Bell H-12: Difference between revisions

R-12/H-12
R-12/H-12
	YH-12B
General information
Type	Military utility helicopter
Manufacturer	Bell Aircraft
Status	Pre-production
Primary user	United States Air Force
Number built	13
History
First flight	1946

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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.^[2] The design did not go into full production, but over a dozen prototypes were used for various tests and projects.

Design and development

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

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

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

United States

United States Air Force^[4]

Specifications (XR-12B)

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)

References

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

Copter Ferry Hops To The Front – Popular Science (December 1950)
The Unknown Helicopter – Vertical

[Pelletier-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.

[1]

[2]

[3]

[4]

@@ 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)''' 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 helicopter, much larger, than [[Bell 47|Model 47]]. It was partly basing upon its construction, first of all, a rotor system, and was basically a scaled-up version of Model 47. The basic variant was civilian [[Bell Model 42|Model 42]], but the [[United States Air Force]] got interested in the design and ordered development of its military variant, '''Model 48'''. Two prototypes were ordered as the '''XR-12'''. It was powered by a 540&nbsp;hp [[Pratt & Whitney R-1340]]-AN-1 [[radial engine]] and seated five. A production batch of 34 helicopters was ordered, under a designation '''R-12A''', but it was cancelled afterwards. Another enlarged prototype (the '''XR-12B''', Model 48A) with seats for eight and a more powerful 600&nbsp;hp R-1340-55 engine was also ordered. It was followed by ten pre-series helicopters '''YR-12B''', with a redesigned cabin, with a glazed nose, instead of car-like nose<ref>[http://www.aviastar.org/helicopters_eng/bell_48.php Bell Model 48]</ref>. With a change in designation system the helicopter was re-designated the '''H-12'''. Test were not satisfactory, there were initially problems with the main rotor, and none were ordered.<ref name="Pelletier"/>
+==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]], 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"/>
+==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==
+;Model 42
-''Dats from:''Bell Aircraft since 1935<ref name="Pelletier"/>
+:Bell's initial foray into the civilian luxury helicopter market, seating five. Three prototypes were built but serious problems precluded production.
-;'''XR-12''':prototype, redesignated XH-12, two built.
+;Model 48
-;'''R-12A''':production version, 34 on order cancelled.
+: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.
-;'''XR-12B''':prototype with more powerful engine and increased seating, re-designated XH-12B, one built.
+;Model 48A
-;'''YR-12B''':as XR-12B but with R-1340-55 engines, re-designated YH-12B, ten built.
+: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
-;'''XH-12''':XR-12 re-designated in 1947.
+;XR-12
-;'''XH-12B''':XR-12B re-designated in 1947.
+:Prototype, redesignated XH-12, two built.
-;'''YH-12B''':YR-12B re-designated in 1947.
+;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.<ref name="Pelletier"/>
+[[File:Bell YH-12B.jpg|thumb|A YH-12B]]
 ==Operators==
 ;{{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) ==
 {{Aircraft specs
-|ref=Bell Aircraft since 1935<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><!-- 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,
 met(ric) first for all others. You MUST choose a format, or no specifications will show -->
@@ Line 47: / Line 67: @@
         General characteristics
 -->
-|crew=1
+|crew=one
-|capacity=9
+|capacity=nine
 |length ft=56
 |length in=9
 |height ft=11
 |height in=3.25
-|gross weight lb=6,286
+|gross weight lb=6286
 <!--
         Powerplant
@@ Line 61: / Line 81: @@
 |eng1 type=9-cyl. air-cooled radial piston engine
 |eng1 hp=600<!-- prop engines -->
 |rot number=1
 |rot dia m=14.48<!-- helicopters -->
@@ Line 73: / Line 92: @@
 |range miles=300
 |ceiling ft=12,800
-|ceiling note= service ceiling<br/>
+|ceiling note=Service ceiling<br/>
 **''' Absolute ceiling:''' {{convert|15,000|ft|m|abbr=on|0}}
 **'''Hover ceiling:''' {{convert|4,350|ft|m|abbr=on|0}}
@@ Line 83: / Line 102: @@
 |related=<!-- related developments -->
 *[[Bell 47|Bell Model 47]]
-*[[Bell Model 42]]
 *[[Agusta-Bell AB.102]]
 |similar aircraft=<!-- similar or comparable aircraft -->
-*[[Sikorsky H-19]]
+*[[Sikorsky H-19 Chickasaw]]
 |lists=<!-- related lists -->
 |see also=<!-- other relevant information -->
 }}
 ==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}}.
+* ''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==
-{{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}}
 {{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]]

v t e Bell Aircraft and Bell Helicopter/Bell Textron aircraft
Manufacturer designations	1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31¹ 32 33 34 35 36 37 38 39 (I) 39 (II) 40 41 42 43 44 45 46 47 J 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70–100¹ 101 102 103 104 105 106 107¹ 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131–199¹ 200 201 202¹ 203¹ 204 205 206 207 208 209 210 211 212 213¹ 214 214ST 215¹ 216 217¹ 218¹ 219¹ 220¹ 221¹ 222 223–229¹ 230 231–248¹ 249 250–300¹ 301 302–308¹ 309 310–359¹ 360 361–399¹ 400 401–405¹ 406 407 408¹ 409 410¹ 411¹ 412 413¹ 414¹ 415¹ 416¹ 417 418–426¹ 427 428¹ 429 430 431–439¹ 440 441¹ 442¹ 443¹ 444¹ 445 446¹ 447¹ 448¹ 449 550–504¹ 505 506–524¹ 525 526–532¹ 533 534–539¹ 540 541–547¹ 548 549–575¹ 576 577–582¹ 583 846–598¹ 599 600–608¹ 609 610–645¹ 646 647–679¹ 680 681–910¹ 911 912–917¹ 918 D-188 D-255 D-292
Fighter aircraft	YFM-1 P-39 XFL P-59 P-63 P-76 XP-77 XP-83
Target drones	PQM-56
Attack helicopters	207 Bell AH-1 Singles Twins AH-1Z 309 YAH-63 360
Observation and utility helicopters	H-13 H-13J UH-1 UH-1N UH-1Y TH-57 OH-58 TH-67 ARH-70
Commercial helicopters	47 47J 204 205 206 210 212 214 214ST 222 230 407 412 427 429 430 505 525
Tiltrotors	V-22 V-247 V-280 AW609 TR918 QTR
UAVs	MQ-8C
Non-production helicopters	400 417 440
Experimental aircraft	ATV 201 533 D-188 D-255 D-292 FCX-001 L-39 LLRV/LLTV X-1 X-2 X-5 X-14 X-16 X-22 XF-109 XP-52 XV-3 XV-15
Names	Airabonita Airacobra Airacomet Airacuda Arapaho BigLifter Cobra Creek Eagle Eye Fire Scout GlobalRanger Huey HueyCobra Invictus Iroquois JetRanger Jet Ranger X Kingcobra KingCobra Kiowa LongRanger Osprey Quad TiltRotor Ranger Sea Cobra Sea Ranger Sioux Sioux Scout SuperCobra Super Huey Super Transporter Twin Huey TwinRanger Valor Venom Vigilant Viper Zulu Cobra
¹ Unknown/not assigned