The World’s Greatest Aircraft

By diligent product development, Bell Helicopter has turned a smallutility machine of the mid-1950s into a host of offspring, some carrying apayload almost double the laden weight of their ancestor. As a result

the numbers built exceed those of any aircraft since 1945 except for theAntonov An-2.

No single name, number or designation really covers th is family,except for the colloquial ‘Huey’, which i s suff ic ient ly loose to fit thelot. Yet can it really link a 700-hp (522-kW) six -seater with a 3,250-hp(2425-kW) 20-seater, and take in the fighter -like Cobra family on t h eway? Almost the only thing they have in common i s that the i rdistinctive rotor slap can be heard rumbling and thumping forseveral minutes before the machine finally comes into view, andeven here there i s an exception, the new Model 412 with i t s smal lerand quieter four-blade main rotor.

This remarkable family, which looks set to notch up 15,000 sales,began with the issue of a document describing Support System443L in early 1955. Experience in t h e Korean War had underscoredthe value of the helicopter in a land battle, not so m u c h as a carr ierof weapons but as a versatile utility transport system that canbring food and ammunition to a front -line outpost and take out thecasualties. As millions know from the M.A.S.H. TV serial, BellHelicopter was in on the ground floor with this work with i t sModel 47; but t h i s had l i t t l e more than 200 hp (149 kW) a n d wasvery limited in what it could carry. The US Army specification of1955 looked to about three times th i s power, but in a neater andmore modern machine than the Sikorsky S-55.

No t surprisingly, Be l l won the US Army competition and in June1955 was awarded a contract for three prototypes designated XH-40.Bell ’s designation was Model 204, and the design team underBartram Kel ley was pleased with i t s clean and efficient offering. Sotoo was the engine supplier, Avco Lycoming. which had soughtGerman engineers in order to underpin i t s new move into t h e fieldof turbine power. The T53, a free - turbine shaft engine of some700 hp (522 kW), was the f i r s t U S design by a team headed by DrAnselm Franz, who during the war had masterminded t h e Jumo 004programme which produced engines for the Messerschmitt M e 262,Arado Ar 234 and many other aircraft. The T53 was a conservativeengine which promised to mature rapidly, whilst offering the basicturbine advantages of much better rat io of power to weight andbulk, greatly improved reliability, reduced fire r isk, the ability torun on a wide range of fuels, and the elimination of complicatedand power -absorbing cooling systems.

This beautiful picture shows both types of Huey in current front-line use by the USMarine Corps. The utility transport Iroquois is no. 151271, a UH-1E serving with theHMS-24 (Headquarter and Maintenance Sqn), based at Kaneohe Bay, Hawaii. In therear is an AH-1J SeaCobra of the same unit, with tail code M I .

The World's G

Typical of the first Hueyvariantto be builtin large numbers, this HU-1B (after1962redesignated UH-16) was no. 64-13912,one of 1,014of this model procured by theUS Army. It is shown serving with the 1stAviation Battalion, 1st Infantry Division(whose badge appears on the fin), withbulldog badge in 1967.

One of the early customers of the ItalianAgusta company for licensed Bell Hueyhellcopten was the OL (Austrian airforce) which used this AB 205 in the 3rdHelo Wing (F1iegerregiment)at Linz in thelate 1960s. Subsequently bothFliegerregiments 1 and 3 re-equippedwith the licensed win-engined AB 212.

A particular advantage of the light and compact turboshaftengine was that it could be installed right next to the gearboxunder the main rotor, where it was readily accessible yet did notencroach on the accommodation in the cabin. Compared with theS-55 the XH-40 had roughly the same cabin volume, but the cabinwas wider and more efficient, the pilot and five passengers being allon the same low floor level, with side doors at a convenient height.For minimum weight the fuselage had a tadpole configuration. thelarge cabin section being joined to a slim boom carrying the fin andtail rotor. The main rotor was rather like a scaled -up and modern -ized Model 47 rotor, with two blades made wholly of light alloy,with an extruded spar, and with the company's patented stabilizerbar set at 90" to the blades. Engineering test pilot Floyd Carlsonmade the f i rs t flights a t Fort Worth on 20 and 22 October 1956, andno severe problems were encountered.

