Douglas DC-7

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File:BOAC DC-7C Taking-off from Manchester.jpg

BOAC DC-7C G-AOIC taking off from Manchester UK in April 1958 for a non-stop flight to New York (Idlewild) (later JFK)

Swissair DC-7C in 1961

File:Douglas DC-7F G-AOIJ BOAC Frt RWY 10.61 edited-2.jpg

DC-7CF freighter of BOAC in 1961 converted with forward and rear freight doors

The Douglas DC-7 is a retired American transport aircraft built by the Douglas Aircraft Company from 1953 to 1958. A derivative of the DC-6, it was the last major piston engine-powered transport made by Douglas, being developed shortly after the earliest jet airliner—the de Havilland Comet—entered service and only a few years before the jet-powered Douglas DC-8 first flew in 1958. Larger numbers of both DC-7B and DC-7C variants were also built.

Unlike other far more successful propeller-driven Douglas aircraft, such as the DC-3 and DC-6, no examples of the DC-7 remain in service as of 2020.<ref name=":1">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Design and developmentEdit

In 1945, Pan American World Airways requested a DC-7, a civil version of the Douglas C-74 Globemaster military transport. Pan Am soon canceled their order. That proposed DC-7 was unrelated to the later DC-6-derived airliner.<ref name="janes46">Template:Cite book</ref>

American Airlines revived the designation when they requested an aircraft that could fly across the United States coast-to-coast non-stop in about eight hours. (Civil Air Regulations then limited domestic flight crews to 8 hours' flight time in any 24-hour period.<ref>Aviation Week, February 1, 1954, p. 16.</ref><ref>Aviation Week, June 21, 1954 p. 16.</ref>) Douglas was reluctant to build the aircraft until American Airlines president C. R. Smith ordered 25 at a total price of $40 million, thus covering Douglas' development costs.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

The DC-7 wing was based on that of the DC-4 and DC-6, with the same span; the fuselage was Template:Convert longer than the DC-6B. Four eighteen-cylinder Wright R-3350 Duplex-Cyclone Turbo-Compound engines provided power.<ref>"Douglas Airlines". Sport Aviation, April 2012, p. 19.</ref> The prototype flew in May 1953 and American received their first DC-7 in November, inaugurating the first non-stop east-coast-to-west-coast service in the country (unrealistically scheduled just under the eight-hour limit for one crew) and forcing rival TWA to offer a similar service with its Super Constellations. Both aircraft frequently experienced inflight engine failures, causing many flights to be diverted. Some blamed this on the need for high-power settings to meet the national schedules, causing overheating and failure of the engines' power recovery turbines.<ref>Aviation Week, April 21, 1958, p. 38:</ref>

DC-7BEdit

The DC-7 was followed by the DC-7B with slightly more power and optional fuel tanks over the wing in the rear of the engine nacelles (selected by Pan Am and South African Airways), each carrying Template:Convert. South African Airways used this variant to fly Johannesburg to London with one stop. Pan Am's DC-7Bs started flying transatlantic in summer 1955, scheduled 1 hr 45 min faster than the Super Stratocruiser from New York to London or Paris.

DC-7CEdit

Early DC-7s were purchased only by U.S. carriers. European carriers could not take advantage of the small range-increase of the early DC-7, so Douglas released an extended-range variant, the DC-7C (Seven Seas) in 1956. Two Template:Convert wingroot inserts added fuel capacity, reduced interference drag and made the cabin quieter by moving the engines farther outboard; the optional nacelle fuel tanks previously seen on Pan American's and South African's DC-7Bs were made standard. The fuselage, which had been extended over the DC-6Bs with a Template:Convert plug behind the wing for the DC-7 and DC-7B, was lengthened again with a 40-inch plug ahead of the wing to give the DC-7C a total length of Template:Convert.

Operational historyEdit

Since the late 1940s Pan Am and other airlines had scheduled a few non-stop flights from New York to Europe, but westward non-stops against the prevailing wind were rarely possible with an economic payload. The Lockheed Super Constellation and DC-7B that appeared in 1955 could occasionally make the westward trip, but in summer 1956 Pan Am's DC-7C finally started doing it fairly reliably. BOAC was forced to respond by purchasing DC-7Cs rather than wait on the delivery of the Bristol Britannia. The DC-7C found its way into several other overseas airlines' fleets, including SAS, which used them on cross-polar flights to North America and Asia. The DC-7C sold better than its rival, the Lockheed L-1649A Starliner, which entered service a year later,<ref>Breffort, Dominique. Lockheed Constellation: From Excalibur to Starliner, Civilian and Military Variants. Paris: Histoire and Collecions, 2006. Template:ISBN</ref> but sales were cut short by the arrival of Boeing 707 and Douglas DC-8 jets in 1958–60.

