Editing Boeing 737 (section)

==== 737-300 ====
[[File:N513AU in Florida, 1991.jpg|thumb|A 737-300 with larger CFM56 turbofans, introduced by USAir on November 28, 1984. This aircraft would later crash as [[USAir Flight 427]].]]
Development began in 1979 for the 737's first major revision, which was originally introduced as the 'new generation' of the 737.{{sfn|Shaw|1999|p=7|ps=}} Boeing wanted to increase capacity and range, incorporating improvements to upgrade the aircraft to modern specifications, while also retaining commonality with previous 737 variants. In 1980, preliminary aircraft specifications of the variant, dubbed 737-300, were released at the [[Farnborough Airshow]].{{sfn|Endres|2001|p=126|ps=}} This first major upgrade series was later renamed 737 Classic. It competed primarily with the MD-80, its later derivative the [[McDonnell Douglas MD-90|MD-90]], and the newcomer [[Airbus A320 family]].

Boeing engineer Mark Gregoire led a design team, which cooperated with [[CFM International]] to select, modify and deploy a new engine and nacelle that would make the 737-300 into a viable aircraft. They chose the [[CFM International CFM56|CFM56-3B-1]] [[Bypass ratio|high-bypass]] [[turbofan]] engine to power the aircraft, which yielded significant gains in fuel economy and a reduction in noise, but also posed an engineering challenge, given the low ground clearance of the 737 and the larger diameter of the engine over the original Pratt & Whitney engines. Gregoire's team and CFM solved the problem by reducing the size of the fan (which made the engine slightly less efficient than it had been forecast to be), placing the engine ahead of the wing, and by moving engine accessories to the sides of the engine pod, giving the engine a distinctive non-circular "hamster [[Cheek pouch|pouch]]" air intake.{{sfn|Endres|2001|p=128|ps=}}<ref>Sweetman, Bill, All mouth, Air & Space, September 2014, p.14</ref> Earlier customers for the CFM56 included the U.S. Air Force with its program to re-engine KC-135 tankers.{{sfn|Garvin |1998|p=137}}

The passenger capacity of the aircraft was increased to 149 by extending the fuselage around the wing by {{Convert|2.87|m|ftin|sp=us|order=flip}}. The wing incorporated several changes for improved aerodynamics. The wingtip was extended {{Convert|9|in|cm}}, and the wingspan by {{Convert|1|ft|9|in|cm}}. The leading-edge slats and trailing-edge flaps were adjusted.{{sfn|Endres|2001|p=128|ps=}} The tailfin was redesigned, the flight deck was improved with the optional EFIS (Electronic Flight Instrumentation System), and the passenger cabin incorporated improvements similar to those developed on the [[Boeing 757]].{{sfn|Shaw|1999|p=10|ps=}} The prototype -300, the 1,001st 737 built, first flew on February 24, 1984, with pilot Jim McRoberts.{{sfn|Shaw|1999|p=10|ps=}} It and two production aircraft flew a nine-month-long certification program.{{sfn|Shaw|1999|pp=12–13|ps=}} The 737-300 retrofitted with [[Aviation Partners]]' winglets was designated the -300SP (''Special Performance''). The 737-300 was replaced by the 737-700 of the Next Generation series.