Douglas XCG-17
| XCG-17 | |
|---|---|
| |
| The XCG-17 during towed flight | |
| Role | Assault glider |
| Manufacturer | Douglas Aircraft |
| First flight | June 14, 1944 |
| Primary user | United States Army Air Forces |
| Number built | 1 |
| Developed from | Douglas C-47 Skytrain |
| Type | Prototype |
| Construction number | 4588 |
| Registration | N69030 XA-JID XC-0PS |
| Serial | 41-18496 |
The Douglas XCG-17 was an American assault glider, developed by the conversion of a C-47 Skytrain twin-engine transport during World War II. Although the XCG-17 was successful in testing, the requirement for such a large glider had passed, and no further examples of the type were built; one additional C-47, however, was converted in the field to glider configuration briefly during 1946 for evaluation, but was quickly reconverted to powered status.
Design and development
With the introduction of the Douglas C-54 Skymaster four-engined transport aircraft, the United States Army Air Forces, observing that conventional gliders then in service — such as the Waco CG-4 — would be an inefficient use of the C-54's power and capacity, determined that a requirement existed for a new, much larger assault glider.[1][2] It was determined that the best solution to the requirement was the conversion of the Douglas C-47 Skytrain, already in large-scale production, to meet the requirement. The C-47 could be converted to a glider configuration with minimal alteration to the airframe, and would provide the required capacity.[2]
Trials conducted using a conventional, powered C-47, first conducting ordinary deadstick landings, then being towed by another C-47, indicated that the scheme was feasible.[1] Therefore a C-47-DL was taken in hand for conversion into a glider, which was given the designation XCG-17.[3][4][N 1] The aircraft, formerly a Northwest Airlines DC-3 that had been impressed into military service at the start of World War II,[6][N 2] was modified by the removal of the aircraft's engines; the nacelles, containing the landing gear, remained in place, covered with aerodynamically-profiled hemispherical domes for streamlining, containing fixed weight to compensate for the removal of the engines.[2][6][8] Other equipment, no longer necessary with the conversion to an unpowered configuration, was also removed to save weight;[2] these included the navigator's and radio operator's positions.[6]
Operational history
The conversion, carried out at Clinton County Army Air Field, was completed on June 12, 1944, with the aircraft undergoing its intial flight test shortly thereafter.[6][9] The flight testing of the XCG-17 proved that the aircraft was satisfactory; compared to conventional gliders in service, the aircraft possessed lower stalling and higher towing speeds than conventional gliders, as well as gliding at a significantly shallower angle.[3][10] Tow tests were conducted using a variety of aircraft; the most commonly used configuration was a tandem tow by two C-47s, with the towing aircraft coupled in tandem and the leading aircraft detaching following takeoff.[2] This configuration was dangerous for the "middle" C-47, however,[6] and it was determined that a single C-54 was the optimal tug aircraft.[6][1]
The XCG-17 had a cargo capacity of 15,000 pounds (6,800 kg);[6][8] alternatively, up to 40 fully-equipped troops could be transported, both figures being significantly larger than conventional gliders' capacity.[2] The XCG-17 was also capable of carrying three jeeps in a single load, or alternatively two 105-millimetre (4.1 in) howitzers.[6] Regardless of the aircraft's load, no ballast was required to maintain the aircraft's center of gravity,[2] a trait unique among American assault gliders.[6]
Despite the satisfactory results in testing, however, the aircraft failed the Army's requirement that it be capable of landing on unimproved fields;[6] in addition, by the time the evaluation of the XCG-17 was completed the need for such a large assault glider had passed.[8] The primary role for the glider had been intended as increasing the amount of supplies that could be carries to China over "The Hump"; the war situation had, however, become more favorable and the added capacity an oversized glider would provide was no longer required.[11] No further examples of the type were produced; the prototype, its trials complete, was placed in storage, being ferried to Davis-Monthan Air Force Base for disposal in Augst 1946.[6][9]
In August 1949,[9] the aircraft was sold to Advance Industries, its engines being reinstalled to return the aircraft to powered status in DC-3C configuration.[6][9] Some sources, however, indicate that the XCG-17 was re-converted to C-47 configuration in 1946.[8] Following its restoration to powered status, the aircraft was transferred to Mexico,[6][9] where it remained in civilian service until 1980.[9]
Field conversion
| "Nez Perce" | |
|---|---|
| |
| "Nez Perce" after conversion to glider configuration | |
| Other name(s) | XCG-47; XCG-17 |
| Type | Field converted glider |
