When Scandinavian Airlines Systems (SAS) made a request for a version of the DC-9 with improved short field performance, Douglas responded with the DC-9-20. The same length as the DC-9-10, the DC-9-20 was equipped with uprated JT8D engines as well as revised wings equipped with leading edge slats for enhanced lift. The first flight of the DC-9-20 was on 18 September 1968. Type certified on 25 November 1968, the first DC-9-21 delivered to SAS arrived on 11 December 1968. SAS then put their new 90 pax short-field DC-9s into service beginning on 27 January 1969. Production of the DC-9-20 ended when the SAS order for ten jets was completed on 1 May 1969. A total of six carriers used the DC-9-20 series jets.
Stretching the Nine
The next variant of the DC-9 was the DC-9-30. Built in part to compete with Boeing’s new 737, the 30 was just shy of 15 feet longer than the 10/20 at 119 feet 3.5 inches and had another 4 feet of wingspan. The 30 also incorporated the full span leading edge slats from the 20 with an increase in chord ahead of the front spar and uprated JT8Ds. Maximum takeoff weight was up to 108,000 pounds. Built in seven variants including dedicated cargo, convertible cargo/passenger, and passenger use only, the -30 series flew for the first time on 1 August 1966 and went into service with Eastern Airlines in December of 1966. Douglas produced a total of 662 of the 115 pax -30 models which were used by more than 100 carriers.
Really Stretching the Nine
The DC-9-40 series was six feet longer than the -30 at 125 feet 7 inches, equating to another ten passengers in the cabin. The -40 maximum takeoff weight was up to 114,000 pounds thanks to uprated JT8D engines and the six foot stretch in length. Like all DC-9 series jetliners, the inside cabin width was 122.4 inches- just a hair over ten feet. The DC-90-40 flew for the first time on 28 November 1967 and went into service with SAS in March of 1968. 12 carriers utilized the DC-9-40 series including freight carriers like DHL and Airborne. Douglas built 71 DC-9-40 series aircraft.
The Nine Stretched to the Max
The DC-9-50 was another 8 feet longer than the DC-9-40 at 133 feet 7 inches and was therefore capable of carrying 139 pax. The cabin was redesigned to look more stylish but was no wider than the previous models. First class seating was four across with two seats on each side of the aisle. Coach seating was configured for two seats on the port side and three on the starboard side. The -50 also featured uprated JT8D engines producing up to 32,000 pounds of thrust combined. The engines featured revised thrust reversers and the aircraft had strakes mounted forward under the flight deck as well as a spray deflector for the nose wheel. The -50 flew for the first time in late 1974 and first entered service with Eastern Airlines in August of 1975. The 96 DC-9-50s built were operated by more than 25 carriers.
Mergers and Military Use
Douglas merged with McDonnell to form McDonnell-Douglas in 1967. Between then they manufactured a total of 976 DC-9 aircraft during a production run from 1965 to 1982. In military use the DC-9 was designated C-9 and was used by the US Air Force (as the C-9A Nightingale) to evacuate sick/wounded personnel. The US Navy and Marine Corps operated C-9B Skytrain IIs as passenger carriers. Three Air Force C-9As were converted for use as VIP transports and designated VC-9C. A total of 47 DC-9s found their way into United States military service as C-9s.
Dwindling Supplies and One Kind of End
In 1996 there were still more than 880 DC-9s in service around the world. But the carriers pulled the plugs on their DC-9 fleets quickly enough that by January 2014 Delta was ready to retire their last remaining DC-9s. They did so on 6 January 2014, when flight 2014 arrived at Atlanta from Minneapolis/St. Paul. That was the last scheduled DC-9 series jetliner flight by a major US carrier. There are still a few DC-9s in service but finding them is growing increasingly difficult. Of course McDonnell Douglas developed the DC-9 into the MD-80 and MD-90 series of super-stretched DC-9s. When McDonnell Douglas merged with Boeing in 1997 the MD-95 was renamed the Boeing 717. But that’s another story. However, including the 1,307 “Mad Dogs” and the 155 Boeing 717s, the DC-9 family of jetliners totaled some 2438 aircraft.
Some of the nicknames the DC-9 series picked up over the years are Greasy Nine, Diesel Nine, Mini Me, Pocket Rocket (-10 series), DC-3GT, DC-9 Sport (-20 series), Dirty Thirty (-30 series), and T-Jet.
In 2006 one of the largest drug seizures ever involved a DC-9-15. The jetliner was smuggling 5.5 tons of cocaine (in 128 identical black suitcases) from Caracas in Venezuela into Cuidad del Carmen in Mexico when the aircraft and its highly illegal cargo were seized by Mexican authorities. The bust was the highlight of a DEA operation dubbed Operation All Inclusive.
The We Are Marshall tragedy occurred on 14 November 1970. A DC-9-31 (N97S) operating as Southern Airways Flight 932 crashed into a hill near the Tri-State Airport in Huntington, West Virginia. All 75 souls on board the aircraft perished in the crash, consisting of 37 members of the Marshall University Thundering Herd football team, eight members of the coaching staff, 25 boosters, and 5 crew members.
As of 2018 a former SAS DC-9-21 was being utilized as a skydiving jump platform out of Perris Valley Airport in Perris, California. This aircraft had a modified rear air stair with the steps removed. As far as we know this is the only airline transport-class jet certified by the FAA for skydiving operations. Does anybody know if it’s still in use?
On 26 January 1972 DC-9-32 (YU-AHT) operating as JAT flight 367 enroute from Stockholm, Sweden to Belgrade, Yugoslavia, was destroyed in flight by a bomb placed on board. 23 passengers and four crew members perished in the explosion, but there was a survivor: Flight attendant Vesna Vulović, who holds the world record for the longest fall without a parachute when she fell some 33,000 feet inside the tail section of the airplane and survived.