Starting in 1959 Douglas began converting DC-7s and DC-7Cs into DC-7F freighters to extend their useful lives. The airframes were fitted with large forward and rear freight doors and some cabin windows were removed.

The predecessor DC-6, especially the DC-6B, established a reputation for straightforward engineering and reliability. Pratt & Whitney, manufacturer of the DC-6s Double Wasp engines, did not offer an effective larger engine apart from the Wasp Major, which had a reputation for poor reliability.Template:Citation needed Douglas turned to Wright Aeronautical for a more powerful engine. The Duplex-Cyclone had reliability issues of its own, and this affected the DC-7's service record. Carriers who had both DC-6s and DC-7s in their fleets usually replaced the newer DC-7s first once jets started to arrive. Some airlines retired their DC-7s after little more than five years of service, whereas most DC-6s lasted longer and sold more readily on the secondhand market.

Basic price of a new DC-7 was around $823,308 (£570,000).<ref name=autogenerated1>"Max take-off, Hamilton Standard, price today." Flight Archive, 1960.</ref>

Price of a DC-7B was around $982,226 (£680,000) in 1955, rising to $1,184,490 (£820,000) in 1957.<ref name=autogenerated1 />

Similarly, the price of a DC-7C was $1,155,560 (£800,000) in 1956, increasing to $1,343,385 (£930,000) by 1958.<ref name=autogenerated2>"Douglas." Flight Archive, 1960.</ref>

Cost of the DC-7F "Speedfreighter" conversion was around $166,112 (£115,000) per aircraft.<ref name=autogenerated2 />

VariantsEdit

DC-7: Production variant, 105 built.
DC-7B: First long-range variant with higher gross weight and fuel capacity, with most of the added fuel in saddle tanks in enlarged engine nacelles. (Only Pan Am and South African DC-7Bs had the saddle tanks.) 112 built.
DC-7C Seven Seas: Longer-range variant with non-stop transatlantic capability, improved Template:Cvt R-3350 engines and increased fuel capacity mainly in longer wings, 121 built.
DC-7D: Unbuilt variant with Rolls-Royce Tyne turboprops.
DC-7F: Freight conversion of all three variants with two large freight doors.

OperatorsEdit

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File:Butler-dc7-N6353C-071029-fox-tanker66-04-16.jpg

Butler Aircraft Services' DC-7, Tanker 66

AirlinesEdit

DC-7s were used by Alitalia, American Airlines, BOAC, Braniff Airways, Caledonian Airways, Delta Air Lines, Eastern Air Lines, Flying Tigers, Japan Airlines, KLM, Mexicana de Aviacion, National Airlines, Northwest Orient, Panair do Brasil, Pan American World Airways, Riddle Airlines, Sabena, SAS, South African Airways, Swissair, Turkish Airlines, Transports Aériens Intercontinentaux, and United Airlines.

Seventeen DC-7s remained on the U.S. registry in 2010,<ref>"FAA registration database." Template:Webarchive FAA. Retrieved: November 26, 2010.</ref> they were used mainly for cargo and as aerial firefighting airtankers. Due to its engine problems, the DC-7 has not had the same longevity as the DC-6, which is still used by a number of commercial operators.Template:Citation needed

Military operatorsEdit

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Template:Flag Flown by civilian sanctions buster Jack Malloch

Orders and productionEdit

Airline	DC-7	DC-7B	DC-7C	Notes
Alitalia	—	—	Template:06
American Airlines	34	24	—	Launch customer for the DC-7 with an original order for 25
Braniff Airways	—	—	Template:07
British Overseas Airways Corporation	—	—	10
Continental Air Lines	—	Template:05	—
Delta Air Lines	10	10	—
Eastern Air Lines	—	49	—
Iran Air	—	—	Template:01
Japan Air Lines	—	—	Template:04
KLM	—	—	15
Mexicana	—	—	Template:04
National Airlines	Template:04	Template:04	—
Northwest Orient Airlines	—	—	14
Panair do Brasil	—	—	Template:06
Panagra	—	Template:06	—
Pan American World Airways	—	Template:06	27
Persian Air Services	—	—	Template:02
Sabena	—	—	10	3 were leased
Scandinavian Airlines System	—	—	14
South African Airways	—	Template:04	—
Swissair	—	—	Template:05
Transports Aériens Intercontinentaux	—	—	Template:04
United Airlines	57	—	—	2 were lost in mid-air collisions
Douglas Aircraft	—	Template:02	—	Written off before delivery
	—	Template:01	—	DC-7B prototype delivered to Delta Air Lines
	—	—	Template:01	DC-7C prototype delivered to Panair do Brasil
Total	105	112	121	Total built: 338

Accidents and incidentsEdit

The Douglas DC-7 suffered 82 incidents and accidents with a total of 714 fatalities.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

June 30, 1956: United Airlines Flight 718, a DC-7, (N6324C) collided over the Grand Canyon with TWA Flight 2, an L-1049 Super Constellation (N6902C), resulting in the deaths of 128 people on both aircraft.