| Manufactured | 1946 |
| Serial | 43-16229 |
| First flight | June 17 1946 (as glider) |
| Fate | Reconverted to C-47 |
Although the XCG-17 failed to lead to any production of a C-47 derived glider type, a single C-47 was converted in the field to a glider configuration by the Fifth Air Service Area Command, located at Nichols Field on Luzon in the Philippines, during January 1946.[6][12] Carried out in much the same manner as the XCG-17, the conversion included octagonally-shaped fairings over the engine mountings, with an auxiliary power unit from a B-24 Liberator bomber being installed.[6]
Referred to as "XCG-47" as well as "XCG-17", and named "Nez Perce",[6][12] the aircraft undertook its initial flight following conversion on June 17, 1946, towed by a C-54.[6][12] The flight tests of the field-converted aircraft proved favourable, and an ambitious flight, towing the aircraft from Luzon to Tokyo in Japan, was planned.[6] This flight was intended to prove the suitability of large gliders to act as an "aerial freight train" for regular transport.[6]
The flight, conducted in late June 1946, took 11 hours of flight time and included an overnight stay on Okinawa; covering 1,800 miles (2,900 km), it concluded at Tachikawa Airfield near Tokyo.[6][12] Despite the success of the flight, the "aerial freight train" concept did not catch on; the aircraft had its engines re-fitted in August 1946 and was returned to service as a normal C-47.[6][12]
Operators
Military (as C-47, then XCG-17)
Civilian (as DC-3C)
Specifications (41-18496)
General characteristics
- Crew: Two (Pilot and copilot)
- Capacity: 15,000 pounds (6,800 kg) cargo or 40 troops
- Length: 63 ft 9 in (19.43 m)
- Wingspan: 95 ft 6 in (29.11 m)
- Height: 17 ft (5.2 m)
- Wing area: 987 sq ft (91.7 m2)
- Empty weight: 11,001 lb (4,990 kg)
- Gross weight: 26,000 lb (11,793 kg)
Performance
- Maximum speed: 290 mph (470 km/h, 250 kn) max towing speed
- Cruise speed: 190 mph (305 km/h, 165 kn) gliding speed
- Stall speed: 35 mph (56 km/h, 30 kn)
- Maximum glide ratio: 14:1
- Wing loading: 26.3 lb/sq ft (128 kg/m2)
See also
Related development
- Douglas DC-3
- Douglas C-47 Skytrain
- Douglas AC-47 Spooky
- Douglas C-53 Skytrooper
- Lisunov Li-2
- Showa L2D
Aircraft of comparable role, configuration, and era
Related lists
References
- Notes
- ^ In the U.S. Army Air Forces' designation scheme, the "-DL" suffix indicated an aircraft built at Douglas' Long Beach, California factory.[5]
- ^ A variety of DC-3 series aircraft were impressed into military service at the start of the war. While DC-3 series aircraft constructed for the military were given the designation C-47, impressed aircraft received a variety of designations, including C-47, C-48, C-49, C-50 and C-53, among others. Confusing things further is that the C-53 designation was also assigned to purpose-built military DC-3s, named Skytrooper, that were intended exclusively for personnel transport.[7]
- Citations
- ^ a b c Swanborough and Bowers 1989, p.274.
- ^ a b c d e f g h Taylor 1991, p.151.
- ^ a b Francillon 1988, p.233.
- ^ Davis 1995, p.40.
- ^ Bowers 1986, p.85.
- ^ a b c d e f g h i j k l m n o p q r s t u Day 2001
- ^ Davis 1995, p.31.
- ^ a b c d Grim 2009, p.17.
- ^ a b c d e f g Baugher 2010
- ^ Serling 1997, p.62.
- ^ a b "XCG-17" (in Russian). Airwar.ru. Retrieved 2011-01-20.
- ^ a b c d e Baugher 2011
- ^ Francillon 1988
- Bibliography
- Baugher, Joe (July 18, 2010). "1941 USAAF Serial Numbers (41-13297 to 41-24339)". USAAS-USAAC-USAAF-USAF Aircraft Serial Numbers--1908 to Present. Retrieved 2011-01-21.
- Baugher, Joe (January 15 2011). "1943 USAAF Serial Numbers (43-5109 to 43-52437)". USAAS-USAAC-USAAF-USAF Aircraft Serial Numbers--1908 to Present. Retrieved 2011-01-21.
{{cite web}}: Check date values in:|date=(help) - Bowers, Peter M. (1986). The DC-3: 50 Years of Legendary Flight. Fallbrook, CA: Aero Publishers. ISBN 978-0830681945. Retrieved 2011-01-21.
- Day, Charles L. (2001). "The XCG-17 Glider" (PDF). Research conducted for Silent Ones: WWII Invasion Glider Test and Experiment, Clinton County Army Air Field, Wilmingon, Ohio. Lubbock, TX: Silent Wings Museum. Retrieved 2011-01-20.
{{cite web}}: Italic or bold markup not allowed in:|work=(help) - Francillon, René J. (1988). McDonnell Douglas Aircraft since 1920. Vol. 1. Kirkwood, NY: Putnam Publishing. ISBN 978-0851778273.
- Grim, J. Norman (2009). To Fly the Gentle Giants: The Training of U.S. WW II Glider Pilots. Bloomington, IN: AuthorHouse. ISBN 978-1-4389-0485-6. Retrieved 2011-01-20.
- Serling, Robert J. (1997). When the Airlines Went to War. New York: Kensington Books. ISBN 978-1575662466.
- Swanborough, Gordon (1989). United States Military Aircraft since 1909. Washington, D.C.: Smithsonian Institution Press. ISBN 978-0874748802.
{{cite book}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - Taylor, Michael J.H., ed. (1991). Jane's American Fighting Aircraft of the 20th Century. New York: Mallard Press. ISBN 0-7924-5627-0.
External links
Media related to Douglas XCG-17 at Wikimedia Commons