Bell H-12: Difference between revisions
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{{Infobox aircraft |
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|name |
|name= R-12/H-12 |
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|image |
|image= File:Bell-48-Helicopter- H-12 -US-Air-Force-Bu-No.-6222.jpg |
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|caption |
|caption= YH-12B |
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}}{{Infobox Aircraft Type |
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|retired = |
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|more_users= |
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|produced= |
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|number_built= 13<ref name="Pelletier">Pelletier 1992, p. 92.</ref> |
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|produced = |
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|number built = 13<ref name="Pelletier">{{cite book|last=Pelletier|first=A.J.|title=Bell Aircraft since 1935|publisher=Putnam & Company Ltd.|location=London|date=1992|edition=1st|isbn=1-55750-056--8|oclc=91-66350}}</ref> |
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|developed_from= |
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|variants= |
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|developed from = [[Bell 42]] |
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|variants with their own articles = |
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The '''Bell R-12 (Model 48)''', re-designated as the '''Bell H-12''', was an [[United States|American]] 1940s military utility helicopter built by [[Bell Helicopter]] company.<ref name="Pelletier"/> |
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The '''Bell R-12''' (later redesignated '''H-12'''; company '''Model 48''') was an American 1940s military utility helicopter built by the [[Bell Helicopter]] company.<ref>Pelletier 1992, p. 91.</ref> The design did not go into full production, but over a dozen prototypes were used for various tests and projects. |
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==Development== |
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⚫ | During |
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==Design and development== |
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⚫ | Another enlarged prototype (the |
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⚫ | During 1946, Bell Helicopter began development of a new utility helicopter, the Model 42, much larger than the [[Bell 47|Model 47]], which utilized a scaled-up version of the Model 47's rotor system. Three prototypes were built, but serious rotor problems and complexity of mechanical systems precluded production. The initial Model 42 variant was civilian, but the [[United States Air Force]] ordered the development of its military variant, the '''Model 48'''. Two prototypes were ordered as the '''XR-12''', powered by a single {{convert|540|hp|kW|abbr=on|0}} [[Pratt & Whitney R-1340-AN-1]] [[radial engine]] and featuring seating for five. Of very similar construction to the Model 42, the Model 48 had a shorter rotor mast. A production batch of 34 helicopters was ordered, under the designation R-12A, but cancelled in 1947.<ref name="Pelletier"/> |
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⚫ | Another enlarged prototype (the XR-12B, Model 48A) with seats for eight plus two pilots and a more powerful {{convert|600|hp|kW|abbr=on|0}} Pratt & Whitney R-1340-55 engine was also ordered, followed by ten pre-series YR-12B helicopters, with a glazed nose, instead of the car-like nose of the Model 42 and XR-12. While under flight test the helicopter was redesignated the '''H-12''', but the results were not satisfactory, as there were major problems with the main rotor due to blade weaving and poor rotor governor performance.<ref name="Pelletier"/> |
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==Operational history== |
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[[File:NNSA-NSO-913.jpg|thumb|Journalists and news reported examine a Model 12, which was used to survey the area after a nuclear test in Nevada. April 21, 1952.]] |
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It was unofficially known as the "Fat Boy".<ref>{{cite book |title=Helicopter History and Aerodynamics |date=4 January 1961 |publisher=Headquarters, Air Training Command, United States Air Force |location=Randolph Air Force Base, Texas |page=15 |url=http://catalog.hathitrust.org/Record/100844426 |access-date=27 December 2024}}</ref> |
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==Variants== |
==Variants== |
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''Dats from:''Bell Aircraft since 1935<ref name="Pelletier"/> |
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;Model 42 |
;Model 42 |
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:Bell's initial foray into the civilian luxury helicopter market, seating five. Three prototypes were built but serious problems precluded production. |
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;Model 48 |
;Model 48 |
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:Company designation for the military version of the Model 42, given the designation R-12. Two built as XR-12s and a production contract for 34 was cancelled in 1947. |
:Company designation for the military version of the Model 42, given the designation R-12. Two built as XR-12s and a production contract for 34 was cancelled in 1947. |
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;Model 48A |
;Model 48A |
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:The more powerful derivative of the |
:The more powerful derivative of the Model 48 with a 600 hp engine and ten seats. One XR-12B/XH-12B prototype was produced and a preproduction batch of ten were also built as YR-12B/YH-12Bs |
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;XR-12 |
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:Prototype, redesignated XH-12, two built. |
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;R-12A |
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:Production version, 34 on order canceled. |
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;XR-12B |
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:Prototype with more powerful engine and increased seating, redesignated XH-12B, one built. |
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;YR-12B |
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:As XR-12B but with R-1340-55 engines, redesignated YH-12B, ten built. |
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;XH-12 |
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:XR-12 |
:XR-12 redesignated in 1947. |
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; |
;XH-12B |
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:XR-12B |
:XR-12B redesignated in 1947. |
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; |
;YH-12B |
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:YR-12B |
:YR-12B redesignated in 1947.<ref name="Pelletier"/> |
