There are three models in the Boeing 737 Classic generation: the 737-300, -400 and -500. Unlike the Boeing 737 Original generation, models in the Classic generation are fitted with 2 high-bypass CFM International CFM56s and not 2 low-bypass Pratt & Whitney JT8Ds. The CFM56s are wider, bigger and are more economical than the JT8Ds. Due to the success of the Boeing 737-200 Advanced, Boeing decided to keep producing the 737, but with a higher capacity and a better range. Those are the main reasons for the creation of the Classic generation. The first model in the Classic generation is the 737-300, that was launched with US Air in November 1984. The aircraft was produced between 1984 and 1999, in which time 1’113 were sold. The plane model has either 128 or 141 seats, depending on whether there are 2 or 1 classes/class in the aircraft. It can also have 149 seats, but that is maximum capacity, and can have some influences on the angle at which the pilot can fly the plane (when a plane goes up and down, the real term to use is pitch [to go up is climbing and to go down is diving, pitch is used to express the angle at which a plane moves vertically]). The 737-300 has a length of 33 meters. The second model in the Classic generation is the 737-400, that was launched in 1988 with Piedmont Airlines (an American airline based in North Carolina that was merged with US Air in 1989). It was produced between 1988 and 2000, during which 470 aircraft were sold. The seating layout is exactly the same as the 737-300 and so is the length. The third and last model is the 737-500, which was launched in 1987 with Southwest Airlines. It is smaller in length and size than the previous 2 models in the Classic generation, measuring only 31 meters. The capacity of the 737-500 is of course lower than the other models in the Classic generation, as it is not as long. The plane can have a 2 class seating layout with 108 seats or a single class seating for 132 people, with some influences on the pitch. 387 737-500s were produced. So, like the Original generation, the Classic generation was a success, as well as an enormous step technologically in aerodynamics. Thank you for reading this article. McCloud. 24th of April 2020.