Douglas DC-9

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 aircraft family ceased after 41 years and nearly 2,500 units built.

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.

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. Douglas officially gave approval to produce the DC-9 on April 8, 1963. 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. 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. 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.)

File:NWAdc9YQR.jpg

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. The initial Series 10 would be followed by subsequent growth variants. The final DC-9 series was the -50, which first flew in 1974. The DC-9 was a commercial success with 976 built when the production ended in 1982.

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 3,000 produced, and the first place Boeing 737 with over 6,000 produced.

File:Douglas Curtis - 9 Cebu-Pacific PH.jpg

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.

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

File:DC-9 Cockpit.jpg

DC-9-40 flight deck.

File:Navy-dc9-N932ML-071129-01adj-16.jpg

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 -10 series was earliest and smallest DC-9 series. The -10 was Template:Convert long and had a maximum weight of Template:Convert. Power was a pair of Template:Convert Pratt & Whitney JT8D-5 or Template:Convert 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.

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.

Series 30

The -30 was the definitive series with 662 produced, accounting for about 60% of production. The -30 entered service with Eastern Airlines in February 1967 with a Template:Convert fuselage stretch, wingspan increased by just over Template:Convert and full-span leading edge slats, improving takeoff and landing performance. Gross take-off weight was typically Template:Convert. Engine options for Models -31, -32, -33 and -34 included the P&W JT8D-7 and JT8D-9 rated at Template:Convert of thrust, or JT8D-11 rated at Template:Convert of thrust.

Series 40

This further lengthened version entered service with SAS in March 1968. With a Template:Convert longer fuselage, accommodation was up to 125 passengers. The -40 was fitted with Pratt & Whitney engines of between Template:Convert. A total of 71 were produced.

Series 50

The -50 was the largest DC-9 to fly. It features an Template:Convert 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 Template:Convert 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.

Template:AnchorC-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

File:Perris DC-9-21 at Perris January 2008.jpg

Perris Valley Skydiving DC-9-21, January 2008

A total of 216 DC-9 aircraft (all variants) were in service as of July 2009, including commercial operators Northwest Airlines (67), ABX Air (41), Aserca Airlines (18), USA Jet Airlines (8), Laser YV (4), Aeropostal-LAV (4), and other operators with fewer aircraft.

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.

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. 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. 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.

Accidents and incidents

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

Notable accidents

• On October 1 1966, West Coast Airlines Flight 956 crashed with eighteen fatalities and no survivors. This accident marks the first loss of a DC-9.

• On March 9 1967, TWA Flight 553 fell to earth in a field in Concord Township, near Urbana, Ohio, following a mid-air collision with a Beechcraft Baron, an accident which triggered substantial changes in air traffic control procedures.

• On September 9 1969, Allegheny Airlines Flight 853, a McDonnell Douglas DC-9-30, collided in mid-air with a Piper PA-28 Cherokee near Fairland, Indiana. The DC-9 carried 78 passengers and 4 crew members, the Piper one pilot. The occupants of both aircraft were killed in the accident and the aircraft were destroyed.Template:Citation needed

• On February 15 1970, a Dominicana de Aviacion DC-9 crashed after taking off from Santo Domingo. The "Dominicana DC-9 air disaster", possibly caused by contaminated fuel, killed all 102 passengers and crew, including champion boxer Teo Cruz.

• On May 2 1970, an Overseas National Airways DC-9, wet-leased to ALM Dutch Antilles Airlines and operating as ALM Flight 980, ditched in the Caribbean Sea on a flight from New York's John F. Kennedy International Airport to Princess Juliana International Airport on Sint Maarten. After three landing attempts in poor weather at Sint Maarten, the pilots began to divert to their alternate of Saint Croix, U.S. Virgin Islands but ran out of fuel 30 mi ( km) short of the island. After about 10 minutes, the aircraft sank in 5,000 ft ( m) of water and was never recovered. 40 people survived the ditching, 23 perished.

• On November 14 1970, a Southern Airways Flight 932 DC-9 crashed into a hill near Tri-State Airport in Huntington, West Virginia. All 75 on board were killed (including 37 members of the Marshall University Thundering Herd football team, eight members of the coaching staff, 25 boosters, and others).

• On January 26 1972, Jugoslovenski Aero Transport Flight 367 DC-9-32 (registration: YU-AHT) was destroyed in flight by a bomb placed onboard the aircraft. The sole survivor was a flight attendant, Vesna Vulović, who holds the record for the world's longest fall without a parachute when she fell some Template:Convert inside the tail section of the airplane and survived.

• On July 31 1973, Delta Air Lines Flight 723, operated on a DC-9-31 (registration: N975NE), crashed into a seawall at Logan International Airport in Boston, Massachusetts, killing all 83 passengers and 6 crew members on board. One of the passengers initially survived the accident but died in hospital.

• On September 11 1974, Eastern Air Lines Flight 212 DC-9-30 crashed just short of the runway at Charlotte, North Carolina, killing 71 out of the 82 occupants.

• On September 10 1976, an Inex-Adria Aviopromet DC-9 collided with a British Airways Trident over the Croatian town of Vrbovec, killing all 176 people aboard both aircraft.

• On April 4 1977, Southern Airways Flight 242, a DC-9-31 crash landed onto then a highway in New Hope, Georgia, US. The crash and fire resulted in the death of both flight crew and 61 passengers. Nine people on the ground also died. Both flight attendants and 20 passengers survived.