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[[File:Bell YH-12B.jpg|thumb|A YH-12B]] |
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==Operators== |
==Operators== |
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;{{USA}} |
;{{USA}} |
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*[[United States Air Force]]<ref>{{cite web |url= http://www.aer.ita.br/~bmattos/mundo/helic/bell48.htm |title= Bell Model 48 |publisher= aer.ita.br |access-date= 18 October 2014 |url-status= dead |archive-url= https://web.archive.org/web/20121224014002/http://www.aer.ita.br/~bmattos/mundo/helic/bell48.htm |archive-date= 24 December 2012 }}</ref> |
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*[[United States Air Force]] |
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==Specifications (XR-12B) == |
==Specifications (XR-12B) == |
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{{Aircraft specs |
{{Aircraft specs |
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|ref=Bell Aircraft since 1935<ref name="Pelletier"/><!-- reference --> |
|ref=''Bell Aircraft since 1935''<ref name="Pelletier"/><!-- reference, you do need page numbers here --> |
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|prime units?=imp<!-- imp or kts first for US aircraft, and UK aircraft pre-metrification, |
|prime units?=imp<!-- imp or kts first for US aircraft, and UK aircraft pre-metrification, |
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met(ric) first for all others. You MUST choose a format, or no specifications will show --> |
met(ric) first for all others. You MUST choose a format, or no specifications will show --> |
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General characteristics |
General characteristics |
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--> |
--> |
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|crew= |
|crew=one |
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|capacity= |
|capacity=nine |
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|length ft=56 |
|length ft=56 |
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|length in=9 |
|length in=9 |
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|height ft=11 |
|height ft=11 |
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|height in=3.25 |
|height in=3.25 |
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|gross weight lb= |
|gross weight lb=6286 |
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<!-- |
<!-- |
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Powerplant |
Powerplant |
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|eng1 type=9-cyl. air-cooled radial piston engine |
|eng1 type=9-cyl. air-cooled radial piston engine |
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|eng1 hp=600<!-- prop engines --> |
|eng1 hp=600<!-- prop engines --> |
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|rot number=1 |
|rot number=1 |
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|rot dia m=14.48<!-- helicopters --> |
|rot dia m=14.48<!-- helicopters --> |
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|range miles=300 |
|range miles=300 |
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|ceiling ft=12,800 |
|ceiling ft=12,800 |
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|ceiling note= |
|ceiling note=Service ceiling<br/> |
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**''' Absolute ceiling:''' {{convert|15,000|ft|m|abbr=on|0}} |
**''' Absolute ceiling:''' {{convert|15,000|ft|m|abbr=on|0}} |
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**'''Hover ceiling:''' {{convert|4,350|ft|m|abbr=on|0}} |
**'''Hover ceiling:''' {{convert|4,350|ft|m|abbr=on|0}} |
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|related=<!-- related developments --> |
|related=<!-- related developments --> |
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*[[Bell 47|Bell Model 47]] |
*[[Bell 47|Bell Model 47]] |
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*[[Bell Model 42]] |
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*[[Agusta-Bell AB.102]] |
*[[Agusta-Bell AB.102]] |
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|similar aircraft=<!-- similar or comparable aircraft --> |
|similar aircraft=<!-- similar or comparable aircraft --> |
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*[[Sikorsky H-19]] |
*[[Sikorsky H-19 Chickasaw]] |
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|lists=<!-- related lists --> |
|lists=<!-- related lists --> |
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|see also=<!-- other relevant information --> |
|see also=<!-- other relevant information --> |
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}} |
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==References== |
==References== |
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;Notes |
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{{reflist}} |
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{{Reflist}} |
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;Bibliography |
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{{Refbegin}} |
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*[http://www.aviastar.org/helicopters_eng/bell_48.php Bell Model 48] retrieved 2-6-2008 |
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{{Refend}} |
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==External links== |
==External links== |
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{{ |
{{Commons category|Bell 48}} |
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* [ |
* [https://books.google.com/books?id=yywDAAAAMBAJ&pg=PA136 Copter Ferry Hops To The Front] – ''Popular Science'' (December 1950) |
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* [http://www.verticalmag.com/features/the-unknown-helicopter The Unknown Helicopter – Vertical] |
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{{Bell Aircraft}} |
{{Bell Aircraft}} |
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{{USAF helicopters}} |
{{USAF helicopters}} |
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{{aviation lists}} |
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[[ |
[[Category:Bell aircraft|H-012]] |
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[[Category:Single-engined piston helicopters]] |
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[[Category:Aircraft first flown in 1946]] |
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[[Category:Single-rotor helicopters]] |
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[[Category:Aircraft with fixed quad landing gear]] |
Latest revision as of 02:53, 27 December 2024
R-12/H-12 | |
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General information | |
Type | Military utility helicopter |
Manufacturer | Bell Aircraft |
Status | Pre-production |
Primary user | United States Air Force |
Number built | 13[1] |
History | |
First flight | 1946 |
The Bell R-12 (later redesignated H-12; company Model 48) was an American 1940s military utility helicopter built by the Bell Helicopter company.[2] The design did not go into full production, but over a dozen prototypes were used for various tests and projects.
