Jump to content

Bell H-12: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
general edit
Since it's the unofficial name, it's better down here
 
(46 intermediate revisions by 29 users not shown)
Line 1: Line 1:
{|{{Infobox Aircraft Begin
{{Infobox aircraft
|name = R-12 (Model 48)
|name= R-12/H-12
|image = 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 =
|unit cost= (YR-12) $175,000<ref name="Pelletier"/>
|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>
|developed_from=
|unit cost = (YR-12) $175,000<ref name="Pelletier"/>
|variants=
|developed from = [[Bell 42]]
|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 name="Pelletier"/>


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.
==Development==
During [[1946 in aviation|1946]] Bell Helicopter began development of a new utility helicopter, the [[Bell 42|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]]s and seating 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"/>


==Design and development==
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. Whilst 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"/>
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 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"/>
No production H-12 aircraft were built but the prototypes and pre-production aircraft were used for various test and development programmes.<ref name="Pelletier"/>

==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 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==
''Dats from:''Bell Aircraft since 1935<ref name="Pelletier"/>
;Model 42
;Model 42
:Bells initial foray into the civilian luxury helicopter market, seating 5. Three prototypes were built but serious problems precluded production.
:Bell's initial foray into the civilian luxury helicopter market, seating five. Three prototypes were built but serious problems precluded production.
;Model 48
;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.
: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 Model48 with a 600hp engine and ten seats. One XR-12B / XH-12B prototype was produced and a pre-production batch of ten 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.
;'''R-12A'''
;R-12A
:production version, 34 on order cancelled.
: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, ten 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.
: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 |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>
*[[United States Air Force]]


==Specifications (XR-12B) ==
==Specifications (XR-12B) ==
{{Aircraft specs
{{Aircraft specs
|ref=Bell Aircraft since 1935<ref name="Pelletier"/><!-- reference -->
|ref=''Bell Aircraft since 1935''<ref name="Pelletier"/><!-- reference, you do need page numbers here -->
|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,
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 -->
Line 64: 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 78: 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 -->

|rot number=1
|rot number=1
|rot dia m=14.48<!-- helicopters -->
|rot dia m=14.48<!-- helicopters -->
Line 90: Line 92:
|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 100: Line 102:
|related=<!-- related developments -->
|related=<!-- related developments -->
*[[Bell 47|Bell Model 47]]
*[[Bell 47|Bell Model 47]]
*[[Bell Model 42]]
*[[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 -->

}}
}}

==References==
==References==
;Notes
{{reflist}}
{{Reflist}}
* Andrade, John M. ''U.S.Military Aircraft Designation and Serials since 1909''. Leicester, UK: Midland Counties Publications, 1979. ISBN 0-904597-22-9.
;Bibliography
* The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). London, Orbis Publishing.
{{Refbegin}}
*[http://www.aviastar.org/helicopters_eng/bell_48.php Bell Model 48] retrieved 2-6-2008
* Andrade, John M. ''U.S.Military Aircraft Designation and Serials since 1909''. Leicester, UK: Midland Counties Publications, 1979. {{ISBN|0-904597-22-9}}.
*{{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}}
* ''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}}.
{{Refend}}


==External links==
==External links==
{{commonscat|Bell 48}}
{{Commons category|Bell 48}}
* [http://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'', December 1950, Popular Science] 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}}
{{USAF helicopters}}
{{USAF helicopters}}
{{aviation lists}}

[[Category:United States military utility aircraft 1940–1949]]
[[Category:United States helicopters 1940–1949]]


[[mk:Bell 48]]
[[Category:Bell aircraft|H-012]]
[[Category:1940s United States military utility aircraft]]
[[Category:1940s United States 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]