• On June 26 1978, Air Canada Flight 189 DC-9 overran the runway in Toronto after a blown tire aborted the takeoff. 2 of 107 passengers and crew were killed.

• On September 14 1979, Aero Trasporti Italiani Flight 12, a DC-9-32 crashed in the mountains near Cagliari, Italy while approaching Cagliari-Elmas Airport. All 27 passengers and 4 crew members died in the crash and ensuing fire.

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An Itavia DC-9 (I-TIGI) which was lost in an accident at Ustica in 1980.

File:Museo ustica.JPG

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

• On June 27 1980, a DC-9-15 carrying Aerolinee Itavia Flight 870 suffered an in-flight explosion and crashed into the sea near the Italian island of Ustica. All 81 people on board were killed. The causes of this accident are still unclear.

• On December 1 1981, Inex-Adria Aviopromet Flight 1308 crashed in the mountains while approaching Campo dell'Oro Airport in Ajaccio, Corsica, killing 173 passengers and 7 crew members.

• On June 2 1983, Air Canada Flight 797 DC-9 experienced an electrical fire in the aft lavatory during flight, resulting in an emergency landing at Cincinnati/Northern Kentucky International Airport. During evacuation, the sudden influx of oxygen caused a flash fire throughout the cabin, resulting in the deaths of 23 of the 41 passengers, including Canadian folk singer Stan Rogers. All five crew members survived.

• On August 31 1986, Aeromexico Flight 498 collided in mid-air with a Piper Cherokee over the city of Cerritos, California, then crashed into the city, killing all 67 aboard the aircraft, 15 people on the ground, and all 3 in the small plane.

• On December 3 1990, Northwest Airlines Flight 1482, a DC-9-14, went on the wrong taxiway in dense fog at Detroit-Metropolitan Wayne County Airport, MI (DTW). It entered the active runway instead of taxiway instructed by air traffic controllers. It collided with a departing Northwest Boeing 727. Nine people were killed.

• On July 2 1994, USAir Flight 1016 crashed in Charlotte, North Carolina while performing a go-around because of heavy storms and wind shear at the approach of runway 18R. There were 37 fatalities and 15 injured among the passengers and crew. Although the airplane came to rest in a residential area with the tail section striking a house, there were no fatalities or injuries on the ground.

• On May 11 1996 ValuJet Flight 592 crashed in the Florida Everglades due to a fire caused by the activation of chemical oxygen generators illegally stored in the hold. The fire damaged the plane's electrical system and eventually overcame the crew, resulting in the deaths of 110 people.

• In October 1997, Austral Flight 2553, DC-9-32, registration LV-WEG, en route from Posadas to Buenos Aires, crashed near Fray Bentos, Uruguay, killing 74 people (69 passengers and 5 crew).

• On February 2 1998, Cebu Pacific Flight 387 crashed on the slopes of Mount Sumagaya in Misamis Oriental, Philippines, killing all 104 people on board. Aviation investigators deemed the incident to be caused by pilot error when the plane made a non-regular stopover to Tacloban.

• On October 6 2000, Aeroméxico Flight 250 en route from Mexico City to Reynosa, Mexico, could not stop before the runway ended and it crashed into houses and fell into a small canal, killing four people from the houses. The 83 passengers and 5 crew members were not reported dead. The cause of the crash was due to poor visibility during a storm.Template:Citation needed

• On April 15 2008, a Hewa Bora Airways DC-9 crashed into a residential neighborhood, in the Goma, Democratic Republic of the Congo, resulting in the deaths of at least 44 people.

• On July 6, 2008, A DC-9, operating as USA Jet Flight 199, crashed and burned near the airport in Saltillo, Mexico, killing the captain and seriously injuring the first officer. The cause of the crash is still under investigation.Template:Citation needed

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)

File:Douglas DC-9-30 Allegheny N993VJ.png

Allegheny Airlines DC-9-30 circa 1970

• Cabin cross section:
  • External width: 10 ft 11.6 in (3.34 m)
  • Internal width: 10 ft 3.7 in (3.14 m)
  • External height: 11 ft 8 in (3.6 m)
  • Internal height: 6 ft 9 in (2.06 m)

Sources: McDonnell Douglas DC-9 data.

See also

Related development

• C-9 Skytrain/Nightingale
• McDonnell Douglas MD-80
• McDonnell Douglas MD-90
• Boeing 717
• ACAC ARJ21

Comparable aircraft

• BAC-111
• Sud Aviation Caravelle
• Tupolev Tu-134
• Boeing 727
• Fokker F28

Related lists

• List of civil aircraft

See also

• Airstair
• N900SA

References

• Becher, Thomas. Douglas Twinjets, DC-9, MD-80, MD-90 and Boeing 717. The Crowood Press, 2002. ISBN 1-86126-446-1.

External links

Wikimedia Commons has media related to:

McDonnell Douglas DC-9

• DC-9 page on Boeing.com
• DC-9 history page on Boeing.com
• DC-9-10/20/30 on Airliners.net and DC-9-40/50 on Airliners.net
• DC-9 History on AviationHistoryOnline.com
• Airliners Historical Overviews/Aircraft Specifications/Crash Statistics

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Douglas DC-9".