Im­prov­ing the breed

The UH-1B to UH-1P

Aviation Classics - - CONTENTS -

The in­tro­duc­tion of the UH-1A into ser vice had re­vealed re­stric­tions in the per­for­mance of the air­craft par­tic­u­larly in hot and high en­vi­ron­ments. In July 1959, the US Army is­sued a con­tract to pro­duce four pro­to­types of a new ver­sion of the he­li­copter, one which was to solve th­ese is­sues and spawn an in­cred­i­ble se­ries of vari­ants.

Even though the first pro­duc­tion vari­ant of the Bell UH-1, the UH1A was con­sid­ered an eval­u­a­tion and tri­als ver­sion of the type by the US Army, it was al­ready prov­ing its re­li­a­bil­ity and adapt­abil­ity in the mede­vac and armed he­li­copter es­cort roles on ac­tive ser­vice in Viet­nam. Prior to th­ese first de­ploy­ments, the US Army had recog­nised the need for greater power and per­for­mance from the he­li­copter, par­tic­u­larly dur­ing an ex­er­cise held in Panama and earth­quake re­lief mission in Chile, where the heat and altitude re­duced the use­ful pay­load of the UH-1 and limited its mission ef­fec­tive­ness. Bell was al­ready con­sid­er­ing a num­ber of im­prove­ments to the ro­tor and air­frame and Ly­coming had de­vel­oped a more pow­er­ful ver­sion of the T53. All of th­ese were dis­cussed with the army, re­sult­ing in a con­tract in July 1959 for four pro­to­types des­ig­nated YUH-1B, the first of th­ese fly­ing on April 27, 1960.

BRAVO BLADES

The new vari­ant of the en­gine, the T53-L-5, pro­duced 960hp, an in­crease in power that was ab­sorbed by a re­designed main ro­tor. The blades were in­creased in chord from the orig­i­nal 14in (35.56 cm) to 21in (53.34 cm) wide but re­tained the orig­i­nal span of 44ft (13.41m). The blades were now made with an ex­truded alu­minium D sec­tion lead­ing edge spar cov­ered in a protective stain­less steel anti-ero­sion strip. Be­hind the spar the body of

the blade was built with a light­weight hon­ey­comb core cov­ered in a glass fi­bre skin, mak­ing the new blades both stronger and lighter than those of the ear­lier Hueys. The most ob­vi­ous change was in the ro­tor mast, which was in­creased in height by 13in (33.02cm) giv­ing the main ro­tor greater ground clear­ance and im­prov­ing its aero­dy­nam­ics. The cabin was en­larged again and was now able to ac­com­mo­date three stretch­ers, two am­bu­la­tory ca­su­al­ties and a med­i­cal at­ten­dant in the mede­vac role. As a trans­port, two air­crew and seven troops and their equip­ment could be car­ried or the can­vas seats could be quickly and eas­ily re­moved and up to 3000lb of cargo loaded in­ter­nally. The max­i­mum loaded weight of the Huey had in­creased from 5800lb (2631kg) in the UH-1A to 8500lb (3850kg) in the B model, nearly a third in­crease in load lift­ing ca­pa­bil­ity. The US Army be­gan testing the first UH-1BS in Novem­ber 1960 with the first pro­duc­tion air­craft en­ter­ing ser­vice in March the fol­low­ing year. Two sub-types were des­ig­nated, a sin­gle NUH-1B which was used for testing a va­ri­ety of new sys­tems and a pair of GUH-1BS which were ground in­struc­tional air­frames. With the de­ploy­ment of UH-1AS to Viet­nam with the Util­ity Tac­ti­cal Trans­port He­li­copter Com­pany (UTTHCO) in Oc­to­ber 1962, the lim­i­ta­tions of the early armed Huey be­came ap­par­ent as they car­ried out their role as armed es­corts to larger trans­port he­li­copters. Th­ese first field mod­i­fi­ca­tions al­lowed both rock­ets and ma­chine guns to be car­ried, but fixed in the di­rec­tion of the line of flight, lim­it­ing their use­ful­ness. The in­creased lift­ing ca­pac­ity of the UH-1B al­lowed a greater range of weapons to be car­ried; to com­ple­ment this a va­ri­ety of mounts were de­vel­oped to im­prove the UH-1S of­fen­sive and de­fen­sive ca­pa­bil­i­ties. A com­plete de­scrip­tion of the weapons sys­tems and mounts de­vel­oped for the Huey would fill this is­sue on its own, so the ma­jor sys­tems fit­ted to the early ‘short body’ mod­els are listed in the ac­com­pa­ny­ing ta­ble.

XM156/M156 – The first ‘uni­ver­sal’ mount de­vel­oped for a va­ri­ety of weapons, usu­ally fit­ted on the fuse­lage sides at the rear of the cabin un­der the cen­tre of grav­ity. Dur­ing tri­als th­ese were also fit­ted at the for­ward end of the cabin, a prac­tice used rarely on op­er­a­tional air­craft due to cen­tre of grav­ity lim­i­ta­tions. A sim­i­lar mount­ing, known as a Kel­lett py­lon had been de­vel­oped by UTTHCO dur­ing early 1963 and al­lowed a sim­i­lar va­ri­ety of weapons to be car­ried, in­clud­ing bombs and na­palm tanks, but th­ese were quickly re­placed by the M156 on ser­vice air­craft. Both types could be fit­ted with two py­lons per mount for weapons, or carry a sin­gle py­lon with ma­chine guns mounted on the ends. Fit­ted to ex­am­ples of all of the early mod­els of the UH-1.

XM6/M6 – The fa­mous ‘Quad’ or ‘Flex’ gun sys­tem was the first to use the new M156 mounts with four M60C 7.62mm ma­chine guns fed by elec­tric drive mo­tors from ammunition boxes in the cabin. Tri­als took place in the for­ward and rear mounted po­si­tion, the lat­ter be­com­ing stan­dard on op­er­a­tional air­craft.the M6, as it was des­ig­nated in May 1963, could also be fit­ted with four twin tube MA-2/A 2.75in rocket launch­ers on each mount.this was a tremen­dous in­crease in fire­power and ca­pa­bil­ity for the UH-1, not least be­cause the co-pi­lot could steer the guns by de­press­ing a ‘dead man switch’ on the pan­to­graphic sight mounted in the roof.this sight al­lowed the guns to be el­e­vated up to 15º above or de­pressed to 60º be­low the he­li­copters line of flight, or moved up to 12º in­board or 70º out­board, the guns hav­ing a safety cut off to pre­vent fir­ing into the fuse­lage. If the dead­man switch were re­leased, the hy­drauli­cally driven mounts au­to­mat­i­cally re­turned to the fixed for­ward po­si­tion, the pi­lot be­ing able to fire them in this mode us­ing the trig­ger on his cyclic.the four guns fired 2200 rounds a minute, the abil­ity to off­set them from the line of flight mak­ing them far more ef­fec­tive than the ear­lier mounts. Sim­ple and re­li­able, the M6 sys­tem of­ten had rocket launch­ers added in the field, the ad­di­tional fire­power be­ing fur­ther sup­ple­mented by door gun­ners with bungee slung M60 ma­chine guns.a devel­op­ment, the XM9, saw the four M60 ma­chine guns re­moved and two M75 40mm grenade launch­ers fit­ted in their place, but this was not widely adopted.the M6 was fit­ted to the UH-1B and C mod­els. XM16/M16 – A devel­op­ment of the M6, this added two M157 or M158 rocket pods to the M156 uni­ver­sal mount along with the four ma­chine guns. Both pods con­tained seven tubes for 2.75in rock­ets and were aimed via an M60 re­flex sight mounted in the cock­pit. Like the M6, this sys­tem was fit­ted to both UH-1B and Cs.