By this time Bell was busy with a service -test batch of six YH-40s.These had the pre-production T53-L-1A engine of 700 hp (522 kW),a cabin 12 in (305 mm) longer to accommodate four stretchers(l i t ters) and a wider crew door, as well as greater ground clearanceand modified flight controls. N ine pre-production machines thenfollowed, and it was their revised designation of HU-1A that gaver ise to the universal name 'Huey', used far more often than t h e USArmy official name of Iroquois. F i r s t delivery took place on 30 June1959. The enginc was by th is t ime cleared to give 860 shp (642 kW):but it was flat -rated at 770 shp (574 kW) in all early Iroquois to give

constant output in hot and high conditions. Many early HU-1Aswere armed with various mixes of guns and rockets, while 14 weredual trainers with provision for real and simulated instrumentinstruction.

In 1959 work began on the YHU-lB, with the 960-shp (716-kW)T53-5 or 1,100-shp (821-kW) T53-11. This jump in power madepossible a major increase in gross weight, from 5,800 lb (2631 kg) to8,500 lb (3856 kg), and to transmit it the main -rotor blades wereredesigned with increased chord and a honeycomb filling af t of thespar. The cabin was again enlarged to seat t h e pilot and eightpassengers in three rows, or a crew of two and seven armed troops,o r three stretchers, two sitting casualties and a medic, or a cargoload of 3,000 lb (1361 kg). This was roughly double t h e load lifted bythe XH-40. The HU-1B f i r s t flew in 1960, and many of t h e productionmodels had various armament schemes including two 30-mmcannon, two packs each of 24 rockets, quadruple 7.62-mm (0.3-in)machine -guns or a 40-mm grenade -launcher.

Increased accommodationIn 1962 t h e tri -service designation system changed t h e HU-1into

the UH-1, but without making the slightest dent in usage of thepopular name. By t h i s time Be l l was well advanced in flight tr ialswith the YUH-lD, which capitalized on the power of the L-11engineto drive a 48-ft (14.63-m) rotor and lift an altogether bigger fuselage

No information is available on the owner of this early Bell 204. though it wasphotographed in the Fort Worth area. This original production model, based on the USArmy H-40 of the 195Os, had a maximum laden weight much less than the usefulpayload of today's Model 214ST. Early Model 204s were six-seaters.

During the war in South-East Asia most US Army Hueys were painted plain khaki-brown, without insignia, but the South Vietnam airforce Hueys were painted grey anddid carry red/yellow/blue national markings. This UH-1H. pictured on a combatmission in August 1971, was one of hundreds lefi after the US withdrew.

Navy BuAer no. 158284 is one of a batchof 204 UH-1N-BF helicopters purchasedby the US Navy (some on behalf of th@Marine Corps). A standard 14-seat multi-role transport, this example has rescat?gear and serves at Naval Air StationAgana, on Guam The UH-1N is thestandard Navy local base rescuehelicopter.

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able to accommodate the pilot and 12 troops, or six stretchers and amedic, or 4,000 Ib (1814 kg) of freight. This was t h e f i r s t of t h estretched Model 205 family, of which 6,000 were built in the f i r s t 10years. Bell also continued to build more and more variants of t h eoriginal Model 204 series, as noted in the variants l is t , but by theearly 1970s these had almost completely given way to t h e morecapable Modcl 205 family.

From 1961 Agusta SpA in Italy had been busy producing t h eAB.204 licensed version for many civi l and military customers,including models with the Rolls -Royce Gnome (licensed T58) or t h eparent T58 engine. Del iver ies to the Italian and Spanish naviesincluded the AB.204AS with Ekco radar. autostabilization andautohover systems and many search and attack devices, as well astwo Mk 44 torpedoes for anti -submarine operations. In Japan Fujibuilt large numbers for many customers using Kawasaki -built T53engines. In 1970 Fuji began testing a high-speed winged develop -ment, t he XhfH. Thls was one of many attempts to overcome thefirst -generation H u e y 's only real drawback, i t s inability to flyfaster than about 127 mph (204 km/h).

Bell concentrated instead on sheer capability inutility roles, andwith t h e commercial Model 205A, basically a UH-1D but with the1,400-shp (1044-kW)"53-13 and f i r s t flown in 1963. the slung payloadwent up to 5,000 Ib (2268 kg), as an alternat ive to a pilot and 14passengers! By t h e mid-1960s the T53-13 was t h e usual engine and itresul ted in a designation of UH-1H for t h e U S military models.

