McDonnell Douglas DC-9

DC-9
A New York Air DC-9-32, 1983
Role Airliner
Manufacturer Douglas Aircraft
McDonnell Douglas
First flight February 25, 1965
Introduction December 8, 1965 with Delta Air Lines
Status In service
Primary users Delta Air Lines
ABX Air
Aserca Airlines
Produced 1965-1982
Number built 976
Unit cost US$41.5 to $48.5 million
Variants McDonnell Douglas C-9
McDonnell Douglas MD-80
McDonnell Douglas MD-90
Boeing 717

The McDonnell Douglas DC-9 (initially known as the Douglas DC-9) is a twin-engine, single-aisle jet airliner. It was first manufactured in 1965 with its maiden flight later that year. The DC-9 was designed for frequent, short flights. The final DC-9 was delivered in October 1982.

The DC-9 was followed in subsequent modified forms by the MD-80, MD-90 and Boeing 717. With the final two deliveries of the 717 in 2006, production of the DC-9/MD-80/90/717 aircraft family ceased after 41 years and nearly 2,500 units built.

Contents

Design and development

During the 1950s, Douglas Aircraft began studying a short-medium range airliner to complement its higher capacity, long range DC-8. A medium range, four-engine design was studied, but it did not receive enough interest from airlines and was abandoned. Then in 1960, Douglas signed a two-year contract with Sud Aviation for technical cooperation. As part of the agreement Douglas would help market and support the Sud Aviation Caravelle along with license-production of an American version if orders were high enough. However, no orders were received and Douglas returned to its design studies after the two years.[1]

In 1962, early design studies were underway. The first version seated 63 passengers and had a gross weight of 69,000 lb (31,300 kg). This design was changed into what would be initial DC-9 variant.[1] Douglas officially gave approval to produce the DC-9 on April 8, 1963.[1] Unlike the competing but slightly larger Boeing 727 trijet, which used as many 707 components as possible, the DC-9 was an all-new design. The DC-9 features two rear fuselage-mounted Pratt & Whitney JT8D turbofan engines, relatively small, efficient wings, and a T-tail.[2] The DC-9's maximum takeoff weight was limited to 80,000 lb (36,300 kg) for a two-person flight crew by Federal Aviation Agency regulations at the time.[1] DC-9 aircraft have 5 seats across for economy seating. The airplane seats 80 to 135 passengers depending on version and seating arrangement. (Note: DC stands for Douglas Commercial.[3])

NWA DC-9 T-tail at Regina International Airport.

The DC-9 was designed for short to medium routes, often to smaller airports with shorter runways and less ground infrastructure than the major airports being served by larger designs like the 707 and DC-8. Consequently, accessibility and short field characteristics were called for. The tail mounted engine design facilitated a clean wing designs without engine pods, which had numerous advantages. First, flaps and slats could run the entire span of the wing, unimpeded by pods on the leading edge and engine blast concerns on the trailing edge. This simplified the design, improved airflow at low speeds and enabled lower takeoff and approach speeds, thus lowering field length requirements and keeping wing structures light. The second advantage of the tail-mounted engines was the reduction in foreign object damage from ingested debris from runways and aprons. Third, the absence of engines in underslung pods provided a reduction in ground clearance, making the aircraft more accessible to baggage handlers and passengers. Turnarounds were simplified by built-in airstairs, including one in the tail, which shortened boarding and deplaning times.

The first DC-9, a production ship, flew in February 1965. The second DC-9 flew a few weeks later and entered service with Delta Air Lines in late 1965.[2] The initial Series 10 would be followed by the improved -20, -30, and -40 variants. The final DC-9 series was the -50, which first flew in 1974.[2]

The DC-9 was a commercial success with 976 built when the production ended in 1982.[2] The DC-9 is one of the longest lasting aircraft in operation. Its reputation for reliability and efficiency drove strong sales of its successors well into the 21st century. The DC-9 family is one of the most successful jet airliners with a total of over 2,400 units produced; it ranks third behind the second place Airbus A320 family with over 4,000 produced, and the first place Boeing 737 with over 6,000 produced.