XM17/M17 – The Kel­lett two py­lon mount was used to fit four M159 rocket pods car­ry­ing 19 2.75in rock­ets each, a sys­tem fit­ted to a num­ber of UTTHCO UH-1BS and Cs.there is some ev­i­dence to sug­gest a ver­sion based on the M156 mount was also tested, but the weight of the M17 sys­tem limited its use­ful­ness and it was not widely adopted.

XM21/M21 – An­other devel­op­ment of the M16 sys­tem in which the four M60 ma­chine guns were re­placed by a pair of M134 six bar­relled ma­chine guns known as Mini­guns.the high speed rate of fire was a dev­as­tat­ing 4800 rounds per minute with both guns fir­ing to­gether. Ei­ther the orig­i­nal seven tube or a 19 tube rocket launcher could also be car­ried on the M156 mount.

XM22/M22 – Ex­per­i­ments to fit guided mis­siles to the UH-1 be­gan with the AGM-22A, a li­cence built ver­sion of the Nord S-11 wire guided anti-tank mis­sile aimed via an XM-70 sight.the M22 sys­tem was de­vel­oped from this, six mis­siles be­ing car­ried, three on each side of a UH-1B or C on an ex­tended M156 mount.the M22 sys­tem had a num­ber of im­prove­ments over the early tri­als, in­clud­ing the up­graded AGM-22B mis­sile and the XM58 sta­bilised sight.the first 12 UH-1BS with the M22 sys­tem were de­ployed to Viet­nam in Septem­ber 1965, but saw limited use due to the lack of suit­able tar­gets. One other sys­tem was de­vel­oped to use the AGM-22, built by War­rant Of­fi­cer Robert Maxwell in theatre.the Maxwell sys­tem as it be­came known adapted the M3 weapons sys­tem fit­ted to his unit’s he­li­copters by re­mov­ing one or two banks of six rock­ets from the 24 tube packs on ei­ther side of the UH-1. A cus­tom built short py­lon was then added to the out­side of the M3 packs with a launch rail for a sin­gle AGM-22B.

XM26/M26 – The sec­ond gen­er­a­tion of anti-tank mis­siles were also car­ried by the UH-1 in the form of a triple tube launcher pod for the Hughes BGM-71 TOW de­vel­oped in 1963.Th­ese pods were sup­ported by a spe­cialised raised py­lon, the sys­tem in­clud­ing the sight and sen­sor tur­ret mounted in the copi­lot’s nose glaz­ing. Two UH-1BS, 62-12553 and 62-12554, were mod­i­fied and fir­ing tri­als were con­ducted in Ger­many in 1964.The devel­op­ment of the AH-56 attack he­li­copter can­celled the UH-1 TOW pro­gramme and th­ese air­craft were stored.the Easter Of­fen­sive and the in­creased use of ar­mour by the North Viet­namese Army in 1972 meant the two TOW Hueys were de­ployed to Pleiku with the 1st Air Bat­tal­ion. Here they were a de­ci­sive fac­tor in the Battle of Kon­tum in late May, strik­ing 47 tar­gets which in­cluded 24 tanks.

XM29 – The bungee mounted door guns on the UH-1BS and Cs had a num­ber of short­com­ings, so the XM29 pin­tle mount was de­vel­oped to sup­port an M60D 7.62mm ma­chine gun. While more ef­fec­tive than the bungee cords, the mount meant that no other ar­ma­ment could be car­ried so limited its use. Due to this, a frame mount that could swing out from the rear of the cabin was de­vel­oped, known as the Sagami mount.this could take a sin­gle or pair of M60s, an M2HB ma­chine gun or an M134 Mini­gun and was fit­ted to UH-1BS, Cs, Fs, Ps and Ms, in­clud­ing those of the US Navy.

XM50/M50 – A num­ber of UH-1BS, Cs and Ms were fit­ted with both the M5 and M16 or M21 ar­ma­ment sys­tems, des­ig­nated M50 in com­bi­na­tion.

XM52/M52 – An oil tank and pump were mounted in the rear cabin un­der the seats which sprayed oil into a ring of noz­zles in the en­gine ex­haust.this pro­duced a thick white smoke for up to three min­utes to cover as­sault land­ings and was best de­liv­ered at less than 90kts (166kph) and 50ft (15.2m) in altitude.

US AIR FORCE

XM93/XM93E1/M93 – Two M134 Mini­guns were fit­ted on door mounts in USAF UH-1FS and Ps.the E1 ver­sion of the sys­tem in­cluded an M60 re­flex sight for the pi­lot who could fire the guns re­motely when locked for­wards. A sep­a­rate mount and py­lon was of­ten fit­ted along with the door guns to carry a pair of seven tube rocket launch­ers of vary­ing types.

XM94/M94 – As per the XM93, but one or both of the M134 Mini­guns was re­placed by an M129 40mm grenade launcher. This sys­tem was also fit­ted to USAF UH-1FS and Ps.

US MARINE CORPS

TK-2 – The US Marine Corps de­vel­oped the Tem­po­rary Kit 2 weapons sys­tem for its UH-1E he­li­copters, designing and fab­ri­cat­ing its own mounts to sup­port two M60C 7.62mm ma­chine guns on each side of the rear cabin. Out­board of th­ese a sin­gle py­lon was fit­ted at the end of the mount and could take a va­ri­ety of weapons, most fre­quently seven tube rocket launch­ers, but could also carry Gen­eral Elec­tric SM-14 pods hous­ing Brown­ing .50 cal ma­chine guns.the first of th­ese kits was de­liv­ered to VMO-6 at Camp Pendle­ton in Jan­uary 1965.

TAT-101 – The Emer­son Tac­ti­cal Ar­ma­ment Tur­ret 101 was only fit­ted to US Marine Corps UH-1ES and con­sisted of two M60 ma­chine guns mounted un­der the cen­tre of the nose with 1000 rounds of ammunition. Used from April 1967 un­til the end of 1972, the tur­ret could ro­tate through 220º of arc, el­e­vate 15º and de­press 45º, giv­ing the weapon a sim­i­lar abil­ity to the US Army’s M6 sys­tem. Main­te­nance and ammunition feed dif­fi­cul­ties led to the tur­ret be­ing with­drawn at the end of the Viet­nam War.

