The 737-300 is the first of the three member second generation CFM56 powered 737 family, which also comprises the stretched 737-400 and shortened 737-500. The success of the second generation Boeing 737 family pushed sales of the mark to over 3000, a record for a commercial jetliner.
Boeing announced it was developing the 737-300 in March 1981. This new variant started off as a simple stretch over the 737-200 but Boeing decided to adopt the CFM International CFM56 high bypass turbofan (jointly developed by General Electric and SNECMA) to reduce fuel consumption and comply with the then proposed International Civil Aviation Organisation Stage 3 noise limits.
Despite the all new engines and the 2.64m (104in) fuselage stretch, the 737-300 retains 80% airframe spares commonality and shares the same ground handling equipment with the 737-200. A number of aerodynamic improvements were incorporated to further improve efficiency including modified leading edge slats and a new dorsal fin extending from the tail. Another feature was the flattened, oval shaped engine nacelles, while the nosewheel leg was extended to increase ground clearance for the new engines. Other internal changes include materials and systems improvements first developed for the 757 and 767 programs, including an early generation EFIS flightdeck (with four colour CRT screens).
The 737-300 flew for the first time on February 24 1984, while first deliveries were from November 1984. Since that time well over 1000 737-300s have been sold and it forms the backbone of many airlines' short haul fleets.