McDonnell Douglas MD-81

The McDonnell Douglas MD-81 launched the MD-80 series in 1980 as a modernized evolution of the DC-9-50, featuring a 4.36-meter fuselage stretch to 45.06 meters and seating 155-172 passengers. The MD-81 introduced more powerful and efficient Pratt & Whitney JT8D-209 turbofans producing 82 kN (18,500 lbf) thrust each, offering improved fuel economy and quieter operations compared to earlier DC-9 variants. The redesigned wing incorporated advanced aerodynamics and increased fuel capacity, extending range to 2,897 km (1,570 NM). Swissair and Austrian Airlines launched service in October 1980. The MD-81 featured an upgraded flight deck with electronic flight instruments and improved systems, while maintaining commonality with DC-9 cockpit layouts for easy crew transition. Later production MD-81s received even more powerful JT8D-217 and -219 engines. The variant proved immensely popular with US carriers including American Airlines, which operated over 260 examples. The MD-81's reliability, capacity, and economics made it a backbone aircraft for domestic trunk routes throughout the 1980s-2000s. A total of 132 MD-81s were built.