McDonnell Douglas DC-9
The DC-9-10 first flew on February 25, 1965, and gained its type certificate on November 23, to enter service with Delta Air Lines on December 8.The DC-9 is powered by two rear-mounted Pratt & Whitney JT8D low-bypass turbofan engines under a T-tail for a cleaner wing aerodynamic.The Series 30, stretched by 15 ft (4.5 m) to seat 115 in economy, has a larger wing and more powerful engines for a higher maximum takeoff weight (MTOW); it first flew in August 1966 and entered service in February 1967.Smaller variants competed with the BAC One-Eleven, Fokker F28, and Sud Aviation Caravelle, and larger ones with the original Boeing 737.This was further developed into the third generation, the MD-90, in the early 1990s, as the body was stretched again, fitted with V2500 high-bypass turbofans, and an updated flight deck.[1] The Model 2067, a four-engined aircraft sized for medium-range routes was studied in depth, but work on it was abandoned after the proposal did not receive enough interest from airlines.In 1960, Douglas signed a two-year contract with the French aeronautics company Sud Aviation for technical cooperation; under the terms of this contract, Douglas would market and support the Sud Aviation Caravelle and produce a licensed version if sufficient orders were forthcoming from airlines.Throughout its development, Douglas had placed considerable emphasis on making the airliner as economic as possible, as well as to facilitate its future growth.[5] The adoption of the Pratt & Whitney JT8D low-bypass turbofan engine, which had already been developed for the Boeing 727, enabled Douglas to benefit from the preexisting investment.Several key refinements to the aircraft were made during flight testing, such as the replacement of the original leading-edge slat design to achieve lower drag.[12] The flight test program proceeded at a rapid pace; the initial Series 10 received airworthiness certification from the Federal Aviation Administration on November 23, 1965, permitting it to enter service with Delta Air Lines on December 8.[9] Through the DC-9, Douglas had beaten rival company Boeing and their 737 to enter the short-haul jet market, a key factor that contributed to the DC-9 becoming the best selling airliner in the world for a time.[21][22] Studies aimed at further improving DC-9 fuel efficiency, by means of retrofitted wingtips of various types, were undertaken by McDonnell Douglas, but these did not demonstrate significant benefits, especially with existing fleets shrinking.It has yet another fuselage stretch, an electronic flight instrument system (first introduced on the MD-88), and completely new International Aero V2500 high-bypass turbofan engines.The DC-9's takeoff weight was limited to 80,000 lb (36,300 kg) for a two-person flight crew by the then-Federal Aviation Agency regulations at the time.The third was the absence of engines in underslung pods, which permitted a reduction in fuselage ground clearance, making the airliner more accessible to baggage handlers and passengers.[33] The problem of deep stalling, revealed by the loss of the BAC One-Eleven prototype in 1963, was overcome through various changes, including the introduction of vortilons, small surfaces beneath the wings' leading edges used to control airflow and increase low-speed lift.A passenger/cargo version of the aircraft, with a 136-by-81-inch (3.5 by 2.1 m) side cargo door forward of the wing and a reinforced cabin floor, was certificated on March 1, 1967.Therefore, the wing design of the Series 10 featured airfoils with extremely high maximum-lift capability to obtain the low stalling speeds necessary for short-field performance.[citation needed] In 1969, a DC-9 Series 20 at Long Beach was fitted with an Elliott Flight Automation Head-up display by McDonnell Douglas and used for successful three-month-long trials with pilots from various airlines, the Federal Aviation Administration, and the US Air Force.It entered revenue service in August 1975 with Eastern Airlines and included several detail improvements, a new cabin interior, and more powerful JT8D-15 or 17 engines in the 16,000 and 16,500 lbf (71 and 73 kN) class.The thrust reverser modification was developed by Air Canada for its earlier aircraft, and adopted by McDonnell Douglas as a standard feature on the series 50.[citation needed] With the existing DC-9 fleet shrinking, modifications do not appear to be likely to occur, especially since the wing design makes retrofitting difficult.With the steps on the ventral stairs removed, it is the only airline transport class jet certified to date by the FAA for skydiving operations as of 2006.[48] This is the last and only -21 series still airworthy, and after being out of service for over a decade, it returned to the sky on May 7th, 2024[49] During the mid 1990s, Northwest Airlines was the largest operator of the type in the world, flying 180 DC-9s.[50] After its acquisition of Northwest Airlines, Delta Air Lines operated a sizable fleet of DC-9s, most of which were over 30 years old at the time.
Northwest AirlinesNarrow-bodyjet airlinerManufacturerDouglas Aircraft CompanyMcDonnell DouglasUSA Jet AirlinesAeronaves TSMEverts Air CargoDelta Air LinesMcDonnell Douglas C-9McDonnell Douglas MD-80McDonnell Douglas MD-90Boeing 717single-aisle aircraftMcDonnell Aircrafttype certificatePratt & Whitney JT8DturbofanT-tailairstairsmaximum takeoff weightBAC One-ElevenFokker F28Sud Aviation CaravelleBoeing 737Rolls-Royce BR715Douglas AircraftjetlinerSud Aviationlicensed versionBoeing 727trijetshared-risk production arrangementsde Havilland Canadaleading-edge slatairworthiness certificationFederal Aviation AdministrationBoeingEastern Air LinesLong Beach, CaliforniaAirbus A320sBoeing 737sfuel efficiency replacing enginesMD-80 seriesMD-90 serieslanding gearelectronic flight instrument systemInternational Aero V2500BMW/Rolls-Royce BR715Comac ARJ21Federal Aviation Agencyforeign object damagevortilonsRepublic Airlinesnautical milesScandinavian AirlinesElliott Flight AutomationHead-up displayUS Air ForceScandinavian Airlines SystemAir CanadaAir Canada Flight 797Eastern Airlinesleading edge slatsKrueger flapsAfrican Express AirwaysAirbus A320Embraer E-JetsAirbus A220Perris, Californiaaviation accidents and incidentshull-lossesWest Coast Airlines Flight 956TWA Flight 553Concord TownshipUrbana, Ohiomid-air collisionBeechcraft Baronair traffic controlOzark Air Lines Flight 965Cessna 150FLambert FieldViasa Flight 742Maracaibo, VenezuelaAllegheny Airlines Flight 853Piper PA-28 CherokeeFairland, IndianaDominicana de Aviacióncrashed after taking offSanto DomingoTeo CruzOverseas National AirwaysALM Flight 980ditchedNew York'sJohn F. Kennedy International AirportPrincess Juliana International AirportSaint MaartenSaint Croix, U.S. Virgin IslandsSouthern Airways Flight 932Tri-State AirportMarshall UniversityHughes Airwest Flight 706Turkish AirlinesTurkeyJAT Flight 367StockholmBelgradeVesna VulovićNorth Central Airlinescollided during its takeoff rollConvair CV-880O'Hare International AirportChicago, Illinoiswere written offIberiaPalma de MallorcaLondoncollided in mid-airSpantaxConvair 990MadridDelta Air Lines Flight 723seawall