The Boeing 767 is a mid- to large-size, long-range, wide-body twin-engine jet airliner built by Boeing Commercial Airplanes. It was launched as the 7X7 program on July 14, 1978, and the prototype first flew on September 26, 1981. The 767 was Boeings first wide-body twinjet and was designed with fuel efficiency in mind, aiming for an operating cost saving of between 20% and 30% compared to previous aircraft. The 767 has seating capacity for 181 to 375 persons and a design range of 3,850 to 6,385 nautical miles, depending on the variant. The 767 has been produced in three fuselage lengths: the original 767-200, followed by the 767-300, and the 767-400ER. The 767 has been used in a number of military and government applications, with responsibilities ranging from airborne surveillance and refueling to cargo and VIP transport.