From Canadian Power Wiki
The McDonnell Douglas MD-80 is a series of twin-engine, short- to medium-range, single-aisle commercial jet airliners. It was lengthened and updated from the DC-9. This series can seat from 130 to 172 passengers depending on variant and seating configuration.
The MD-80 series was introduced into commercial service on October 10th, 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 series was followed into service in modified form by the MD-90 in 1995 and the Boeing 717 (originally MD-95) in 1999.