| 词条 | Douglas C-74 Globemaster | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 释义 |
The Douglas C-74 Globemaster was a United States heavy-lift cargo aircraft built by the Douglas Aircraft Company in Long Beach, California. The aircraft was developed after the Japanese attack on Pearl Harbor. The long distances across the Atlantic and, especially, Pacific oceans to combat areas indicated a need for a transoceanic heavy-lift military transport aircraft. Douglas Aircraft Company responded in 1942 with a giant four-engined design. Development and production modifications issues with the aircraft caused the first flight to be delayed until 5 September 1945, and production was limited to 14 aircraft when the production contract was canceled following V-J Day.[1] Although not produced in large numbers, the C-74 did fill the need for a long-range strategic airlifter, in which the subsequent Douglas C-124 Globemaster II was used by the Air Force for many years. {{TOC limit|limit=2}}Design and developmentThe Douglas Aircraft Company began studies at their Santa Monica division in early 1942 for a transport capable of fulfilling the global logistical needs of the U.S. military. Its "C-74 Project Group" used their company's DC-4 as a basis and concentrated on enlarging its capabilities. The group's design philosophy was to build a "no-frills" aircraft able to accommodate much of the Army's large equipment including light tanks, two {{convert|105|mm|sp=us|adj=on|1}} howitzers with their towing vehicles, two angle bulldozers, and smaller utility vehicles. This became the Douglas Model 415 and a cost-plus contract worth more than $50 million was signed 25 June 1942 for 50 aircraft and one static test article. There were no XC- or YC-74 models produced.[2] This first flight of a C-74 occurred at 1509 hrs. on 5 September 1945 at Long Beach with Ben O. Howard at the controls and lasted 79 minutes.[3] The first C-74, 42-65402, was airborne just two months after it rolled off the assembly line. At the time of its first flight, the C-74 was the largest landplane to enter production, with a maximum weight of 172,000 lb (78,000 kg). It was able to carry 125 soldiers or 48,150 lb (21,840 kg) of cargo over a range of 3,400 mi (5,500 km). Perhaps the most notable feature of the C-74 was its cockpit arrangement with separate canopies over the pilot and copilot; the same arrangement was used for the XB-42 Mixmaster. This arrangement was unpopular with flight crews, however, and the aircraft were retrofitted with a more conventional arrangement. During the life of the aircraft, the radial engines were also upgraded to 3,250 hp (2,424 kW) Pratt & Whitney R-4360-49 engines. The aircraft was 31 feet longer than the C-54 Skymaster, and would be 24 feet longer than the proposed C-118 Liftmaster.[4] The second built, 42-65403, c/n 13914, crashed during flight testing on 5 August 1946 at Torrance, California when it lost a wing during an overload dive test. All four crew bailed out successfully.[5] The fourth aircraft was diverted to a static test article at Wright Field, Ohio and virtually every component was tested to destruction between August 1946 and November 1948. This was done in order to determine the individual components' ability to withstand design loads. The fifth C-74 built was modified to be a prototype for the C-124 Globemaster II, which used the same wing as the C-74, but used a much larger fuselage. This newer aircraft quickly superseded the C-74 in service.[4] Douglas had every intention to adapt the aircraft into a civil airliner once the war ended. Pan American World Airways began negotiations in 1944. Their civilian model would be dubbed a DC-7 by Douglas (Model 415A) and the 'Clipper Type 9' by Pan American. Pan American intended to use the 108-passenger aircraft for international travel between New York, Rio de Janeiro, and other cities. The major difference between the military cargo aircraft and the civil airliner was the non-pressurized fuselage of the military C-74 and the pressurized DC-7. The passenger compartment was to be outfitted with a lounge bar, dining area and sleeping cabins for night flights. In June 1945, an order was placed for 26 DC-7 aircraft.[4] With the need for military aircraft greatly reduced by the end of World War II, the order for 50 military aircraft was canceled in January 1946 after production of only 14 aircraft. This cancellation also ended plans to build an airliner version of the C-74 for the civilian market, as the limited military production run increased the cost per civilian aircraft to over $1,412,000 and Pan American canceled its order. Douglas then canceled the DC-7 designation. The DC-7 designation was later used for a completely different civilian airliner project in the early 1950s, having no relationship to the C-74.[4][6] Operational historyOf the 14 Globemasters built, 11 actually saw operational service. All were used by the United States Army Air Forces Air Transport Command (ATC), and later by the United States Air Force Military Air Transport Service (MATS). The C-74 had a crew of five, including copilot, pilot, radio operator, navigator, and flight engineer. Crew rest quarters were included for long-duration missions. Passageways were provided in the wing to permit the flight engineer to perform servicing and repairs while in flight. It could carry 125 fully equipped troops, 115 litter patients with their medical attendants, or up to {{convert|50000|lb|kg|abbr=on|-2}} of cargo. The cargo bay had twin hoists that could be moved on a rail up and down the bay. They could be used to drop a removable belly section to ease loading of cargoes, reducing the need for specialized cargo handling equipment.