A Cebu Pacific DC-9 in 2006

Studies aimed at further improving DC-9 fuel efficiency, by means of retrofitted wingtips of various types, were undertaken by McDonnell Douglas. However these did not succeed in demonstrating significant benefits, especially with existing fleets shrinking. The wing design makes retrofitting difficult.[4]

Legacy

The DC-9 was followed by the introduction of the MD-80 series in 1980. The MD-80 series was originally called DC-9-80 series. It was a lengthened DC-9-50 with a higher maximum takeoff weight (MTOW), a larger wing, new main landing gear, and higher fuel capacity. The MD-80 series features a number of variants of the Pratt & Whitney JT8D turbofan engine having higher thrust ratings than those available on the DC-9.

The MD-80 series was further developed into the McDonnell Douglas MD-90 in the early 1990s. It has yet another fuselage stretch, a glass cockpit (first introduced on the MD-88) and completely new International Aero V2500 high-bypass turbofan engines. In comparison to the very successful MD-80, relatively few MD-90 examples were built.

The final variant of the DC-9 family was the MD-95, which was renamed the Boeing 717-200 after McDonnell Douglas's merger with Boeing in 1997 and before aircraft deliveries began. The fuselage length and wing are highly similar to those found on DC-9-30 aircraft, but much use was made of lighter, modern materials. Power is supplied by two BMW/Rolls-Royce BR715 high bypass turbofan engines.

Variants

DC-9-40 flight deck.
Ex-Spirit Airlines DC-9-30 Firebird II, highly modified as a surveillance aircraft for the U.S. Navy, based at Mojave Airport.

Series 10

The original DC-9 (later designated the Series 10) and was the smallest DC-9 series. The -10 was 104.4 ft (31.8 m) long and had a maximum weight of 82,000 lb (37,000 kg). The Series 10 was similar in size and configuration to the BAC One-Eleven and featured a T-tail and rear mounted engines. Power was a pair of 12,500 lbf (56 kN) Pratt & Whitney JT8D-5 or 14,000 lbf (62 kN) JT8D-7 engines. A total of 137 were built. Models -11, -12, -13, -14, -15, -15F and -15RC were produced. Delta Air Lines was the initial operator.

Subvariants

The Series 10 was produced in two main subvariants, the Series 14 and 15, although of the first four aircraft, three were built as Series 11s and one as Series 12. These were later converted to Series 14 standard. No Series 13 was produced. A passenger/cargo version of the aircraft with a 136 x 81 in side cargo door forward of the wing and a reinforced cabin floor, was certificated in March 1, 1967. Cargo versions included the Series 15MC (Minimum Change) with folding seats which can be carried at the rear of the aircraft, and the Series 15RC (Rapid Change) with seats removable on pallets. These differences disappeared over the years as new interiors have been installed.[5][6]

Dimensions

The Series 10 has an overall length of 104.4 feet (31.82 m), a fuselage length of 92.1 feet (28.07 m), a passenger cabin length of 60 feet (18.29 m), and a wingspan of 89.4 feet (27.25 m).

Powerplant

The DC-9 Series 10 was offered with the 14,000 lb thrust JT8D-1 and JT8D-7.[5][6]

APU

All versions of the DC-9 are equipped with an AlliedSignal (Garrett) GTCP85 APU as standard which is located in the aft fuselage.[5][6]

Performance

The Series 14 was originally certificated at an MTOW of 85,700 lb but subsequent options offer increases to 86,300 and 90,700 lb. The aircraft's MLW in all cases is 81,700 lb. The Series 14 has a fuel capacity of 3,693 US gallons (with the 907 US gal centre section fuel). The Series 15, certificated on January 21, 1966, is physically identical to the Series 14 but has the increased MTOW of 90,700 lb. Typical range with 50 passengers and baggage is 950 nm, increasing to 1,278 nm at long range cruise. Range with maximum payload is 600 nm, increasing to 1,450 nm with full fuel.[5][6]

