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{|{{Infobox Aircraft Begin
{{Infobox aircraft
|name = H-12 (Model 48)
|name= R-12/H-12
|image = Bell YH-12B.jpg
|image= File:Bell-48-Helicopter- H-12 -US-Air-Force-Bu-No.-6222.jpg
|caption = YH-12B
|caption= YH-12B
⚫
|type= Military utility helicopter
}}{{Infobox Aircraft Type
⚫
|manufacturer= [[Bell Aircraft]]
⚫
|type = five/eight seat utility helicopter
⚫
|designer=
⚫
|manufacturer = [[Bell Helicopter]]
⚫
|first_flight= [[1946 in aviation|1946]]
⚫
|designer =
|introduction=
⚫
|first flight = [[1946 in aviation|1946]]
|introduced =
|retired=
⚫
|status= Pre-production
|retired =
⚫
|primary_user= [[United States Air Force]]
⚫
|status =pre-series
|more_users=
⚫
|primary user = [[United States Air Force]]
|more users =
|produced=
|number_built= 13<ref name="Pelletier">Pelletier 1992, p. 92.</ref>
|produced =
|number built = 13<ref name="Pelletier">Pelletier 1992, p. 92.</ref>
|unit cost= (YR-12) $175,000<ref name="Pelletier"/>
|developed_from=
|unit cost = (YR-12) $175,000<ref name="Pelletier"/>
|developed from =
|variants=
|variants with their own articles =
}}
}}
|}


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>Pelletier 1992, p. 91.</ref>
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.


==Design and development==
==Design and development==
During 1946, Bell Helicopter began development of a new utility helicopter, the Model 42, much larger than the [[Bell 47|Model 47]], 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''', of which, 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"/>
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"/>


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 10 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 re-designated the '''H-12''', but the results were not satisfactory, there were major problems with the main rotor due to blade weaving and poor rotor governor performance.<ref name="Pelletier"/>
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"/>


==Operational history==
==Operational history==
[[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.]]
No production H-12 aircraft were built but the prototypes and pre-production aircraft were used for various test and development programs.<ref name="Pelletier"/>
No production H-12 aircraft were built but the prototypes and preproduction aircraft were used for various test and development programs.<ref name="Pelletier"/>

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>


==Variants==
==Variants==
Line 37: Line 38:
: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.
;Model 48A
;Model 48A
:The more powerful derivative of the Model 48 with a 600 hp engine and 10 seats. One XR-12B/XH-12B prototype was produced and a pre-production batch of 10 were also built as YR-12B/YH-12Bs
: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
;XR-12
:Prototype, redesignated XH-12, two built.
:Prototype, redesignated XH-12, two built.
Line 43: Line 44:
:Production version, 34 on order canceled.
:Production version, 34 on order canceled.
;XR-12B
;XR-12B
:Prototype with more powerful engine and increased seating, re-designated XH-12B, one built.
:Prototype with more powerful engine and increased seating, redesignated XH-12B, one built.
;YR-12B
;YR-12B
:As XR-12B but with R-1340-55 engines, re-designated YH-12B, 10 built.
:As XR-12B but with R-1340-55 engines, redesignated YH-12B, ten built.
;XH-12
;XH-12
:XR-12 re-designated in 1947.
:XR-12 redesignated in 1947.
;XH-12B
;XH-12B
:XR-12B re-designated in 1947.
:XR-12B redesignated in 1947.
;YH-12B
;YH-12B
:YR-12B re-designated in 1947.<ref name="Pelletier"/>
:YR-12B redesignated in 1947.<ref name="Pelletier"/>
[[File:Bell YH-12B.jpg|thumb|A YH-12B]]


==Operators==
==Operators==
;{{USA}}
;{{USA}}
*[[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 |date=|accessdate=18 October 2014}}</ref>
*[[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>