[4] The small numbers of C-74s built meant that the aircraft's service was limited, but it gave the Air Force experience with the operation and utility of large transport aircraft. Service introductionThe "C-74 squadron" was activated along with the "C-74 Project" on 5 September 1946. They were attached to the 554th AAF Base Unit located at Memphis Municipal Airport, Tennessee. The 554th was a part of the USAAF Air Transport Command. The C-74 Squadron's mission was:[4]
This project was designed to be a "shakedown" of the aircraft prior to entering operational service. Training of personnel to conduct this test was to have been accomplished by aircrews and technicians initially C-74 trained at Wright Field, Ohio, and also at the Douglas facility in Long Beach, California. Approximately 30 transcontinental flights were planned.[4] The squadron was moved to Morrison Field, Florida in October 1946. This was due to the fact that the runways at Memphis were not stressed to take the large gross weight of the C-74, resulting in some minor cracking to the concrete surface. Operations included two weekly trips from Morrison Field to Albrook Field, Panama using Río Hato Army Air Base as an alternate field.[7] In 1947, the 2nd and 3rd Air Transport Groups (Provisional) were formed and the C-74 was declared operationally ready. Humanitarian missions were flown in 1947 that included flood relief to Florida, and Hurricane relief for the southern area of the U.S.[4] MATS operationsMorrison Field was inactivated on 1 July 1947, and both provisional units were inactivated, the aircraft and support personnel and equipment being reassigned to Brookley Field, Alabama. On 1 June 1948, the Military Air Transport Service (MATS) was formed with the merging of the Air Force's Air Transport Command and the Navy's Naval Air Transport Service. Within MATS, all of the Globemasters were assigned to the Atlantic Division.[4] Once in operational use, C-74s began to be used on scheduled MATS overseas routes though the late 1940s and mid-1950s:[8]
Additionally, logistic support flights for Strategic Air Command (SAC), and Tactical Air Command (TAC) saw the Globemaster in North Africa, the Middle East, Europe, the Caribbean, and within the United States. Two C-74s were used to support the first TAC Republic F-84 Thunderjet flight across the Pacific Ocean to Japan. SAC also continued to use the Globemasters to rotate Boeing B-47 Stratojet Medium Bombardment Groups on temporary duty in England and Morocco as part of their REFLEX operation.[4] Berlin AirliftDuring the Berlin Airlift, a single Globemaster (42-65414)[6] arrived at Rhein-Main Air Base on 14 August 1948 and landed for the first time on 17 August at Berlin's Gatow Airfield in the British sector carrying 20 tons of flour. Over the next six weeks, the Globemaster crew flew 24 missions into the city delivering {{convert|1234000|lb|kg|abbr=on|-2}} of supplies. Several airlift records were set by the crew in 414 during Operation Vittles. On 18 September, Air Force Day, the crew flew six round trips into Berlin hauling a total of {{convert|250000|lb|kg|abbr=on|-2}} of coal setting a new Airlift Task Force utilization record by flying 20 hours during the 24-hour effort.[7][9] During the construction of Tegel Airfield in the French sector of Berlin, large construction equipment was needed to build new runways. But this equipment, including a rock crusher, was too big for even the Globemaster to accommodate. The mission was accomplished by having the equipment cut into pieces by welding torch at Rhein-Main and flown aboard the C-74 into Gatow for reassembly.[7] After six weeks of Vittles flights, the Globemaster returned to Brookley AFB. Reportedly, the Soviet Union complained that the Globemaster could be used as a bomber via the open elevator well. The fact that the runways in Berlin were not stressed for the airlifter's weight and the aircraft was not compatible with the corridor's scheduling were other factors considered for its withdrawal.[7] Support for the Berlin Airlift by the C-74 changed to flying regularly scheduled flights between the U.S. and Western Germany. This mission was called the "Goliath" and was constantly transporting C-54 engines and parts for use in the airlift. Cargo arriving in Western Germany was flown to Berlin in smaller C-47 Skytrain and C-54 Skymaster aircraft.