Flight deck

The DC-9 Series 10, as with all later versions of the DC-9 is equipped with a two crew analog flightdeck.[5][6]

Cabin

The aircraft is fitted with a passenger door in the port forward fuselage, and a service door/emergency exit is installed opposite. An airstair installed below the front passenger door was available as an option as was an airstair in the tailcone. This also doubled as an emergency exit. Available with either two or four overwing exits, the DC-9-10 can seat up to a maximum certified exit limit of 109 passengers. Typical all economy layout is 90 passengers, and 72 passengers in a more typical mixed-class layout with 12 first and 60 economy-class passengers.[5][6]

Undercarriage

All versions of the DC-9 are equipped with a tricycle undercarriage, featuring a twin nose unit and twin main units.[5][6]

Series 20

This was designed to satisfy a Scandinavian Airlines request for improved short field performance by using the more powerful engines and improved wings of the -30 combined with the shorter fuselage used in the -10. Ten Series 20 aircraft were produced, all of them Model -21.[7]

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.[8]

Dimensions

The Series 20 has an overall length of 104.4 feet (31.82 m), a fuselage length of 92.1 feet (28.07 m), a passenger cabin length of 60 feet (18.29 m), and a wingspan of 93.3 feet (28.44 m).[5][6]

Powerplant

The DC-9 Series 20 is powered by the 15,000 lb thrust JT8D-11 engine.[5][6]

Performance

The Series 20 was originally certificated at an MTOW of 94,500 lb but this has been increased to 98,000 lb, some 8% up on the higher weight Series 14s and 15s. The aircraft's MLW is 95,300 lb and MZFW is 84,000 lb. Typical range with maximum payload is 1,000 nm, increasing to 1,450 nm with maximum fuel. The Series 20, using the same wing as the Series 30 and indeed the Series 40 and 50, has a slightly lower basic fuel capacity than the Series 10 (3,679 US gallons).[5][6]

Programme Milestones

Series 30

The -30 was the definitive series, produced to counter Boeing's 737 twinjet, with 662 produced, accounting for about 60% of production. The -30 entered service with Eastern Airlines in February 1967 with a 14 ft 9 in (4.50 m) fuselage stretch, wingspan increased by just over 3 ft (0.9 m) and full-span leading edge slats, improving takeoff and landing performance. Gross take-off weight was typically 110,000 lb (50,000 kg). Engine options for Models -31, -32, -33 and -34 included the P&W JT8D-7 and JT8D-9 rated at 14,500 lbf (64 kN) of thrust, or JT8D-11 rated at 15,000 lbf (67 kN) of thrust.

Subvariants

The Series 30 was produced in four main sub-variants.[5][6]

Powerplant

The DC-9-30 was offered with a selection of variants of JT8D including the -1, -7, -9, -11, -15 and -17. The most common on the Series 31 is the JT8D-7 (14,000 lb thrust), although it was also available with the -9 and -17 engines. On the Series 32 the JT8D-9 (14,500 lb thrust) was standard, with the -11 also offered. The Series 33 was offered with the JT8D-9 or -11 (15,000 lb thrust) engines and the heavyweight -34 with the JT8D-9, -15 (15,000 lb thrust) or -17 (16,000 lb thrust) engines.[5][6]

Series 40

This further lengthened version entered service with SAS in March 1968. With a 6 ft 6 in (2 m) longer fuselage, accommodation was up to 125 passengers. The -40 was fitted with Pratt & Whitney engines of between 14,500 and 16,000 lbf (64 and 71 kN). A total of 71 were produced.

Series 50

The -50 was the largest DC-9 to fly. It features an 8 ft 2 in (2.49 m) fuselage stretch and seats up to 139 passengers. It started revenue service in August 1975 with Eastern Airlines and included a number of 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. McDonnell Douglas delivered 96, all as Model -51. Some visual cues to distinguish this version from other DC-9 variants include side strakes (fins) below the side cockpit windows and thrust reversers rotated about 22 degrees.

