The Boeing 737-800 is a narrow-body airliner that was developed by the Boeing Commercial Airplanes (BCA) division of Boeing. It is part of the 737 Next Generation (NG) family of aircraft, which includes the 737-600, 737-700, 737-800, and 737-900 models. The 737-800 was developed as a replacement for the 737-400, which had been in service since the 1980s. Development of the 737-800 began in the late 1980s, with the goal of improving on the performance of the 737-400 while retaining the commonality of the 737 family. Boeing wanted to create an aircraft that was more fuel-efficient and had a longer range than the 737-400, while also being able to carry more passengers. One of the major changes that Boeing made in the development of the 737-800 was the introduction of a new wing design. The new wing had a greater span than the previous 737 models, which allowed for increased fuel capacity and improved fuel efficiency. The wing also featured new winglets, which improved the aircraft's performance by reducing drag. Another major change in the development of the 737-800 was the introduction of a new, more advanced avionics suite. This suite included a new flight management system (FMS), which allowed for more precise navigation and better fuel management. The avionics suite also included a new digital weather radar system, which improved the aircraft's ability to detect and avoid severe weather. Boeing also made changes to the aircraft's interior in the development of the 737-800. The cabin was redesigned to improve passenger comfort, with features such as larger overhead bins and improved ventilation systems. The aircraft's galley was also redesigned to make it more efficient and easier for flight attendants to use. The development of the 737-800 was not without its challenges. One of the major challenges that Boeing faced was the need to balance the improvements in performance and efficiency with the need to retain the commonality of the 737 family. Boeing wanted the 737-800 to be able to use the same engines, systems, and components as the other 737 models, in order to simplify maintenance and reduce costs for airlines. To achieve this goal, Boeing made a number of design choices in the development of the 737800. For example, the aircraft's fuselage was kept the same length as the 737-400, which allowed it to use the same doors and windows. The landing gear was also kept the same, which allowed the aircraft to use the same ground handling equipment as other 737 models. The first 737-800 prototype made its first flight on July 31, 1997. The aircraft was powered by two CFM56-7B engines, which were also used on the 737-600 and 737-700 models. The aircraft underwent a comprehensive testing program, which included flight testing in a variety of conditions and testing of the aircraft's systems and components. The 737-800 received its type certificate from the Federal Aviation Administration (FAA) in March 1998. The first delivery of the aircraft was made to Hapag-Lloyd Flug, a German airline, in April 1998. Since then, the 737-800 has become one of the most popular aircraft in the world, with more than 5,000 units sold to date. One of the factors that has contributed to the success of the 737-800 is its versatility. The aircraft is capable of operating in a wide range of conditions and environments, from short-haul flights to long-haul routes.