aircraft on October 22, 1985.
The 'Advanced Series 300' was announced at the September 1984 Farnborough Airshow, targeting a 10% cost reduction with more efficient engines and 1,000 nautical miles (1,900 km 1,200 mi) of additional range. The Boeing 747-400 is a large, long-range wide-body airliner produced by Boeing Commercial Airplanes, an advanced variant of the initial Boeing 747.