The biggest single expolt order gained by any type of helicopter was for 202 Bell AH-1JCobras, with TOW capability, for what in 1974 (when deliveries began) was theKingdom of Iran. All had been delivered at the time of the revolution and they havesince been heavily engaged in the war of attrition agalnst Iraq.

This UH-IN Iroquois, Navy BuAer no.158277, was bought as a standardmachine and transferred to the MarineCorps, where it was converted into aVH-1N for VIP staff transportation. No.158278 was similarly converted, and sixHueys were built as VH-INS. They haveluxurious accommodation and extracommunications.

Agusta produced AB.205~in various forms, and 118 UH-1Hs wereassembled, and incrcasingly constructed, in Taiwan.

In August 1962 Hell f lew t h e Model 533, a YUH-1B grosslymodified under U S Army contract as a high -speed research vehicle.Fitted with a swept wing and two small je ts it reached 254 mph(409 km!h) and pulled tight tu rns at over 200 mph (322 km/h). In1969, ref i t ted with two 3,300-lb (1497 -kg) thrust J60 (JT12A) jets, itset a helicopter spccd record at a remarkable 316 mph (509 km/h).This taught Bell a great deal. much of which was put to use in themid-1960s when it was obvious that a specially designcd helicoptergunship was needed in Vietnam. Bell had previously flown a gun-ship Model 47, the Sioux Scout of 1963, but t h e Huey was theprefcrred basis for a production machine. The resu l t was the f i r s tAH-IG HueyCobra, in which t h e popular name was accepted aspart o f t h e official one.

Basically a UH-lC, which in 1965 introduced a new rotor, theAH-1G had a totally new fuselage only 36 in (914 mm) wide. withstepped tandem cockpits for a gunnerjobserver in the nose and thepilot behind and above, both under a fighter -like canopy. The rotorwas t h e Model 540 type, with new wide blades of 27-in (686-mm)chord, with a 'door hinge' root. generating much more lift thanbefore and, by flying at reduced angles, freeing t h e machine fromprevious speed restrictions. The f i rs t AH-1G flew on 7 September1965, as the f i rst of a new family. t h e Model 209. Problems weresurprisingly few. and by March 1966 thc AH -l(; was in full pro-

BuAer no. 159228 is a twin-engined AH-lJ SeaCobra of the US Marine Corps, with thepowerful General Electric M197 gun. It is seen on special trials atthe Naval WeaponsCenter, China lake, California, in March 1980. It was engaged in trials with AIM-91Sidewinder self-defence AAMs, which were fired against target RPVs.

duction. T h e U S Army was s t i l l trying to achieve success with t h eextremely complex Lockheed AH-56A Cheyenne, but it saw in t h eCobra something it could get to Vietnam quickly. L i t t l e did Bel lknow the very advanced Cheyenne would grind t o a halt, and theCobra would have thc gunship market to i t s e l f for the next 18 years!

A wealth of possible equipment and armament f i t s was eventuallyproduced for the HueyCobra, the first being Emerson’s TAT-102Aturret fixed under the nose and fitted with two 7.62-mm (0.3-in)machine -guns or six -barrel Miniguns. The more common installa -tion became the M28 armament system comprising either twoMiniguns, two M129 40-mm grenade -launchers each w i t h 300projectiles, or one of each. On stub wings could be hung fourlaunchers for 76 rockets, or pods of larger rockets, or Miniguns or30-mm cannon, or, in later years, the quadruple TOW miss i leinstallation, with the Hughes stabilized sight in the nose. Over theyears in Vietnam t h e HueyCobra became more commonly knownas the Snake, working in partnership with the Loach (OH-6ACayuse) to form a deadly front -l ine team that for the f i r s t t ime usedthe helicopter as a t rue front -line battle weapon.

Deliveries of the original AH-1G reached 1,126 by late 1971. TheU S Marine Corps bought the AH-1J Seacobra, which used the1,800-shp (1343-kW) PT6T (T400) coupled twin turbine. ThisCanadian engine was also selected at the same time for a regularHuey version, the UH-1N (Canadian CH-135), the f irst members ofthe Model 212 or Twin Two -Twelve family. Should either powersection fail, the remaining ha l f can be instantly uprated to over1,000 shp (746 kW), giving full twin -engine safety. The ScaCobrawas later developed in to today’s AH-lT, with a longer body, morepower, uprated dynamic parts and TOW or B l l f i r e missiles. Likeall the latest Cobras the ch in tu r re t i s f i t ted with t h e M197 20-mmgun, which has three of the six harrels of the M61 fighter aircraftgun. Since 1980 Bell has been flying an AH-1T with two GeneralElectr ic T700 engines giving a combined power of 3,380 hp (2521kW). This i s expected to become t h e standard power of fu tu reCobras, which are strengthened to take it, along with manyrefinements to enable them to survive even better in the face ofhostile fire. Meanwhile, by 1983 the U S Army had completelyrcbuilt i t s Cobras to bring over 1,000 up to various AH-1S standardswith largely ncw structure and systems, angular flat -plate cano -pies, a single 7’53 uprated to 1,800 shp (1343 kW), and completelyupgraded avionics and weapons.

