Stretched by 10 feet (3.0 m), the 737-400 entered service in October 1988 with Piedmont Airlines. The 737-400 was launched in 1985 to fill the gap between the 737-300 and the 757-200.

By far, the most successful model was the 737-300, with deliveries totaling 1,113 aircraft (the 737-400 and -500 reached 486 and 389 deliveries, respectively). Major operators included US carriers, small national airlines, and charter carriers.

The Boeing 737-400 Is a remarkable aircraft and was one of the great innovations of Boeing, increasing capacity yet keeping a relatively small and economic size. Announced in 1986, it is a twin-engine, short to medium range aircraft that has a capacity of 189 passengers.

The Boeing 737-400 is a twin-engined short-to-medium-range narrowbody airliner with a capacity of maximum 189 passengers produced by the American manufacturer Boeing Commercial Airplanes.

Short to medium range airliner. Boeing announced it was developing a new higher capacity version of the fast selling 737-300 in June 1986. The new aeroplane, the 737-400, was developed as a 150 seat class 727 replacement.

Performance: Higher ceiling 37,000ft; Higher MTOW; 20% lower fuel burn than -200. Engines: High bypass (5:1), 18,500-23,500lb, CFM56-3. Fuselage: 44in fwd body extension, 60in aft body extension. Wings: Span increased by 11in wingtip extensions; Modified slat aerofoil, flipper flaps & flap track farings. Increased fuel capacity to 16,200kg.

The 737-300/-400/-500 Offers Flexibility to Meet Market Demands *Maximum range at full passenger payload 717-200 MD81 737-400 737-300 737-500 MD82 MD90-30 MD83/88 737-600 737-700 MD90-50 MD87 A319 A320 A321 737-800 757-300 757-200

The first Model 737-400 flew on 19 February 1988 and first deliveries to Piedmont Airlines took place in October that year. Because it was able to fly non-stop across the United States, this model became very popular with American operators.

The Boeing 737-400 is a twin-engined short-to-medium-range narrowbody airliner with a capacity of a maximum of 188 passengers produced by the American manufacturer Boeing Commercial Airplanes. The Boeing 737-400 is together with the 737-300 and the 737-500 member of the Classic-737-Family.

Boeing 737-400 is a twinjet short-to-medium-range narrow-body airliner with a maximum capacity of 188 passengers. Together with 737-300 and 737-500 models, the 737-400 is a member of the 737 “Classic”