The Boeing 737-400 is a twin-engine short-to-medium-range narrowbody airliner. The 737-400 belongs to the family of over 1,500 aircraft, which translates into well-established infrastructure and high availability of economical spare parts, experienced technical crews and aircrews. Boeing rolled out the first 737-400 in 1988. Derived from the successful, well proven B737-300, the converted B737-400, by similar design, features all the advantages that the current operators appreciate: low operating empty weight, low fuel consumption due to smooth aerodynamic design, reliable and ensuring system, interchangeability of the new conversion parts due to the use of a pre-fabricated surround structure, pre-assembled kit of parts and wiring, which also minimizes conversion down time.
To handle the extra weight of the longer airframe, the subsequent increase to passenger loads, Boeing outfitted the 737-400 with upgraded CFM International CFM56-3B2/3C-1 turbofan engines. As a result of these more powerful engines, Boeing 737-400 manages some respectable numbers while maintaining the high level of fuel economy expected from an airliner in its class: range – up to 2,060 nmi (3,820 km); cruising speed – 432 knots (800 km/hour); maximum cruising altitude – 37,000 feet (11,278 m); takeoff distance – 8,690 ft (2,649 m).
B737-400 is suitable for commercial passenger and cargo transportation.