Revised Model 212Large numbers of Twin Two-Twelves are in use all over t h e world

in both military and civi l roles. One batch of 10, with extremely fullequipment, was supplied to China to support energy and naturalresource development. In August 1979 flight development began ofthe Model 412, a Model 212 with an advanced four -blade mainrotor which improves performance whilst reducing noise andvibration. It i s se l l i ng well in military and civil forms, and is alsobeing built by Agusta as t h e AB.412, with the emphasis on multi -role military variants.

A move towards further increase in basic capability came in 1967with the HueyTug. powered by a Lycoming T55 rated at 2,650 shp

The Model 212 Twin Two-Twelve has almost the same structure as the UH-1H andrelated models, but is powered by the PT6T-3B engine which hastwo separate powersections, giving twin-engine safety. The Twin Two-Twelve commercial version, asseen here. was certificated in 1970 to carrv a 5.000.lb (2268-kal load.

(1977 kW), reduced to a steady 2,000 shp (1492 kW) to match t h elimit o f t h e transmission to t h e Model 540 door -hinge rotor. Thisled to the Kingcobra gunship, not built in numbers, and the Model214 HueyPlus! with the 2,850-shp (2126 kW) T55. Iran L d e r theShah snapped up 287 Advanced 214As, one of which soon set worldclass records for altitude and rate of climb. This in turn l e d to abatch of Model 214B BigLifters, leading to today’s Mvdel 214ST,t h e suffix meaning Stretched Twin. Today the top end of the ent i reHuey range, this great machine looks good with i t s larger andmore streamlined fuselage, on top of which i s the power packagecontaining two General Electr ic CT7-2A engines of 1,625 shp(1212 kW) each. They drive a new transmission and rotor system,the main rotor having very advanced glassfibre blades of 52-ft(15.85-m) diameter, good enough for gross weights up to 17,500 Ih(7938 kW) and with the ability to hoist slung loads up to 9.000 lb(4082 kg), or getting on for double t h e laden weight of t h e originalXH-40! In offshore operations, where the passengers are extremelyweighty, i t i s s t i l l possible to fly a pilot, co-pilot and 18 passengersover sectors exceeding ,400 miles (644 km).

Today Be l l Helicopter has so many products and so many newprojects that the Huey i s j u s t one of a wide range of product l ines.But i t i s very doubtful any of these wil l rival the total numbers ofHueys, and they have some way to go yet. Even the old Model 206has had to be put back on the l ine to fulfil an order for 25 for Turkey:and Fuji and Agusta are s t i l l hard at it, while Be l l concentrates ont h e la tes t Cobras, Model 412s and Model 214s.

slightly reduced diameter. Thisgives small improvements in flight performance,notably in rate of climb, but the big advantage is less vibration.

2269

BellModel 209

Spurred by the demands of the Vietnam War, Bell AH-1G HueyCobra helicopters werebought in quantities almost as large as the basic UH-ID and UH-1H from fiscal year1966 onwards (the year does not appear in the serial number). This early example hasthe standard M28 chin turret with an M134 Minigun with 4,000 rounds of 7.62-mm(0.3-in) ammunition and an M129 grenade -launcher with 300 grenades of 40-mm(1.58-in) calibre. It is also shown with pairs of M157 (seven 2.75-in170-mm) and M159C(19 2.7!3n/7&mm) rocket-launchers.

