During the late 1980s Boeing developed the 747-400, with the same fuselage length and extended upper deck as the 747-300, but with a larger wingspan, winglets, a highly modernised digital flight deck, higher weights and a lower fuel consumption thanks to improved engines. The 747-400 made its maiden flight on 29 April 1988. It is also available in a 'short-bulge' cargo version (747-400F)and as a combi (747-400M). The 747-400D (Domestic) for short-range flights doesn't have winglets. The 747-400ER is an improved extended range version, of which also a freighter variant exists, the 747-400ERF.