Design and development
[edit]During 1946, Bell Helicopter began development of a new utility helicopter, the Model 42, much larger than the Model 47, which utilized a scaled-up version of the Model 47's rotor system. Three prototypes were built, but serious rotor problems and complexity of mechanical systems precluded production. The initial Model 42 variant was civilian, but the United States Air Force ordered the development of its military variant, the Model 48. Two prototypes were ordered as the XR-12, powered by a single 540 hp (403 kW) Pratt & Whitney R-1340-AN-1 radial engine and featuring seating for five. Of very similar construction to the Model 42, the Model 48 had a shorter rotor mast. A production batch of 34 helicopters was ordered, under the designation R-12A, but cancelled in 1947.[1]
Another enlarged prototype (the XR-12B, Model 48A) with seats for eight plus two pilots and a more powerful 600 hp (447 kW) Pratt & Whitney R-1340-55 engine was also ordered, followed by ten pre-series YR-12B helicopters, with a glazed nose, instead of the car-like nose of the Model 42 and XR-12. While under flight test the helicopter was redesignated the H-12, but the results were not satisfactory, as there were major problems with the main rotor due to blade weaving and poor rotor governor performance.[1]
Operational history
[edit]No production H-12 aircraft were built but the prototypes and preproduction aircraft were used for various test and development programs.[1]
It was unofficially known as the "Fat Boy".[3]
Variants
[edit]- Model 42
- Bell's initial foray into the civilian luxury helicopter market, seating five. Three prototypes were built but serious problems precluded production.
- Model 48
- Company designation for the military version of the Model 42, given the designation R-12. Two built as XR-12s and a production contract for 34 was cancelled in 1947.
- Model 48A
- The more powerful derivative of the Model 48 with a 600 hp engine and ten seats. One XR-12B/XH-12B prototype was produced and a preproduction batch of ten were also built as YR-12B/YH-12Bs
- XR-12
- Prototype, redesignated XH-12, two built.
- R-12A
- Production version, 34 on order canceled.
- XR-12B
- Prototype with more powerful engine and increased seating, redesignated XH-12B, one built.
- YR-12B
- As XR-12B but with R-1340-55 engines, redesignated YH-12B, ten built.
- XH-12
- XR-12 redesignated in 1947.
- XH-12B
- XR-12B redesignated in 1947.
- YH-12B
- YR-12B redesignated in 1947.[1]
Operators
[edit]Specifications (XR-12B)
[edit]Data from Bell Aircraft since 1935[1]
General characteristics
- Crew: one
- Capacity: nine
- Length: 56 ft 9 in (17.30 m)
- Height: 11 ft 3.25 in (3.4354 m)
- Gross weight: 6,286 lb (2,851 kg)
- Powerplant: 1 × Pratt & Whitney R-1340-55 Wasp 9-cyl. air-cooled radial piston engine, 600 hp (450 kW)
- Main rotor diameter: 47 ft 6 in (14.48 m)
- Main rotor area: 1,772 sq ft (164.6 m2)
Performance
- Maximum speed: 105 mph (169 km/h, 91 kn)
- Cruise speed: 90 mph (140 km/h, 78 kn)
- Range: 300 mi (480 km, 260 nmi)
- Service ceiling: 12,800 ft (3,900 m) Service ceiling
- Absolute ceiling: 15,000 ft (4,572 m)
- Hover ceiling: 4,350 ft (1,326 m)
See also
[edit]Related development
Aircraft of comparable role, configuration, and era
References
[edit]- Notes
- ^ a b c d e f Pelletier 1992, p. 92.
- ^ Pelletier 1992, p. 91.
- ^ Helicopter History and Aerodynamics. Randolph Air Force Base, Texas: Headquarters, Air Training Command, United States Air Force. 4 January 1961. p. 15. Retrieved 27 December 2024.
- ^ "Bell Model 48". aer.ita.br. Archived from the original on 24 December 2012. Retrieved 18 October 2014.
- Bibliography
- Andrade, John M. U.S.Military Aircraft Designation and Serials since 1909. Leicester, UK: Midland Counties Publications, 1979. ISBN 0-904597-22-9.
- The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985). London, Orbis Publishing, 1985.
- Pelletier, A.J. Bell Aircraft since 1935. London: Putnam & Company Ltd., 1992. ISBN 1-55750-056-8.
External links
[edit]- Copter Ferry Hops To The Front – Popular Science (December 1950)
- The Unknown Helicopter – Vertical