Military and government

A US Air Force C-9A Nightingale.

C-9: Several -30 series with side cargo door were purchased by the US armed forces. The C-9A Nightingale medevac configuration was for the U.S Air Force. The C-9B Skytrain II was for the U.S Navy and Marines, used for fleet logistics support moving both personnel and light cargo. The VC-9C is a VIP transport version for the US Air Force, used to transport Cabinet members and other high-ranking officials.

Versions of the DC-9 are also used by the Kuwait Air Force and Aeronautica Militare (Italian Air Force).

Operators

Two British Midland DC-9s at Teesside Airport in 1994.
Perris Valley Skydiving DC-9-21, January 2008

A total of 169 DC-9 aircraft (all variants) were in commercial service as of August 2010, including operators Delta Air Lines (46), ABX Air (28), Aserca Airlines (18), USA Jet Airlines (7), Aeropostal-LAV (4), Laser Airlines (4), Wimbi Dira Airways (4), and other operators with fewer aircraft.[9]

Delta Air Lines (formerly Northwest Airlines) operates a fleet of DC-9 aircraft, most of which are over 30 years old. With severe increases in fuel prices in the summer of 2008, Northwest Airlines finally began retiring its DC-9s, switching to Airbus A319s that are 27% more fuel efficient.[10][11]

Because of the usage of the aging JT8D engines, as of late 2000s DC-9s are considered gas guzzlers when compared to other more recent airliner designs. Studies aimed at improving DC-9 fuel efficiency, by means of retrofitted wingtip extensions of various types, have not succeeded in demonstrating significant benefits.

With the existing DC-9 fleet shrinking, modifications do not appear to be likely to occur, especially since the wing design makes retrofitting difficult.[4] Thus, DC-9s are likely to be further replaced in service by new Boeing 737, Airbus A320, Embraer E-Jets aircraft, or the new, emerging Bombardier CSeries airliner.[12] However, it is probable that a modest number of DC-9s will continue to productively fly for many years to come. As the Northwest/Delta merger progresses, Delta has pulled several stored DC-9s back into service.

One ex SAS DC-9-21 is operated as a skydiving jump platform at Perris Valley Airport in Perris, California. 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 2008.[13]

Accidents and incidents

As of March 2009, the DC-9 has been involved in 117 incidents, including 101 hull-loss accidents,[14] with 2,135 fatalities.[15]

Notable accidents

An Itavia DC-9 (I-TIGI) which was lost in an accident at Ustica in 1980.
Itavia DC-9 (I-TIGI) was destroyed in an accident at Ustica. Shown in the "Museo della Memoria" opened in Bologna in 2007.

On November 9, 1999, TAESA Flight 725 crashed a few minutes after leaving the Uruapan Airport en-route to Mexico City. 18 people were killed in the accident.[30]

Specifications

DC-9-10 DC-9-20 DC-9-30 DC-9-40 DC-9-50
Passengers
(1 class)		 90 115 125 135
Max takeoff
weight		 90,700 lb
(41,100 kg)		 98,000 lb
(44,500 kg)		 110,000 lb
(49,900 kg)		 114,000 lb
(51,700 kg)		 121,000 lb
(54,900 kg)
Max range 1,265 nmi
(2,340 km)		 1,850 nmi
(3,430 km)		 1,635 nmi
(3,030 km)		 1,685 nmi
(3,120 km)		 1,635 nmi
(3,030 km)
Cruising speed 561 mph
(903 km/h)		 557 mph
(896 km/h)		 570 mph
(917 km/h)		 558 mph
(898 km/h)
Length 104 ft 5 in (31.82 m) 119 ft 4 in (36.37 m) 125 ft 7 in (38.28 m) 133 ft 7 in (40.72 m)
Wingspan 89 ft 5 in (27.25 m) 93 ft 5 in (28.47 m)
Tail height 27 ft 5 in (8.38 m)
Powerplants (2x) Pratt & Whitney JT8D-5 or -7 Pratt & Whitney JT8D-11 Pratt & Whitney JT8D-7, -9, -11 or -15 Pratt & Whitney JT8D-15 or -17
Engine thrust 12,500 to 14,000 lbf (62.3 kN) 15,000 lbf (66.7 kN) 14,000 to 15,500 lbf (68.9 kN) 15,500 to 16,000 lbf (71.2 kN)
Allegheny Airlines DC-9-30 circa 1970

