The McDonnell Douglas MD-80 is a family of twin-engine, short- to medium-range, single-aisle commercial jet airliners. The MD-80 series were lengthened and updated from the DC-9. The airliner family can seat from 130 up to 172 passengers depending on variant and seating configuration.The MD-80 series was introduced into commercial service on October 10, 1980 by Swissair. The series includes the MD-81, MD-82, MD-83, MD-87, and MD-88. These all have the same fuselage length except the shortened MD-87. The MD-80 series was followed into service in modified form by the MD-90 in 1995 and the MD-95/Boeing 717 in 1999.