Be­tween March 1961 and early 1965, 1030 UH-1BS were to be built, form­ing the back­bone of the US Army he­li­copter forces in Viet­nam and achiev­ing the Huey’s first over­seas sales, to Australia and Nor­way. By the end of 1964 there were 300 UH-1S in the South East Asia theatre, hav­ing re­placed such types as the Pi­asecki H-21 that they had pre­vi­ously es­corted. As a re­sult the role of the UH-1 in Viet­nam be­came that of the pri­mary trans­port for troops, equip­ment and sup­plies along­side its es­cort and gun­ship mis­sions. To bet­ter ful­fil th­ese roles, as pro­duc­tion con­tin­ued the en­gine was changed to the 1100hp Ly­coming T53-L-9 or 9A and later still the -11 ver­sion of the tur­bine, the ex­tra 140hp th­ese of­fered in­creas­ing the pay­load ca­pa­bil­i­ties of the Huey still fur­ther. As the air­craft de­vel­oped, so did the tac­tics gov­ern­ing their use. The UTTHCO took a page out of the US Marine Corps book in April 1963 with the in­tro­duc­tion of the ‘Ea­gle Flights’, a tech­nique the Marine he­li­copter units had be­gun us­ing the pre­vi­ous year. The fluid na­ture of the guer­rilla war against the Viet Cong meant the re­ac­tion time of the forces com­bat­ing them had to be re­duced to a min­i­mum, or the fleet­ing en­emy forces could dis­ap­pear as quickly as they emerged from the coun­try­side and were dis­cov­ered by re­con­nais­sance forces. To achieve this speed of re­sponse, self con­tained flights of he­li­copters were or­gan­ised, con­sist­ing of a com­mand Huey, be­tween six and eight trans­ports or ‘Slicks’ as they were known, five or six gun­ships, re­ferred to as ‘Frogs’, ‘Guns’ or ‘Co­bras’ depend­ing on the unit and the weaponry car­ried, and fi­nally a sin­gle Mede­vac or ‘Dustoff’ Huey was in­cluded on many mis­sions. Th­ese Ea­gle Flights were es­sen­tially troops and he­li­copters ar­ranged in a quick re­ac­tion force, able to re­spond swiftly to re­con­nais­sance and other in­tel­li­gence data re­gard­ing en­emy move­ments. Once the Ea­gle Flight had en­gaged the en­emy force, then a de­ci­sion could be made about the level of re­in­force­ment re­quired, an­other flight could be despatched, or a larger re­sponse or­gan­ised, depend­ing on the size of the en­emy force en­coun­tered. As the US he­li­copter forces in Viet­nam were built up, the com­pa­nies of the newly ar­rived Avi­a­tion Bat­tal­ions each formed their

own flight, a re­or­gan­i­sa­tion that gath­ered pace as the UH-1 re­placed the CH-21 com­pletely. One prob­lem be­gan to emerge from th­ese ‘Huey only’ es­corted troop trans­port and as­sault mis­sions. The Slicks were some 20 knots faster than the armed Hueys, hence their nick­name, which meant they had to re­duce their cruis­ing speed to keep the for­ma­tion to­gether. It also meant that if the for­ma­tion was bro­ken up for any rea­son, the Hogs of­ten had a dif­fi­cult time in re­gain­ing their es­cort­ing po­si­tion. This prob­lem was al­ready be­ing ad­dressed by the US Army, Bell and sev­eral other he­li­copter man­u­fac­tur­ers.

OTHER DE­VEL­OP­MENTS

In a re­lated sideshoot to th­ese de­vel­op­ments of the Huey, its suc­cess in the armed roles had high­lighted the need for a faster and more ma­noeu­vrable he­li­copter to per­form attack and fire sup­port mis­sions, although this had been recog­nised by Bell very early in the devel­op­ment of the type. The com­pany had pro­posed a two seat attack ver­sion based on the Huey pow­er­plant, ro­tor and tail boom as early as 1958 with the D-245 War­rior, fol­lowed by a re­fined de­sign known as the D-255 Iro­quois War­rior in 1962. In­ter­est from the US Army led to Bell fund­ing a con­cept demon­stra­tor, the Model 207 Sioux Scout, a much mod­i­fied OH-13S with a tan­dem two seat cock­pit, chin tur­ret and stub wings for weapons car­riage. This flew on June 27, 1963, and was sent for eval­u­a­tion by the 2nd Air As­sault Di­vi­sion at Fort Ben­ning in Ge­or­gia. The pi­lots who flew the air­craft were im­pressed, but called for more power and a larger weapons ca­pa­bil­ity. The Army launched its Ad­vanced Aerial Fire Sup­port Sys­tem (AAFSS) pro­gramme for a ded­i­cated attack he­li­copter in 1964 which was won by the Lock­heed AH-56 Cheyenne, but the devel­op­ment prob­lems with this he­li­copter were to cause its can­cel­la­tion in 1972. The com­plex­ity of the AH-56 and the ap­par­ent de­lays al­most from the out­set of the project prompted Bell to fur­ther de­velop its D262 AAFSS en­try in March 1965, the in­ten­tion be­ing to of­fer an in­terim attack he­li­copter to the US Army. Known as the Model 209, the pro­to­type of this two-seat attack he­li­copter first flew on Septem­ber 7 of that year, its speed of devel­op­ment be­ing at­trib­ut­able to its ex­ten­sive com­mon­al­ity with the UH-1 air­frame and sys­tems. A highly suc­cess­ful eval­u­a­tion by the US Army that be­gan in De­cem­ber, com­bined with the wors­en­ing sit­u­a­tion in Viet­nam, led to an or­der be­ing placed for 110 pro­duc­tion air­craft be­ing placed in April 1966. Th­ese were des­ig­nated the AH-1G and named Hu­ey­co­bra, most of­ten short­ened to just Co­bra, the first of th­ese fast gun­ships be­ing de­ployed to Viet­nam in 1967. The full story of this re­mark­able air­craft will be the sub­ject of a fu­ture is­sue of Avi­a­tion Clas­sics. As the attack con­cept was pro­gress­ing, Bell be­gan in­ves­ti­gat­ing the civil ap­pli­ca­tions of the Huey at the same time. The per­for­mance and eco­nom­i­cal op­er­at­ing costs of the tur­bine pow­ered he­li­copter made good fi­nan­cial sense a va­ri­ety of civil roles that had been pre­vi­ously limited by the ca­pa­bil­i­ties of the ear­lier pis­ton pow­ered air­craft. As a con­se­quence, Bell found a ready mar­ket for a civil vari­ant, the first Bell 204B, based on the UH-1B, be­ing de­liv­ered in 1961. The civil Huey vari­ants, roles and cus­tomers will be cov­ered later in this is­sue.

