nerd2009

.....and a DC9 configured with a first class generates more revenue than any arr jay.......

Series 30: Fuselage of the Series 30 DC-9, actually second developed, is nearly 15 feet longer than the Series 10, at 119.3 feet (36.3 m), providing seats for up to 115 passengers and cargo space to 895 cubic feet (25.3 m3). Series 30 wingspan was increased to 93.3 feet (28.4 m), and a high-lift wing system of leading edge slats gives the Series 30 excellent short-field performance. The first of the type began airline service in February 1967.
Most of the Series 30s are powered by either JT8D-7 or JT8D-9 engines. Others are equipped with JT8D-11 or the JT8D-15, with 15,500 pounds of thrust. The Series 30 is the most widely used member of the DC-9 family, accounting for approximately 60 percent of the entire fleet.
Series 40: To again meet airline demands for a DC-9 with more capacity, the Series 40 was developed with a fuselage length of 125.6 feet (38.3 m). Seating is available for up to 125 passengers, 10 more than the popular Series 30s. Below-floor cargo space totals 1,019 cubic feet (28.8 m3). The Series 40 uses the same wing as the Series 30. Series 40 engines are JT8D-9s, JT8D-11s or JT8D-15s. The model entered service in March 1968.
Series 50: The fifth and largest DC-9 version is extended to 133.6 feet (40.7 m) long, permitting installation of five more rows of seats than the Series 30. Maximum passenger capacity is up to 139, with cargo capacity increased similarly. Wingspan is the same as for the Series 30. Engines are either JT8D-15s or JT8D-17s, which are rated at 16,000 pounds. Airline operations with the Series 50 began in August 1975.