The Boeing 737-400 is a mid-size, narrow-body twin-engine jet airliner built by Boeing Commercial Airplanes. It is the manufacturer's largest narrow-body twinjet and features two turbo fan engines, a supercritical wing design, and a conventional tail. This 737-400 has a capacity of 168 persons and a maximum range of 4,005 km, depending on variant. The 737-400 is the definitive version and comprises the majority of 737s sold. It has a maximum take-off weight (MTOW) of 68,050 kg, a length of 36.5m, and a maximum range of 260 nautical miles. According to manufacturer specifications, the -400 can carry up to 188 passengers in a typical single class configuration. The 737-400 was available in two different door configurations; the baseline version had three standard size doors per side with a smaller emergency exit aft of the wing on each side, while the alternate version had three standard doors per side and two plug-type over-the-wing exits.