January 31, 1957: A DC-7 (N8210H) still owned by Douglas crashed into a school yard in the Pacoima area of Los Angeles, California, following a midair collision with Northrop F-89J Scorpion 52-1870, resulting in the deaths of the four crewmembers aboard the DC-7, the pilot of the Scorpion jet, and three students on the ground.<ref>Template:Cite news</ref><ref>Template:ASN accident</ref>

March 5, 1957: An American Air Lines DC-7B (N316AA) on a flight from Idlewild (JFK) airport to Love Field (Dallas) suffered failure of the #1 engine. The propeller and nose section detached and struck the fuselage, leading to decompression. The pilot made a successful emergency landing at Memphis; there were no fatalities or injuries. The plane was repaired and returned to service.<ref>Template:ASN accident</ref>

June 28, 1957: An Eastern Air Lines DC-7B (N808D) collided with a parked Eastern Air Lines Lockheed L-1049 (N6212C) at Miami International Airport after returning from a training flight. Fuel leaked and both aircraft burned out.<ref>Template:ASN accident</ref>

February 1, 1958: Pan Am Flight 70, a DC-7C (N733PA, Clipper Blue Jacket), landed wheels-up at Schiphol Airport as a result of pilot error; all 16 on board survived. The aircraft was repaired and returned to service as a freighter.<ref>Template:ASN accident</ref> See also July 26, 1970 below.

March 10, 1958: A DC-7B (N846D) still owned by Douglas crashed at Long Beach, California during a test flight before delivery to Eastern Air Lines.<ref>Template:ASN accident</ref>

March 25, 1958: Braniff Flight 971, a DC-7C (N5904), crashed shortly after takeoff from Miami while attempting to return after an engine caught fire. Nine passengers out of 24 people aboard died in the accident.<ref>"Douglas DC-7C N5904". Aviation Safety Network. Retrieved: September 6, 2013.</ref>

April 21, 1958: United Airlines Flight 736, a DC-7 (N6328C) en route from Los Angeles to Denver, collided with a Nellis Air Force Base, North American F-100 Super Sabre "F-100F" (two-seater) (56-3755) near Las Vegas. Both aircraft crashed out of control resulting in the deaths of 49 people.

May 18, 1958: A Sabena DC-7C (OO-SFA) crashed near Casablanca–Anfa Airport during the attempted landing. All nine crewmembers and 52 of the 56 passengers died.<ref>"Douglas DC-7C OO-SFA." Aviation Safety Network. Retrieved: September 6, 2013.</ref>

September 24, 1959: TAI Flight 307, a DC-7C, crashed at Bordeaux airport with the loss of 54 lives. After takeoff, the aircraft failed to gain altitude and collided with trees Template:Convert from the start of the takeoff.

November 16, 1959: National Airlines Flight 967, a DC-7B on a flight from Tampa, Florida, to New Orleans, crashed into the Gulf of Mexico. All 42 occupants perished. Although sabotage was suspected, no definite cause of the crash was determined due to a lack of evidence. The aircraft was owned by Delta Air Lines.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

February 26, 1960: Alitalia Flight 618, a DC-7C (I-DUVO), crashed at Shannon Airport, Ireland, shortly after takeoff following a loss of altitude while making a left turn with 34 fatalities out of 52 passengers and crew. No cause was established for this accident.<ref>Template:ASN accident</ref>

June 27, 1960: A Cubana de Aviación DC-7 took off from José Martí International Airport, Cuba, to Idlewood Intl’l (now JFK International Airport). Near cruising altitude, engine #3 and #4 failed and caught fire. They safely landed at Key West International Airport with no fatalities.