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SpecificationBell Model 209 AH-1S- Performance: maximum speed varies from 207 mph I333 kmih) to 141 mph(227 km/h) depending on equipment fit; range a t sea leve l w i th maximum f u e l andeight per cent reserves 315 miles (507 km)Weights: empty 5,479 Ib (2939 kg); maximum take -off 10,000 Ib (4535 L-v)..a,

Dimensions: main rotor diameter 44 ft 0 in (13.41 m) ur, in AH-l'r family, 48 ft 0 in(14.63 m); fuselage length 44 ft 7 in (13.59 m) or. in AH -lT, 48 ft 2 In (14.68 m), heightover tai l rotor 13 ft 6& in (4.12 mj; main ro tor disc area 1,520.5 sq ft (1."1.26 m 2) or,in AH-lT, 1,809.6 s q ft (168.1 rn')Armament: eight TOW missi les o n outboard wing pylons, with pods inboardhousing groups of seven or 19 of any of five types of 2.75 -in (69.9-mm) rocket;General Electr ic turret under nose wi th M197 20-mm three -barrel gun (a1ternativesare 30-mm gun or combined 7.62-mm/0.3 -in Minigun plus 40-mm grenadc~launcher)

BellHuey variantsMode1204 (XH.40): three prototypes 15544591

YH-40: imp-wed development nachlnes (56-6723128)UH-1A: lnlttal productlon with 770-shpi547 -kWiT53-1A. later 9fiC-shp(716 -kW, 753-5, total 181TH-1A:dualtrainervarlant. total 14UH-1B:stretchedmodelwlthnlneseats. 1.100~shpl821 -kWtT53 -ll.newmaln rotor,oftenarmed kame dcslynatlon), total 1,014UH-IC: revlscd fuel tankage wlthgreatercapacltyand Improved cabln. newType 540rotor: total767UH;lD: furtherenlargedcabln. T53-11 englne.Iota. 2,008, plusvartous exponsand 352 licence -builtby DornierUH-1E: armedzssauit Todel for US Marlnesw1thT53 -11 and (retrofit) lype540 rotor. total1a?I"&

TH-1E: dual tralner; total20UH-IF: USAFICBM sltesupponrnodelwith1.272 -shpl949 -kWtT58 -3enytneand 1 1 seats.total 120TH-IF: USAF tralner, total26AH-1G:flrstHdeyCobra. total I.119TH.lG: dualtratnerconversionsUH-IH: U W l D v ~ t h1,400 shp(1044 -kW)T53 -13, total5.435plusexportsandl 18bulltlnTatwanEH-1H: ECMlEIlntconverslonsof UH-1H

HH-1H: baserescue USAFmodcI. total30AH-1J: basic SeaCoSra, !otal84plus 2021o.lrsnHH-1K: US Navysearchlrescuc. totdl27TH-1L: USNavytr?lner, tolo190UH-1L: US Navy u t ~ l ~ t y ,total8UH-1M: US Army night attackconwrslonsUH-1N: twlnTwo -Twelve u'tlt'y model wlth upto l5seats. totalUSAF79. US'.iavy/Mdr!nes221VH-1N: US MartneVlPtranspons, someconversloisplus newbulld. total6UH-1P: psy -warconverslonsoiUH -lF,unknown nu.nberAH-1Cl: Improved rebulldsof AH -IGAH.1R: uprated AH 1G 11,800 -shp/1343 -kW153 7031 conversionsAH-IS: series of progreswe Improvements ofAH-1G. plus new build total iexcludlnqconverslons)396 plus 54forJGSDF hcence -bulldlng bytultAH-IT: IatestSeaCobra 2.05C~shp11529 -kWt7400 -W-402tw1nenglne. 'otal57sofar.w~rhproduction nowresumlngat22 peryear1984 -86Mode1204: baslc commerc'al modelcowspondlng to bH-1 B, :otal not publlslled 3utlricludes over840 bullt by overseas hcermeesModel 205: baslc commemal co8Jnterpar[ofUH-1H, total notoubllshed b ~ t ~ n c l u d ~ n g ~ r ~ l l i r a ~models IUH-1D and Hi exceeds 10,000Model 212: basic cornmerclal counterpat ofUN -1N.totalnotpubl~shedbutwcIlover100sold by Ayusta and In prodilctlon bythatcompany and BellModel412: new product hnewtth four-blddernaln rotor, otherwise based on Tw~nTwo -Twelve; rotallm1d -1983)about120plus 50+ byAgusta lnclddlng latter's milltl -role AB 41 2GrlfuneMode1214: famllyof much more powcrfulandlarger machines. first productlon model belngModel 214A1287 for lran)and AB 214B byAgusta, current Bellverslon~sModel21451producedatthrce permorth since mld 1OE2