CHAR­LIE CHANGES

While the UH-1B was an marked im­prove­ment in per­for­mance over the A model, par­tic­u­larly in the later batches with the 1100hp ver­sions of the T53 tur­bine, Bell con­sid­ered that there was still a great deal more that could be done aero­dy­nam­i­cally to im­prove the Huey still fur­ther in its rapidly de­vel­op­ing roles. While the new AH-1 gun­ship was in devel­op­ment, a faster and more ma­noeu­vrable Huey to fill this role in the in­terim was ob­vi­ously a de­sir­able goal, but there were other is­sues that needed ad­dress­ing too. One of the prob­lems en­coun­tered by Huey pi­lots in Viet­nam had been the phe­nom­ena of ‘re­treat­ing blade stall’, where the ro­tor blade mov­ing in the op­po­site di­rec­tion to the line of flight would ex­pe­ri­ence an aero­dy­namic flut­ter or stall as it was mov­ing in a much slower air­flow rel­a­tive to the di­rec­tion the blade was turn­ing. This was par­tic­u­larly found in high speed flight, es­pe­cially in div­ing at­tacks where the he­li­copter ac­cel­er­ated rapidly, or in tight turns or other ma­noeu­vres that in­creased the load­ing on the air­craft. The vi­bra­tion and other un­de­sir­able ef­fects this had on the Huey caused strict lim­i­ta­tions to be placed on the ‘ve­loc­ity never ex­ceed’ (VNE) or max­i­mum per­mis­si­ble speed the early Hueys were al­lowed to fly at, as well as re­strict­ing their ma­noeu­vra­bil­ity. Bell had a so­lu­tion al­ready in hand for this prob­lem in the shape of its new Model 540 ro­tor sys­tem which had be­gun devel­op­ment in 1960. The new ro­tor fea­tured a unique pitch change bear­ing called a ‘Door Hinge’, all of the new hub bear­ings be­ing Te­flon coated which meant they did not re­quire lu­bri­ca­tion. The ma­jor dif­fer­ence was in the blades them­selves, which were in­creased in chord from 21 to 27in (53.3 to 68.5cm) and had a larger 45lb (20.4kg) bal­ance weight in the ro­tor tips. It was de­vel­oped by Bell at its own ex­pense and fit­ted to a civil Model 204B for testing by the US Army. In a var­ied flight pro­gramme the new ro­tor proved to have much re­duced vi­bra­tion char­ac­ter­is­tics at all air­speeds and at no time was re­treat­ing blade stall ap­proached dur­ing any of the ma­noeu­vres. The air­craft was flown to 75º and 45º of an­gle of bank in tight turns and abrupt pull ups were made at max­i­mum gross weight, all with pos­i­tive con­trol and no ten­dency to ‘mush out’ of a ma­noeu­vre.

Throt­tle chops and au­toro­ta­tions were also flown, the 70% in­crease in ro­tor in­er­tia caused by the greater blade mass mak­ing this a far less crit­i­cal ma­noeu­vre over the ear­lier mod­els as more en­ergy was stored in the blades, al­low­ing a straight­for­ward en­gine out re­cov­ery to be made even at max­i­mum gross weight. In short, the 540 ro­tor meant that the max­i­mum speed re­stric­tions on the Huey were no longer ap­pli­ca­ble, the ro­tor noise and vi­bra­tion were much re­duced, the Huey was much more ma­noeu­vrable and very much eas­ier to fly and fi­nally, due to the lu­bri­ca­tion free hub and fewer parts in the new sys­tem, eas­ier to main­tain. The im­proved aero­dy­nam­ics of the new ro­tor was com­ple­mented by im­prove­ments to the air­frame, partly to as­sist in ab­sorb­ing the greater power and partly to im­prove the ma­noeu­vra­bil­ity still fur­ther. A new tail­boom was de­signed, 2ft 11.5in (0.9m) longer than the orig­i­nal in­clud­ing a wider chord fin which was cam­bered 7º to re­duce the loads on the tail ro­tor dur­ing ma­noeu­vres. Added to this, new larger el­e­va­tors were fit­ted to im­prove pitch sta­bil­ity and a new dual hy­draulic con­trol sys­tem pro­vided re­dun­dancy in the event of battle dam­age. Also spe­cific to op­er­a­tions in Viet­nam was the re­designed en­gine in­let, of­ten known as a bell mouth, which could be fit­ted with an im­proved air fil­ter sys­tem to counter the ex­tremely dusty con­di­tions in theatre. The 1100 hp T53-L-9 was fit­ted, and as pro­duc­tion con­tin­ued the -11 model of the same power was sub­sti­tuted. The in­ter­nal fuel ca­pac­ity was in­creased to 242 US Gal­lons (916 litres) and the gross weight was in­creased to 9500lb (4309kg), giv­ing the new model a load ca­pa­bil­ity of 4673lb (2120kg). Fi­nally, the pi­tot static head and an­tenna that were mounted on the nose had proved vul­ner­a­ble to dam­age, so were re­lo­cated , the pi­tot head end­ing up on top of the cock­pit. In this guise the new ver­sion was des­ig­nated UH-1C, pro­duc­tion be­gin­ning in June 1965 with the first de­liv­er­ies to the US Army in Septem­ber. A to­tal of 755 C mod­els were built, its ar­rival in Viet­nam and its im­proved weapons pay­load ca­pa­bil­ity and per­for­mance meant the gun­ship es­corts could main­tain their po­si­tion in for­ma­tion with the Slicks, and their in­creased ma­noeu­vra­bil­ity made them far more ef­fec­tive in bring­ing their weapons to bear on the fleet­ing tar­gets the op­pos­ing forces pre­sented.

CAV­ALRY (AIR­MO­BILE)

With the new ca­pa­bil­i­ties be­stowed by the UH-1B and C came the need for a new or­gan­i­sa­tion to make the max­i­mum use of the he­li­copters. The devel­op­ment of the Ea­gle Flight quick re­ac­tion forces has al­ready been dis­cussed, but other units had been trans­ferred to Viet­nam dur­ing 1965 as the US moved out of its ad­vi­sory role and be­gan com­mit­ting ground forces to the fight­ing. Most sig­nif­i­cant of th­ese was the 1st Cav­alry Di­vi­sion (Air­mo­bile) which boasted a force of 428 he­li­copters on its own, mostly UH-1S. The unit had been formed by re­des­ig­nat­ing the 11th Air As­sault Di­vi­sion (Test) on July 1, 1965, and send­ing it di­rectly to Viet­nam, the first of the Di­vi­sion’s 15,787 men ar­riv­ing at An Khe in late Au­gust. The lessons learned in the UTTHCO ex­per­i­ments and early op­er­a­tional ex­pe­ri­ence of the Avi­a­tion Bat­tal­ions and He­li­copter Trans­port Com­pa­nies in sup­port­ing ARVN forces prior to mid-1965 had been put to good use in the devel­op­ment of the first US Army unit specif­i­cally trained and equipped for air­mo­bile war­fare. The first ma­jor ac­tion for the 1st Cav­alry Di­vi­sion (Air­mo­bile) was in the Ia Drang Val­ley dur­ing the Pleiku Cam­paign that Novem­ber, coun­ter­ing a North Viet­namese Army (NVA) of­fen­sive in the Cen­tral High­lands. Be­tween Novem­ber 14 and 17, air as­saults into Land­ing Zone (LZ) X-ray in the val­ley brought the 1st Cav­alry Di­vi­sion troop­ers into con­tact with the 32nd and 33rd Reg­i­ments of the NVA. The fight­ing over the next three days and nights was un­be­liev­ably bloody and with­out pause, and has be­come the sub­ject of a fa­mous book, We Were Sol­diers Once… And Young by the com­man­der of the 1st Bat­tal­ion of the 7th Cav­alry Reg­i­ment, the first unit into LZ X-ray, Lieu­tenant Colonel Hal Moore, and one of the great­est jour­nal­ists of the pe­riod, Joseph L Gal­loway. Gal­loway was in LZ X-ray for the en­tire battle and de­spite be­ing a civil­ian, was awarded the Bronze Star for re­peat­edly