July 14, 1960: Northwest Orient Airlines Flight 1-11, a DC-7C (N292), ditched off Polillo Island, Philippines due to failure of the number two engine and fire; one person (out of 58 on board) died when the number two propeller separated and penetrated the fuselage.<ref>Template:ASN accident</ref>

February 18, 1961: A Pan AM DC-7CF (N745PA) struck a mound of earth short of the runway in Stuttgart while attempting an ILS approach, shearing off the undercarriage and #1 engine. The pilots retained control and were able to climb away, then make a belly landing at Nurnberg airport. The aircraft was written off.<ref>Template:ASN accident</ref>

November 1, 1961: A Panair do Brasil DC-7C (PP-PDO) flying from Sal to Recife crashed into a hill about Template:Convert short of the runway at Recife. Forty-five passengers and crew out of the 88 persons aboard lost their lives. The accident was attributed to pilot error.<ref>"Accident description PP-PDO." Aviation Safety Network. Retrieved: May 20, 2011.</ref><ref>Germano da Silva 2008, pp. 197–203.</ref>

March 4, 1962: Caledonian Airways Flight 153 crashed into a swamp shortly after takeoff from Douala International Airport; all 111 people on board died. It is the worst single-aircraft accident of a DC-7.<ref>Template:ASN accident</ref>

October 22, 1962: Northwest Airlines Flight 292, a DC-7C (N285) with 7 crew and 95 passengers,<ref>Template:Cite book</ref> made a successful water landing in Sitka Sound just before 1 p.m. local time after struggling with propeller problems for 45 minutes<ref>Template:Cite news</ref> while operating as a military charter flight between McChord Air Force Base and Elmendorf Air Force Base. The plane stayed afloat for 24 minutes after coming to rest in the water, giving the occupants ample time to evacuate into life rafts with only 6 minor injuries reported. All passengers and crew were quickly rescued by U.S. Coast Guard ships.<ref>Template:Cite news</ref> The cause was an overspeeding propeller when the blower section on engine number two failed.

November 30, 1962: Eastern Air Lines Flight 512, a DC-7B on a flight from Charlotte, North Carolina, to New York-Idlewild, crashed after a missed approach due to fog. This accident, which cost 25 lives (out of 51 on board), was attributed to improper crew procedures.

June 3, 1963: Northwest Airlines Flight 293, a Military Air Transport Service flight from McChord Air Force Base in Washington state to Elmendorf Air Force Base in Alaska crashed into the Pacific Ocean near Annette Island, Alaska, with the loss of all 101 people aboard. Due to the lack of evidence, no cause was established for this accident.

February 8, 1965: Eastern Air Lines Flight 663 crashed a few minutes after takeoff from John F. Kennedy Airport in New York after taking evasive action to avoid a possible collision with another airliner (Pan Am Flight 212, a Boeing 707). All 84 passengers and crew died.

December 7, 1968: A North American Aircraft Trading DC-7C (VR-BCY) crashed during approach to Uli Airstrip following triple engine failure during a relief flight, killing all four crew.<ref>Template:ASN accident</ref>

June 5, 1969: A Swedish Red Cross DC-7B (SE-ERP) was shot down by a Nigerian Air Force MiG-17 and crashed at Eket, Nigeria, killing all four crew. The aircraft was operating a supply flight from Fernando Po (now Bioko) to Biafra.<ref>Template:ASN accident</ref>

July 26, 1970: An ARCO ferry flight of a DC-7CF (VR-BCT), from Kinshasa suffered an explosive failure of the #3 engine. The pilots succeeded in making a belly landing on 2 engines (engine #4 having been inoperable for the entire flight), however the plane was damaged beyond repair. This aircraft had previously crashed in 1958.<ref>Template:ASN accident</ref>

October 2, 1970: A Spantax DC-7C (EC-ATQ) was written off at Barajas Airport.<ref>Template:ASN accident</ref>

December 31, 1972: Professional Baseball player Roberto Clemente and 4 others in a chartered DC-7 died when the plane crashed shortly after takeoff from San Juan, Puerto Rico. Only parts of the fuselage and the body of pilot Jerry Hill were recovered. The cause was traced to maintenance and pilot errors.<ref>"Roberto Clemente While Flying A Relief Mission To Earthquake Torn Nicaragua Dies In Plane Crash." avstop.com. Retrieved: November 26, 2010.</ref>

June 21, 1973: A Skyways International DC-7C (N296) crashed in the Everglades six minutes after takeoff from Miami International Airport, apparently caused by an onboard fire and/or severe turbulence. Three crew members, the sole occupants, died. The aircraft was on lease to Warnaco Incorporated.<ref>Template:ASN accident</ref>