[7] Experience with the Berlin Airlift demonstrated that the new United States Air Force needed a heavy strategic airlift capability, which led to the development of the Douglas C-124 Globemaster II. Korean WarThe invasion of the Republic of Korea by North Korea began another supporting phase of the C-74's career. From 1 July–December 1950, the Globemasters logged over 7,000 hours in flights to Hawaii hauling troops and high priority cargo west toward the Korean War and returning eastward with wounded GIs. During the seven months between July 1950 and January 1951, the Globemasters transported 2,486 patients, 550 passengers, and {{convert|128000|lb|kg|abbr=on|-2}} of cargo from Hickam AFB, Hawaii to the U.S. mainland while hauling just under a million pounds of cargo westward. The C-74s did not fly into Japan, Okinawa or any South Korean airfields. These figures, coupled with the fact that, since 1946, the C-74 had flown over six million miles and 31,000 flying hours without a single injury to crewmen or passengers, give testimony to the Globemaster's reliability.[7] RetirementBy 1952, the C-74 began to experience shortages of spare parts and increasing maintenance problems. It was recognized by late 1954 that the deterioration of the C-74's components was progressing more rapidly than predicted. Plans were made for the eventual retirement of the Air Force's only fleet of Globemasters. In June 1955, the 6th ATS was merged with the 3rd ATS and was flying operational missions with them. On 1 July, the 6th ATS (Heavy) was inactivated and its C-74s and crews were transferred to the 1703rd ATG's 3rd ATS (Heavy). On 1 November 1955, the C-74s were placed in flyable storage at Brookley AFB while the group waited for instructions as to the disposition of the aircraft.[7] During the first three months of 1956, the 11 remaining C-74s were officially removed from the Military Air Transport Service's inventory and were flown one by one to Davis-Monthan AFB, Arizona for long-term storage and disposition. Colonel George S. Cassady, who had accepted the first C-74 for the Air Force and who was by then a Brigadier General, was attending a Continental Division Commander's Conference when he learned of the C-74's last flight. Cassady received special permission to pilot the aircraft on its last flight and on 31 March 1956, flew the last C-74 from Brookley AFB to Davis-Monthan AFB.[7] Most of the C-74s in storage at Davis-Monthan AFB were scrapped in 1965, although four wound up in civilian hands, mostly owned by Aeronaves de Panama (holding company for "Air Systems"). The National Museum of the United States Air Force scrapped the last vestige of Air Force Globemaster Is when they relegated the YC-124C, 48-795 (the prototype of the Globemaster II which had been converted from C-74, 42-65406) to fire-fighting training in 1969.[6]
None of the Aeronaves de Panama C-74s ever came to Panama. Instead they were intended for cattle flights from Copenhagen. For a detailed account of these operations, read Flying Cowboys by Tad Houlihan.
C-74 production
42-65416 through 42-65451 cancelled[4] OperatorsThe following USAAF/USAF units flew the C-74 Globemaster:[8][14]
Specifications (C-74){{aircraft specifications|plane or copter?=plane |jet or prop?=prop |ref=McDonnell Douglas Aircraft since 1920[15] |crew=5 |capacity=125 troops[16] |payload main=48,150 lb[16] |payload alt=21,840 kg |length main=124 ft 2 in |length alt=37.85 m |span main=173 ft 3 in |span alt=52.81 m |height main=43 ft 9 in |height alt=13.34 m |area main=2,510 ft² |area alt=233 m² |empty weight main=86,172 lb |empty weight alt=39,087 kg |loaded weight main=154,128 lb |loaded weight alt=69,911 kg |max takeoff weight main=172,000 lb |max takeoff weight alt=78,000 kg |engine (prop)=Pratt & Whitney R-4360-69 |type of prop=radial engines |number of props=4 |power main=3,250 hp |power alt=2,424 kW |max speed main=328 mph |max speed alt=285 kn, 528 km/h |max speed more=at 10,000 ft (3,050 m) |range main=3,400 mi |range alt=2,950 nmi, 5,470 km |ceiling main=21,300 ft |ceiling alt=6,490 m |climb rate main=2,605 ft/min |climb rate alt=13.2 m/s |loading main=61 lb/ft² |loading alt=300 kg/m² |power/mass main=0.08 hp/lb |power/mass alt=140 W/kg }} See also{{aircontent|related=
|similar aircraft= |lists=
|see also= }} ReferencesNotes1. ^Williams 1995, p. 43. 2. ^Williams 1995, pp. 40–41 3. ^United Press, "Douglas Globemaster Passes First Tests", The San Bernardino Daily Sun, San Bernardino, California, Thursday 6 September 1945, Volume 52, page 4. 4. ^1 2 3 4 5 6 7 8 9 10 Tambini 5. ^"ASN Aircraft accident Douglas C-74 Globemaster I 42-65403, Torrance, California." Aviation-safety.net. Retrieved: 8 May 2010. 6. ^1 2 3 4 5 6 "USAF Globemaster Serial Number Search." cgibin.rcn.com. Retrieved: 26 November 2010. 7. ^1 2 3 4 5 6 7 Williams 1980 8. ^1 Ulanoff 9. ^Williams 1999 10. ^"Accident Description." aviation-safety.net. Retrieved: 26 November 2010. 11. ^1 "Aeronaves de Panama." flightglobal.com. Retrieved: 26 November 2010. 12. ^{{cite web|title=Aviation Photo #0153060: Douglas C-74 Globemaster I - Untitled (Aeronaves de Panama)|url=http://www.airliners.net/photo/Untitled-Aeronaves-de-Panama/Douglas-C-74-Globemaster-I/153060|website=Airliners.net}} 13. ^Herriot 1981, pp. 266–275, 292–309, 336–342. 14. ^USAFHRA Document Search, C-74 Globemaster 15. ^Francillon 1979, p. 408. 16. ^1 Francillon 1979, p. 406. Citations{{Reflist}}Bibliography{{Refbegin}}
External links{{commons category|Douglas C-74 Globemaster}}
6 : United States military transport aircraft 1940–1949|Douglas aircraft|Four-engined tractor aircraft|Low-wing aircraft|Aircraft first flown in 1945|Four-engined piston aircraft |
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