res­cu­ing wounded sol­diers dur­ing the battle. It is one of the most vivid ac­counts of mod­ern war­fare ever com­mit­ted to pa­per and highly rec­om­mended for a full un­der­stand­ing of Air­mo­bile op­er­a­tions. This first ma­jor battle was to set the stamp on fu­ture US he­li­copter op­er­a­tions in Viet­nam, as well as the use of ar­tillery and air power to sup­port them. In­ter­est­ingly, it also de­vel­oped the NVA’S re­sponse to such op­er­a­tions, which was to get in so close to the US troops that the de­fen­sive use of sup­port­ing fire­power was im­pos­si­ble. The Di­vi­sion’s UH-1S were used in ev­ery pos­si­ble role dur­ing this battle, in­clud­ing the new UH-1D which will be cov­ered in the ‘long bod­ies’ ar­ti­cle in this is­sue. Men­tion must be made of two pi­lots in par­tic­u­lar, Cap­tain Ed Free­man and Ma­jor Bruce Cran­dall, both of A Com­pany of the 229th He­li­copter As­sault Bat­tal­ion, the unit that had lifted Moore’s troop­ers into LZ X-ray. On Novem­ber 14, 1965, as the fifth load of troops was be­ing taken into LZ X-ray, the en­emy fire was so heavy that the sec­ond flight of eight UH-1S was told to abort their mission. Cran­dall im­me­di­ately recog­nised that sup­ply and mede­vac mis­sions for the troops al­ready on the ground would be­come crit­i­cal, so he and Free­man vol­un­teered to main­tain sup­port­ing flights into X-ray with wa­ter, food and ammunition, as well as bring­ing wounded sol­diers out. Free­man flew 14 mis­sions that day, Cran­dall 22, suc­cess­fully evac­u­at­ing some 75 wounded troop­ers and keep­ing vi­tal sup­plies reach­ing those en­gaged in the fight­ing. Other units, not un­rea­son­ably, had re­fused to land in the in­tensely ‘hot’ LZ, but Cran­dall and Free­man, in what can only be de­scribed as a dis­play of sheer old fash­ioned guts, kept go­ing back and forth. Their ef­fect on the morale of the troop­ers so des­per­ately en­gaged with the NVA is in­cal­cu­la­ble, as the sol­diers knew sup­plies would be main­tained and the wounded would be taken care of. Quite rightly, the sus­tained and re­peated gal­lantry of both pi­lots was later recog­nised with the award of the Con­gres­sional Medal of Hon­our.

BRIGADE STRENGTH

The in­creas­ing num­ber of he­li­copter units in Viet­nam, some in­de­pen­dent such as the UTTHCO, oth­ers a part of In­fantry or other US Army Di­vi­sions, gave rise to an un­usual prob­lem. In this, the in­fancy of air­mo­bile he­li­copter war­fare, train­ing, pro­ce­dures and tac­tics were a mat­ter of in­di­vid­ual unit pol­icy and op­er­a­tional re­quire­ments, rather than a cen­tral doc­trine. As op­er­a­tions be­came larger and more com­plex, th­ese dif­fer­ences in prac­tices be­came crit­i­cal as units found it dif­fi­cult to work to­gether. Stan­dard­i­s­a­tion be­came vi­tal, so on May 23, 1966, the 1st Avi­a­tion Brigade was formed as the com­mand and train­ing cen­tre for all the in­de­pen­dent he­li­copter units in theatre. Much to the US Army’s credit and clear think­ing, de­spite this be­ing an en­tirely new form of war­fare, the brigade was re­spon­si­ble for stan­dard pro­ce­dures in train­ing, sup­ply, op­er­a­tional meth­ods and main­te­nance, but com­bat com­mand of the he­li­copters re­mained with the unit com­man­der on the ground, achiev­ing max­i­mum in­ter­op­er­abil­ity, but cost­ing none of the flex­i­bil­ity and speed of re­sponse of the orig­i­nal ar­range­ments.

Es­sen­tially, as­sault trans­port he­li­copters were at­tached to in­fantry units, to which re­con­nais­sance, gun­ship, cargo, mede­vac and other as­sets were al­lo­cated as the need arose. By 1968, the Brigade in­cluded 95 units op­er­at­ing 4230 air­craft across the en­tire coun­try, most of which were UH-1S.