March 3, 1974: A Douglas DC-7C/F (EI-AWG) operating an Aer Turas Teo charter flight from Dublin landed at Luton Airport on runway 08 just after midnight but failed to achieve reverse thrust. Normal braking application also was ineffective and the emergency pneumatic brakes were applied. All main wheel tires burst. The aircraft overran the runway and continued over the steep bank at the eastern perimeter finally coming to rest in soft ground 90 metres beyond. The situation had also been made worse by an inadvertent application of forward thrust by the crew in trying to achieve reverse thrust. Three of the six passengers and two of the four crew were injured. The badly damaged aircraft was written off.<ref>"Accident description: Douglas DC-7CF EI-AWG". Aviation Safety Network, 2013. Retrieved: October 10, 2013.</ref>

October 4, 1976: An Emirates Air Transport DC-7CF (TZ-ARC) struck Mount Kenya due to a premature descent, killing the four crew.<ref>Template:ASN accident</ref>

September 12, 1977: A Safe Air Cargo DC-7BF (N6314J) crashed on climbout from Yakutat Airport after an engine lost power and caught fire, killing the four crew. 14 CFR 91 subpart D was revised in the wake of this accident.<ref>Template:ASN accident</ref>

September 6, 1978: An Advance Aviation Inc. DC-7CF (N244B) was being used to smuggle marijuana when it crashed near Farmerville, Louisiana due to pilot error, killing one of six on board. Thirty-five bales of marijuana were recovered from the wreckage.<ref>Template:ASN accident</ref>

June 22, 1979: A Go Transportation DC-7CF (N357AL) crashed on climbout from Barstow Airport due to overloading and loss of engine power (caused by improper 100 octane fuel), killing one of six crew.<ref>Template:ASN accident</ref>

September 14, 1979: A Butler Aircraft Inc. DC-7 (N4SW) transporting company employees to Medford, Oregon, crashed on the crest of Surveyor Mountain near Klamath Falls, Oregon. The crash, which claimed the 12 occupants aboard, was attributed to the crew's decision to undertake a night flight at low altitude.

1980: An Aero Services Corp. DC-7CF (N8219H) was shot down and crashed in Colombia during a smuggling flight.<ref>Template:ASN accident</ref>

July 27, 1980: A Lambda Air Cargo DC-7CF (CP-1291) burned out on the ground at Trujillo Airport.<ref>Template:ASN accident</ref>

November 28, 1980: A Central Air Service DC-7B (N816D) crashed near Pecos Municipal Airport, Texas, soon after takeoff killing the pilot and co-pilot onboard. The plane entered a steep 90° left bank after takeoff, descended fast with the no. 2 prop feathered and crashed in a field.<ref>Template:ASN accident</ref>

October 9, 1986: A T&G Aviation DC-7C (N5903) ditched off Dakar due to engine problems, killing three of four crew.<ref>Template:ASN accident</ref>

December 8, 1988: A T&G Aviation DC-7CF (N284) was shot down by a SAM-7 missile fired by the Polisario Front and crashed in the Western Sahara, killing the five crew. A second T&G DC-7 (N90984) was also hit, losing an engine, but was able to land safely. Polisario soldiers thought the aircraft were Moroccan C-130s.<ref>Template:ASN accident</ref><ref>Template:ASN accident</ref>

October 1, 1992: A TBM Incorporated DC-7B (N848D) crashed near Union Valley Reservoir, California due to pilot error and poor crew resource management, killing both pilots.<ref>Template:ASN accident</ref>

Surviving aircraftEdit

No DC-7s are in operation today. A small number survive on display or in storage:

N381AA is on display at Epic Flight Academy in New Smyrna Beach, Florida.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

N836D, a DC-7B in flyable condition, is on display at the Sullenberger Aviation Museum in Charlotte, NC
N4887C is on display at the Delta Flight Museum in Atlanta, Georgia.<ref>DC-7 reaches Delta Flight Museum, restored to its former glory, The Points Guy by Zach Honig; Jan 12, 2021</ref>
A DC-7 tail number C-0921 (nicknamed "Charlie 21"), originally flown by United Airlines, was installed at Iliff Preschool in Denver, Colorado in 1971 and is still serving as a kindergarten classroom.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>Template:Unreliable source?

EC-BBT is on display in Gran Canaria.<ref>{{#invoke:citation/CS1|citation

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N51701 is on display at the Pima Air and Space Museum in Tucson, Arizona.<ref>{{#invoke:citation/CS1|citation

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Three Erickson Aero Tanker DC-7s are currently parked at Madras Municipal Airport, Madras, Oregon. N838D (Tanker 60) is planned to join the Erickson Aircraft Collection; N401US (Tanker 62) and N6353C (Tanker 66) are withdrawn from use, awaiting disposal.Template:Citation needed
N777EA, a 1958 DC-7C, is on the market.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>