Sources: McDonnell Douglas DC-9 data.[34]

See also

Related development

Comparable aircraft

Related lists

References

  1. ↑ 1.0 1.1 1.2 1.3 Endres, Gunter. McDonnell Douglas DC-9/MD-80 & MD-90. London: Ian Allan, 1991. ISBN 0-7110-1958-4.
  2. ↑ 2.0 2.1 2.2 2.3 Norris, Guy and Mark Wagner. "DC-9: Twinjet Workhorse". Douglas Jetliners. MBI Publishing, 1999. ISBN 0-7603-0676-1.
  3. ↑ "DC-1 Commercial Transport". Boeing. http://www.boeing.com/history/mdc/dc-1.htm. Retrieved 27 March 2010. 
  4. ↑ 4.0 4.1 Assessment of Wingtip Modifications to Increase the Fuel Efficiency of Air Force Aircraft. The National Academies Press. 2007. pp. 40. ISBN 0-309-10497-1. http://books.nap.edu/openbook.php?record_id=11839&page=40. 
  5. ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 5.11 Airclaims Jet Programs 1995
  6. ↑ 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 Jane's Civil and Military Aircraft Upgrades 1995
  7. ↑ The Boeing Company
  8. ↑ http://www.flightglobal.com/pdfarchive/view/1969/1969%20-%200179.html
  9. ↑ DC-9 family plane list. planelist.net, April 5, 2009.
  10. ↑ "To Save Fuel, Airlines Find No Speck Too Small". New York Times, June 11, 2008.
  11. ↑ Soaring Fuel Prices Pinch Airlines Harder, Wall Street Journal, June 18, 2008, p. B1.
  12. ↑ Bombardier Launches CSeries Jet, New York Times, July 13, 2008.
  13. ↑ Perris Valley Skydiving DC-9 Video
  14. ↑ McDonnell Douglas DC-9-10/15 summary, DC-9-20 summary, DC-9-30 summary, DC-9-40 summary, DC-9-50 summary. Aviation-Safety.net.
  15. ↑ McDonnell Douglas DC-9-10/15 Statistics, DC-9-20 Statistics, DC-9-30 Statistics, DC-9-40 Statistics, DC-9-50 Statistics. Aviation-Safety.net, 3 December 2007.
  16. ↑ National Transportation Safety Board (1967-12-11). "Aircraft Accident Report. West Coast Airlines, Inc DC-9 N9101. Near Wemme, Oregon". http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR67-AF.pdf. Retrieved 2009-03-22. 
  17. ↑ National Transportation Safety Board (1968-06-19). "Aircraft Accident Report. Trans World Airlines, Inc., Douglas DC-9, Tann Company Beechcraft Baron B-55 In-flight Collision near Urbana, Ohio, March 9, 1967". AirDisaster.Com. http://www.airdisaster.com/reports/ntsb/AAR68-AI.pdf. Retrieved 2008-11-23. 
  18. ↑ "Accident description". Aviation Safety Network. http://aviation-safety.net/database/record.php?id=19690627-0. Retrieved 7 October 2009. 
  19. ↑ NTSB Report (PDF)
  20. ↑ McGlaun, Dan. "Allegheny 853 Crash Site Pictures". www.mcglaun.com. http://www.mcglaun.com/1969pics.htm. Retrieved 2008-01-27. 
  21. ↑ D. Gero (2005-05-21). "ASN Aircraft accident McDonnell Douglas DC-9-32 HI-177 Santo Domingo". Aviation Safety Network. Flight Safety Foundation. http://aviation-safety.net/database/record.php?id=19700215-0. Retrieved 2008-11-23. 
  22. ↑ "Former Champ Teo Cruz Dies in Plane Crash". Modesto Bee. Associated Press (Modesto, California): p. A-6. 1970-02-16. http://www.newspaperarchive.com/freepdfviewer.aspx?img=43102954. Retrieved 2008-11-23. 