THE HUEY GOES TO SEA

The suc­cess of the UH-1 with the US Army and the he­li­copter’s ob­vi­ous high per­for­mance at­tracted the at­ten­tion of the other US ser­vices. First was the US Marine Corps in 1962, which or­dered a small num­ber of UH1Bs to eval­u­ate the type as part of its As­sault Sup­port He­li­copter (ASH) com­pe­ti­tion. The win­ner was to re­place two dis­sim­i­lar air­craft in the Marine Corps in­ven­tory, the Cessna O-1B and C Bird­dog light ob­ser­va­tion air­craft and Ka­man OH-43D Huskie, an un­usual twin in­ter­mesh­ing ro­tor ob­ser­va­tion and util­ity he­li­copter. On March 2, 1962, the Marine Corps se­lected the UH-1 with cer­tain changes to its equip­ment and con­struc­tion. All of the mag­ne­sium com­po­nents were re­moved from the air­frame and re­placed by alu­minium, due to the na­ture of the Marine op­er­a­tional en­vi­ron­ment, salt wa­ter hav­ing a par­tic­u­larly dele­te­ri­ous ef­fect on mag­ne­sium. As the new air­craft would be op­er­at­ing from the con­fines of ships’ decks, a ro­tor brake was added to slow and park the blades quickly as a safety pre­cau­tion. Since one of the roles of the ear­lier Huskies had been com­bat search and res­cue (CSAR) mis­sions, a per­son­nel hoist was added to the cabin roof and lastly, some of the avion­ics and ra­dios were changed for com­pat­i­bil­ity with ex­ist­ing Marine Corps sys­tems. Based on the UH-1B air­frame, the first of the new UH-1ES, Buno 151266, flew on Oc­to­ber 7, 1963, con­duct­ing car­rier tri­als aboard the USS Guadal­canal dur­ing De­cem­ber be­fore en­ter­ing ser­vice with VMO1 at MCAS New River, North Carolina, on Fe­bru­ary 21, 1964. Al­to­gether 209 UH-1ES were built, but af­ter the first 34 had been con­structed, the Bell pro­duc­tion line had geared up to build the UH-1C with its larger tail­boom, in­creased fuel ca­pac­ity and Model 540 main ro­tor. The re­main­ing UH-1ES were there­fore built to the C spec­i­fi­ca­tion, and although a quite dif­fer­ent air­craft it re­tained the orig­i­nal des­ig­na­tion. Marine Corps de­ploy­ments to the Viet­nam theatre saw its Hueys used in the troop trans­port, gun­ship and CSAR roles with VMO2 and VMO-6 from May and Au­gust 1965 re­spec­tively, fol­lowed by VMO-3 in De­cem­ber 1967. Be­fore this in Septem­ber 1964, two weapons sys­tems had been de­vel­oped for the UH-1E, the TK-2 and TAT-101, both of which are de­scribed in the ad­join­ing ta­ble. Also dur­ing the con­flict, many UH-1ES were up­graded with the in­tro­duc­tion of the 1400hp ver­sion of the Ly­coming tur­bine en­gine, the T53-L-13, giv­ing them greater pay­load ca­pa­bil­i­ties and im­prov­ing their hot and high per­for­mance con­sid­er­ably. Th­ese he­li­copters were to be a re­li­able and popular ad­di­tion to USMC in­ven­tory, 128 sur­viv­ing the Viet­nam War, many re­main­ing in ser­vice un­til the mid 1980s. One other ver­sion of the UH-1E was des­ig­nated; a pi­lot trainer known as the TH-1E, for which 20 Bunos, 154730 to 154749, were al­lo­cated, but it is un­clear if th­ese were ever built as no con­struc­tor num­bers are avail­able. One UH-1E, 154778, was con­verted into a ground in­struc­tional air­frame des­ig­nated GUH-1E in 1986 and given the USAF se­rial of 84-0474, af­ter which it was used at Chanute Air Force Base in Illi­nois be­fore be­ing trans­ferred to the Do­mini­can Repub­lic Air Force.

USAF AND NAVY HUEYS

The US Air Force in­ter­est in the Huey be­gan with a re­quire­ment for a he­li­copter to sup­port the many In­ter­con­ti­nen­tal Bal­lis­tic Mis­sile bases all across the United States. This would have to be able to carry 4000lb (1815 kg) of cargo or a mis­sile site crew of up to 10 per­son­nel. One fur­ther stip­u­la­tion was the use of the 1250hp Gen­eral Elec­tric T58-GE-3 tur­boshaft to pro­vide a parts and main­te­nance com­mon­al­ity with the Siko­rsky HH-3 Jolly Green Gi­ant fleet then in ser­vice. Bell mod­i­fied the short cabin UH-1B to take the new en­gine and added the longer 48ft (14.63m) span Model 540 ro­tor from the UH-1D. This was to ab­sorb the ad­di­tional power and pro­vide the nec­es­sary per­for­mance to pro­duce an air­craft ini­tially des­ig­nated the XH-48A. The longer ro­tor also meant the longer tail­boom of the D also had to be fit­ted; re­sult­ing in a short but pow­er­ful ver­sion of the Huey, later re­des­ig­nated the UH-1F. In 1963, the up­graded de­sign was se­lected as the com­pe­ti­tion win­ner, the first of the 120 UH1Fs built fly­ing on Fe­bru­ary 20, 1964, be­fore en­ter­ing ser­vice with the 4486th Test Squadron at Eglin Air Force Base on Septem­ber 23 later that year.

An ad­di­tional 26 air­frames were built in 1967 to act as pi­lot and crew hoist train­ers un­der the des­ig­na­tion TH-1F, serv­ing with a num­ber of USAF fly­ing schools. Dur­ing the Viet­nam War a first batch of 20 UH-1FS were mod­i­fied to take the M93 and M94 weapons sys­tems as de­scribed in the sep­a­rate ta­ble. Th­ese were used in the gun­ship role, of­ten along­side the un­armed UH-1F trans­ports and were known as UH-1PS. The first of th­ese gun­ships were sup­plied to the 1st Spe­cial Op­er­a­tions Squadron (SOS) at Hurl­burt Field in Florida for tri­als, the batch sent to Viet­nam be­ing op­er­ated by the 20th SOS, known as ‘The Green Hor­nets’. The UH-1FS were to re­main in ser­vice un­til re­placed by the twin en­gined UH-1NS dur­ing the 1980s. The US Navy be­gan us­ing the UH-1 in 1965 with the for­ma­tion of Task Force 116 in Viet­nam. This force was es­tab­lished to keep the Mekong Delta free of en­emy ves­sels and trans­port and was made up of Pa­trol Boats (PBRS) and SEAL spe­cial forces teams. He­li­copters to sup­port th­ese forces were ini­tially ac­quired from the US Army, which loaned eight UH-1BS from the 197th Avi­a­tion Com­pany to form four two ship flights across the re­gion, the flights be­com­ing known as the Seawolves, the first to begin op­er­a­tions be­ing Det 29 in Oc­to­ber 1966. The flights were of­fi­cially formed into He­li­copter Attack (Light) -3 Squadron (HA(L)-3) in the spring of 1967, three more flights be­ing formed to cover the delta more ef­fec­tively with 33 UH-1BS be­ing on strength by 1969. The navy recog­nised two spe­cific re­quire­ments for the UH-1 dur­ing this pe­riod which re­sulted in two more mod­els be­ing de­vel­oped. The first was on May 16, 1968, with Bell be­ing awarded a con­tract to sup­ply 45 TH-1L crew trainer he­li­copters based on the UH-1E but with the 1400hp T53-L-13 en­gine and im­proved avion­ics. The first were de­liv­ered in Novem­ber 1969 and even­tu­ally 90 of this ver­sion were built, along­side eight of a util­ity trans­port vari­ant known as the UH-1L, or­dered at the same time as the train­ers. Four of the L vari­ant were sent to the HA(L)-3 de­tach­ment at Binh Thuy and took part in Op­er­a­tion Sealords, which stood for Southeast Asia Lake, Ocean, River and Delta Strat­egy, the sys­tem­atic cut­ting of North

Viet­namese sup­ply lines from Cam­bo­dia via the rivers and Mekong Delta be­tween 1968 and 1971. Here they were ar­moured and armed with a sim­i­lar sys­tem to the US Marine’s TK-2 weapons and py­lons, ca­pa­ble of car­ry­ing ma­chine guns, rock­ets and 500lb (230 kg) bombs, both con­ven­tional and fuel-air ex­plo­sive types. Th­ese two mod­els were used as the ba­sis for 27 HH-1KS, an air sea res­cue he­li­copter with ad­di­tional mission equip­ment. The first was de­liv­ered in May 1970, three be­ing sent to serve a CSAR air­craft with HA(L)-3 in Novem­ber that year.