==Specifications (XR-12B) ==
==Specifications (XR-12B) ==
Line 65: Line 67:
General characteristics
General characteristics
-->
-->
|crew=1
|crew=one
|capacity=9
|capacity=nine
|length ft=56
|length ft=56
|length in=9
|length in=9
|height ft=11
|height ft=11
|height in=3.25
|height in=3.25
|gross weight lb=6,286
|gross weight lb=6286
<!--
<!--
Powerplant
Powerplant
Line 79: Line 81:
|eng1 type=9-cyl. air-cooled radial piston engine
|eng1 type=9-cyl. air-cooled radial piston engine
|eng1 hp=600<!-- prop engines -->
|eng1 hp=600<!-- prop engines -->
|power alt= 119 kW
|rot number=1
|rot number=1
|rot dia m=14.48<!-- helicopters -->
|rot dia m=14.48<!-- helicopters -->
Line 88: Line 89:
-->
-->
|max speed mph=105
|max speed mph=105
|max speed alt= 168 km/h
|cruise speed mph=90
|cruise speed mph=90
|range miles=300
|range miles=300
|ceiling ft=12,800
|ceiling ft=12,800
|ceiling note= service ceiling<br/>
|ceiling note=Service ceiling<br/>
**''' Absolute ceiling:''' {{convert|15,000|ft|m|abbr=on|0}}
**''' Absolute ceiling:''' {{convert|15,000|ft|m|abbr=on|0}}
**'''Hover ceiling:''' {{convert|4,350|ft|m|abbr=on|0}}
**'''Hover ceiling:''' {{convert|4,350|ft|m|abbr=on|0}}
Line 104: Line 104:
*[[Agusta-Bell AB.102]]
*[[Agusta-Bell AB.102]]
|similar aircraft=<!-- similar or comparable aircraft -->
|similar aircraft=<!-- similar or comparable aircraft -->
*[[Sikorsky H-19]]
*[[Sikorsky H-19 Chickasaw]]
|lists=<!-- related lists -->
|lists=<!-- related lists -->
|see also=<!-- other relevant information -->
|see also=<!-- other relevant information -->
Line 114: Line 114:
;Bibliography
;Bibliography
{{Refbegin}}
{{Refbegin}}
* Andrade, John M. ''U.S.Military Aircraft Designation and Serials since 1909''. Leicester, UK: Midland Counties Publications, 1979. ISBN 0-904597-22-9.
* 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.
* ''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.
* Pelletier, A.J. ''Bell Aircraft since 1935.'' London: Putnam & Company Ltd., 1992. {{ISBN|1-55750-056-8}}.
{{Refend}}
{{Refend}}


==External links==
==External links==
{{commons category|Bell 48}}
{{Commons category|Bell 48}}
* [https://books.google.com/books?id=yywDAAAAMBAJ&pg=RA1-PA36&dq=popular+science+1950+ferry+hops&hl=en&ei=nze9TNajH4SAnwe0_Y2KDg&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDIQ6AEwAQ#v=onepage&q&f=true "Copter Ferry Hops To The Front.", Popular Science,'' December 1950, large and detailed article with rare photos]
* [https://books.google.com/books?id=yywDAAAAMBAJ&pg=PA136 Copter Ferry Hops To The Front] – ''Popular Science'' (December 1950)
* [http://www.verticalmag.com/features/the-unknown-helicopter The Unknown Helicopter – Vertical]


{{Bell Aircraft}}
{{Bell Aircraft}}
Line 127: Line 128:


[[Category:Bell aircraft|H-012]]
[[Category:Bell aircraft|H-012]]
[[Category:United States military utility aircraft 1940–1949]]
[[Category:1940s United States military utility aircraft]]
[[Category:United States helicopters 1940–1949]]
[[Category:1940s United States helicopters]]
[[Category:Single-engined piston helicopters]]
[[Category:Single-engined piston helicopters]]
[[Category:Aircraft first flown in 1946]]
[[Category:Single-rotor helicopters]]
[[Category:Aircraft with fixed quad landing gear]]

Latest revision as of 02:53, 27 December 2024

R-12/H-12
YH-12B
General information
TypeMilitary utility helicopter
ManufacturerBell Aircraft
StatusPre-production
Primary userUnited States Air Force
Number built13[1]
History
First flight1946

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]
Journalists and news reported examine a Model 12, which was used to survey the area after a nuclear test in Nevada. April 21, 1952.

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]
A YH-12B

Operators

[edit]
 United States

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
  1. ^ a b c d e f Pelletier 1992, p. 92.
  2. ^ Pelletier 1992, p. 91.
  3. ^ 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.
  4. ^ "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.
[edit]
Wikimedia Commons has media related to Bell 48.
Retrieved from "https://en.wikipedia.org/enwiki/w/index.php?title=Bell_H-12&oldid=1265469063"