  23. ↑ National Transportation Safety Board (1971-03-31). "Aircraft Accident Report: Overseas National Airways, Inc., operating as Antilliaanse Luchtvaart Maatschappij Flight 980, near St. Croix, Virgin Islands, May 2, 1970. DC-9 N935F.". AirDisaster.Com. http://www.airdisaster.com/reports/ntsb/AAR71-08.pdf. Retrieved 2008-11-23. 
  24. ↑ National Transportation Safety Board (1978-01-26). "Aircraft Accident Report: Southern Airways, Inc. DC-9-31, N1335U. New Hope, Georgia. April 4, 1977.". AirDisaster.Com. http://www.airdisaster.com/reports/ntsb/AAR78-03.pdf. Retrieved 2008-11-23. 
  25. ↑ Vanderbilt, Tom (2010-03-12). "When Planes Land on Highways: The ins and outs of a surprisingly frequent phenomenon". Slate. http://www.slate.com/id/2247545/. 
  26. ↑ Priest, Lisa; Rick Cash (2005-03-08). "Takeoffs and landings always pose risk of calamity, as history shows" (Fee required.). Globe & Mail (Toronto, Ontario, Canada). http://www.theglobeandmail.com/servlet/ArticleNews/TPStory/LAC/20050803/PLANELASTIME03/TPNational/Canada. Retrieved 2008-11-23. "The last time an aircraft skidded off the runway in Toronto, seriously injuring passengers, was more than a quarter-century ago. On June 26, 1978, an Air Canada DC-9 skidded off a taxi strip at Toronto International Airport (what is today Pearson International Airport) during an aborted takeoff, then belly-flopped into a swampy ravine, killing two passengers and injuring more than a hundred others." 
  27. ↑ "ASN Aircraft Accident description of the 14 SEP 1979 accident of a McDonnell Douglas DC-9-32 I-ATJC at Sarroch". Aviation Safety Network. Flight Safety Foundation. February 21, 2006. http://aviation-safety.net/database/record.php?id=19790914-1. Retrieved 2008-11-23. 
  28. ↑ "ASN Aircraft accident Douglas DC-9-14 N3313L Detroit-Metropolitan Wayne County Airport, Michigan (DTW)". Aviation Safety Network. Flight Safety Foundation. 2008-11-23. http://aviation-safety.net/database/record.php?id=19901203-1. Retrieved 2008-11-23. 
  29. ↑ National Transportation Safety Board (1991-06-25). "Aircraft Accident Report: Northwest Airlines Inc. Flights 1482 & 299, Runway Incursion and Collision, Detroit Metropolitan/Wayne County Airport, Romulus, Michigan, December 3, 1990". AirDisaster.Com. http://www.airdisaster.com/reports/ntsb/AAR91-05.pdf. Retrieved 2008-11-23. 
  30. ↑ "ASN Aircraft accident McDonnell Douglas DC-9-31F XA-TKN Uruapan." Aviation Safety Network. Retrieved on July 4, 2010.
  31. ↑ "Plane crashes into African marketplace", CNN, April 15, 2008.
  32. ↑ "Toll from Congo plane crash rises to 44". Associated Press, 2008-04-17
  33. ↑ USA Jet Flight 199. aviation-safety.net
  34. ↑ MDC J2904F DC-9 Airplane Characteristics for Airport Planning. McDonnell Douglas, June 1984.

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