THE LAST SHORT

The ad­vent of the 1400hp ver­sion of the T53 en­gine gave rise to the sev­eral of the up­graded ver­sions of the short bod­ied Huey as al­ready dis­cussed, the last of th­ese be­ing the US Army’s UH-1M. Th­ese were all con­ver­sions from UH-1CS with the larger en­gine to al­low bet­ter per­for­mance when fully loaded with weapons in the gun­ship role. As the T53-L-13 was also fit­ted to the trans­port long body UH-1H Hueys, it made sense from a spares and main­te­nance point of view to have a com­mon­al­ity of en­gines be­tween the types. A num­ber of ad­di­tional sen­sor sys­tems were fit­ted to UH-1MS due to their in­creased lift­ing power, in­clud­ing the Hughes Iro­quois Night Fighter and Night Tracker (IN­FANT) low light TV, im­age in­ten­si­fier and In­fra Red searchlight sys­tem to as­sist in aim­ing the M21 weapons sys­tem with its mini­guns and rocket launch­ers. Five more UH-1MS were fit­ted with the AN/AAQ-5 For­ward Look­ing In­fra Red (FLIR) tur­ret in a sim­i­lar po­si­tion to the ear­lier M5 40mm grenade launcher, again used in con­junc­tion with the M21 weapons sys­tem. At the same time as all th­ese de­vel­op­ments of the short bod­ied de­sign had been go­ing on, the cabin had been stretched to pro­duce high ca­pac­ity trans­port ver­sion of the he­li­copter. Th­ese have al­ready been men­tioned in this nar­ra­tive as the sto­ries of the long and short bod­ied Hueys in­ter­twine. Known as the Bell Model 205 by the com­pany, th­ese vari­ants will be de­scribed in full on page 56 of this is­sue. Words: Tim Call­away

US Army

The clas­sic im­age of the Huey in Viet­nam and the life­line it rep­re­sented to the de­ployed troops in the field. Here, dur­ing Op­er­a­tion Macarthur in De­cem­ber 1967, a UH-1B flies a re­sup­ply mission for B Com­pany, 1st Bat­tal­ion of the 8th In­fantry some 20 miles south­west of Dak To.

US Army

One of the lesser known roles for the UH-1B in Viet­nam was con­duct­ing ‘psy­ops’, psy­cho­log­i­cal war­fare against en­emy forces us­ing pow­er­ful broad­cast speak­ers.

US Army Avi­a­tion Mu­seum

The in­creased power of the UH-1B is ev­i­dent in this pho­to­graph of one re­cov­er­ing an­other while on ex­er­cise in the south­ern US.

Later door gun mounts were de­vel­oped to carry the M60, or as seen here mounted on US Navy UH-1S, the Brown­ing .50 Cal or M134 mini­gun.the Sagami mount was widely adopted as were a num­ber of other pin­tle sys­tems for door gun­ners.

US Army Avi­a­tion Mu­seum

The M6, the fa­mous ‘Quad’ or ‘Flex’ gun sys­tem used the new M156 mounts with four M60C 7.62mm ma­chine guns fed by elec­tric drive mo­tors from ammunition boxes un­der the rear bench seat in the cabin.the guns are shown here in their de­pressed po­si­tion.

US Army Avi­a­tion Mu­seum

A close up of the XM26 sys­tem on a UH-1B show­ing the front end of the mis­sile pod and the nose mounted sen­sor and aim­ing tur­ret.

The M17 sys­tem used the Kel­lett two py­lon mount to fit four M159 rocket pods car­ry­ing 19 2.75in rock­ets each, a sys­tem fit­ted here to a UTTHCO UH-1B, but not widely adopted due to its weight.

US Army Avi­a­tion Mu­seum

The M22 sys­tem fit­ted six AGM-22A wire guided anti-tank mis­siles, a li­cence built ver­sion of the Nord S-11, aimed via an XM-70 sight.

US Army Avi­a­tion Mu­seum

The co-pi­lot’s cock­pit of a UH-1B fit­ted with the XM26 sys­tem show­ing the sen­sor tur­ret binoc­u­lar sight and mis­sile steer­ing con­troller.

US Army Avi­a­tion Mu­seum

The M16 added two M157 or M158 rocket pods to the M6, each con­tain­ing seven tubes for 2.75in rock­ets which were aimed via an M60 re­flex sight mounted in the cock­pit. Here the M60s are shown in the fully raised po­si­tion.

US Army Avi­a­tion Mu­seum

US Navy

US Army Avi­a­tion Mu­seum US Army Avi­a­tion Mu­seum US Army Avi­a­tion Mu­seum

A close up view of the AGM-22A mis­siles of the M22 sys­tem on their mount. War­rant Of­fi­cer Robert Maxwell adapted the M3 weapons sys­tem by re­mov­ing one or two banks of six rock­ets from the 24 tube packs then adding a launch rail for a sin­gle AGM-22B. A rare colour shot of one of the UH-1BS fit­ted with the XM26 sys­tem with two pods of three Hughes BGM-71 TOW anti-tank mis­siles with the nose mounted sen­sor and aim­ing tur­ret.

US Army Avi­a­tion Mu­seum

Two views of the M21 sys­tem with a pair of M134 six bar­relled ma­chine guns known as Mini­guns mounted on the ends of the M156 mounts which could also carry a seven tube or a 19 tube rocket launcher.

USMC

Two US Marine Corps UH-1ES fit­ted with the Tem­po­rary Kit 2 (TK2) weapons sys­tem with two M60C 7.62mm ma­chine guns and seven tube rocket launch­ers. Note both air­craft also have the Emer­son Tac­ti­cal Ar­ma­ment Tur­ret 101 with two M60 ma­chine guns.

When the M16 or M21 ma­chine gun sys­tem on the M156 mounts was fit­ted along with the M5 grenade launcher in the nose tur­ret, the com­bi­na­tion was re­ferred to as the M50 as seen here.

US Army Avi­a­tion Mu­seum

One of the two XM26 equipped UH-1BS seen dur­ing the early tri­als be­fore a pe­riod in stor­age af­ter which the air­craft were cam­ou­flaged and sent to Viet­nam.

USMC

A close up of the Tem­po­rary Kit 2 (TK2) weapons sys­tem with two M60C 7.62mm ma­chine guns and a seven tube rocket launcher on a USMC UH-1E.

US Army Avi­a­tion Mu­seum

The sling hold­ing this M60 is typ­i­cal of the early bungee cord door gun mounts.

US Army A UH-1C fit­ted the M50 sys­tem com­pris­ing the M5 along with the M21 sys­tems. US Army Avi­a­tion Mu­seum

US Army Avi­a­tion Mu­seum

Loaded for bear. A UH-1B fit­ted with the M3 rocket packs con­tain­ing 48 2.75in Mk.40 FFARS and the M5 nose mounted 40mm grenade launcher tur­ret.

