the boeing 747-400 is a jet airliner, a variant of the boeing 747. compared to the original 747, the 747-400 features improvements such as more powerful engines, new avionics, a new interior, and a longer-span wing with winglets. the 747-400 first flew in 1988 and entered service in 1989. it was produced until 2009 in six different variants: 747-400, 747-400f, 747-400m, 747-400d, 747-400er, and 747-400erf.