Avi­a­tion Mu­seum US Army

A UH-1B fit­ted with the M3 Aerial Rocket Ar­tillery or ARA sys­tem, with the sec­ond 24 rocket pack in the cabin.

US Army

A UH-1B show­ing the ‘bell mouth’ air in­take to the en­gine, nose mounted an­tenna and pi­tot head and the base of the M156 com­mon weapon mounts just aft of the cabin doors.

Bell

The UH-1B was also used to con­duct long range and ferry ex­per­i­ments with ex­ter­nal tanks.

US Army

The in­creased lift­ing power of the UH-1B al­lowed com­bi­na­tions of ar­ma­ment such as t he M50 to be car­ried, here con­sist­ing of the M5 nose mounted 40mm grenade launcher tur­ret and a pair of M156 mounts with the quad M60 flex guns and two seven tube rocket pods.

US Navy

A grainy but in­ter­est­ing shot of the USS Gar­ret County, a Sec­ond World War Land­ing Ship Tank (LST) con­verted for use as a he­li­copter plat­form and pa­trol craft ten­der. Moored in the Mekong Delta, the ship has a UH-1B fur­thest from the cam­era, with ei­ther a UH-1C or M with its broader fin closer to the cam­era.

Bell

The Bell D-255 Iro­quois War­rior mock up pre­sented to the US Army for the Ad­vanced Aerial Fire Sup­port Sys­tem (AAFSS) pro­gramme.

US Army Avi­a­tion Mu­seum

The US Army’s build up and re­or­gan­i­sa­tion of he­li­copter forces in Viet­nam in­cluded the 1st Cav­alry Di­vi­sion (Air­mo­bile) which boasted a force of 428 he­li­copters on its own, ar­riv­ing in theatre in Au­gust 1965. The sheer air power th­ese forces could deploy was an im­pres­sive in­tro­duc­tion of a whole new form of war­fare.

US Army Avi­a­tion Mu­seum

The UH-1C fea­tured a broader chord fin cam­bered 7º to port to help un­load the tail ro­tor at high speeds.

Bell

Bell funded an AAFSS con­cept demon­stra­tor, the Model 207 Sioux Scout, a much mod­i­fied OH-13S with a tan­dem two-seat cock­pit, chin tur­ret and stub wings for weapons car­riage.

Bell

The de­vel­op­ments led to a fur­ther Bell funded project, the Model 209.This is the sec­ond pro­to­type of the Bell AH-1 Co­bra he­li­copter gun­ship, seen with the early re­tractable un­der­car­riage. Its roots in the UH-1 de­sign are un­mis­take­able.

US Army Avi­a­tion Mu­seum

Bruce Cran­dall was to win the Con­gres­sional Medal of Hon­our for his sus­tained brav­ery dur­ing the first ma­jor 1st Cav­alry Di­vi­sion (Air­mo­bile) en­gage­ment, the battle of the Ia Drang Val­ley in Novem­ber 1965. Here he is seen lead­ing a for­ma­tion of UH-1 he­li­copters from Al­pha Com­pany of the 229th Avi­a­tion Reg­i­ment just prior to take­off in Viet­nam later in 1966.

Avi­a­tion Mu­seum US Army

The UH-1C solved many of the aero­dy­namic prob­lems of the ear­lier Hueys through the ad­di­tion of the Model 540 ro­tor with its broader 27in chord blades, sim­pli­fied hub and pitch con­trol mech­a­nism.

US Army Avi­a­tion Mu­seum

This ser­pent is painted on the door of Bruce Cran­dall’s UH-1D he­li­copter, a Huey vari­ant cov­ered in de­tail later in this is­sue. Such images en­abled fel­low pi­lots and ground com­man­ders to iden­tify pi­lots by their dis­tinc­tive call signs and door mark­ings. Cran­dall’s call­sign was An­cient Ser­pent Six.

USMC

The US Marine Corps was the first ser­vice af­ter the US Army to de­velop its own ver­sions of the Huey. Here Marine UH-1ES touch down with their loads at Fire Sup­port Base Cun­ning­ham in 1969.

USMC

US Marine Corps UH-1ES were also fit­ted with a per­son­nel hoist on the cabin roof, seen here in the stowed po­si­tion with hoist arm re­tracted and hook in its re­cess above the cabin door.

US Army Avi­a­tion Mu­seum

Ma­jor Bruce Cran­dall’s UH-1D lifts off af­ter dis­charg­ing in­fantry­men on a search and de­stroy mission.

USMC

A US Marine Corps UH-1E fit­ted with the TK-2 weapons mounts with four M60 ma­chine guns and a 500lb Fuel Air Ex­plo­sive bomb.the door gun­ner also has an M60 ma­chine gun.

Ruth AS

The USAF UH-1FS all fea­tured the 1250hp Gen­eral Elec­tric T58-GE-3 tur­boshaft en­gine with a star­board fac­ing ex­haust.this is a Bell TH-1F pi­lot trainer ver­sion seen in 1975 when serv­ing with the In­stru­ment Flight Cen­tre at Ran­dolph Air Force Base.

USAF

A num­ber of the USAF UH-1FS were con­verted with weapons mounts as the UH-1P, in­clud­ing pin­tle ma­chine gun door mounts as seen here.this is a pre­served ex­am­ple in the Na­tional Mu­seum of the United States Air Force at Wright Pat­ter­son Air Force Base in Ohio.

US Navy

A Bell TH-1L Iro­quois crew trainer of He­li­copter Train­ing Squadron 8 (HT-8) pic­tured in flight over North­west Florida.

USAF

A UH-1P ready for a covert mission, note the flex­i­ble lad­der that could be ex­tended to pick up per­son­nel when the he­li­copter could not land.

US Navy

Be­fore the devel­op­ment of the UH-1L for the US Navy, a num­ber of UH-1BS, Cs and Ms were trans­ferred from the US Army to HA(L)-3 to es­cort PBRS op­er­at­ing in the Mekong Delta, as seen here in 1968.

Con­stance Red­grave

Above: On dis­play at the Na­tional Mu­seum of Naval Avi­a­tion at Pen­sacola Florida is this Bell HH-1K, the US Navy’s search and res­cue ver­sion of the Huey.this air­craft is dis­played in the mark­ings of HA(L)-3, but ac­tu­ally saw ser­vice in Viet­nam with HA(L)-5.

US Army Avi­a­tion Mu­seum

Two views of a UH-1M fit­ted with the M21 weapons sys­tem and the Hughes Iro­quois Night Fighter and Night Tracker (IN­FANT) low light TV, In­fra Red and searchlight sys­tem to as­sist in aim­ing the weapons at night.

USAF

Left: One USAF covert mission, known as Pony Ex­press, sup­ported se­cret mis­sions and radar sites in Laos.this is a UH-1P of the 20th SOS at Duc Lap, South Viet­nam, loaded with lum­ber and ply­wood sheets.

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