UNITED STATES MILITARY AIRCRAFT by Jos Heyman

Army (1956 - 1962) Last update: 1 February 2015

AC = Aircraft/Transport

AC-1 De Havilland Canada DHC-4 Caribou Specifications: span: 95'7", 29.13 m length: 72'7", 22.13 m engines: 2 Pratt & Whitney R-2000-7M2 max. speed: 216 mph, 348 km/h

(Source: US Army)

The Caribou was a transport aircraft for 32 troops which flew for the first time on 30 July 1958 as a company aircraft. The US Army ordered five for evaluation as YAC-1 with serials 57-3079/3083 of which the first flew in March 1959. Following this 56 AC-1 production aircraft were ordered with serials 60-3762/3768, 60-5430/5444, 61-2384/2407 and 61-2591/2600. After this production switched to the AC-1A version of which 55 with serials 62-4144/4196 and 62-12583/12584 were ordered prior to the change in designation. On 18 September 1962 those YAC-1s and AC-1s remaining in service were redesignated as CV-2A, whilst the production of the AC-1A and the AC-1B continued as CV-2B. Refer also to C-7 and V-2

AC-2 De Havilland Canada DHC-5 Buffalo Specifications: span: 99', 30.18 m length: 79', 24.08 m engines: 2 General Electric CT-64 max.speed: 282 mph, 454 km/h

(Source: US Army)

The Buffalo was a medium transport aircraft for which the AC-2 designation was reserved. No aircraft were ordered using this designation and production took place as CV-7A. Refer also to V-7 and C-8

AO = Aircraft/Observation

AO-1 Grumman G-134 Mohawk Specifications: span: 42', 12.80 m length: 41', 12.50 m engines: 2 Lycoming T53-L-3 max.speed: 290 mph, 466 km/h

(Source: Johan Visschedijk, via 1000aircraftphotos.com photo #4741/

The US Army version of the Mohawk, a light observation aircraft, was a development of the OF design for the USMC. Nine aircraft were ordered as YAO-1A, which had serials 57-6463/6467 and 57-6538/6541. The first one flew on 13 April 1959. This was followed by the AO-1A production version of which 43 were ordered with that designation and with serials 59-2603/2620 and 60-3720/3744. The AO-1B version was fitted a side looking radar in a fuselage pod. 65 were ordered with this designation and with serials 59-2621/2637 and 62-5859/5906. The aircraft had an increased span of 48', 14.63m and a length of 43'1", 13.13m and had T53-L-7 engines. The AO-1C version carried infra-red ground surveillance sensors and 81 were ordered with this designation and with serials 60-3745/3761, 61-2675/2728 and 62-5849/5858. On 18 September 1962 those YAO-1As, AO-1As, AO-1Bs and AO-1Cs remaining in service were redesignated as, respectively, YOV-1A, OV-1A, OV-1B and OV-1C. Production of the latter two continued with those designations. The AO-1E designation was reserved for a version fitted with Lycoming T53-L-7 engines which eventually was redesignated as OV-1E but was never built as such. Refer also to V-1 and OF

AO-2 Goodyear GA-466 Inflatoplane Specifications: span: 28', 8.53 m length: 19'2", 5.84 m engines: 1 McCullouch 4318E max.speed: 70 mph, 112 km/h

(Source: US Army)

The Inflatoplane was a light observation aircraft built from Airmat, a material consisting of layers of nylon fabric joined by thousands of dropped threads. When inflated the layers of nylon were forced apart and the threads were stretched taut by the air thereby forming the wing and tail surfaces of the aircraft. The US Army procured a single aircraft for evaluation with the designation YAO-2 and serial 57-6537. The same aircraft has also been referred to as XAO-2. No further development was undertaken as there was no perceived mission for the aircraft. One reference has suggested that this aircraft was originally designated as AZ-1. Refer also to AO-3 and AZ-1

AO-3 Goodyear GA-468 Inflatoplane Specifications: span: 22', 6.71 m length: 19'8", 6.00 m engines: 1 Nelson H63A max.speed: 72 mph, 115 km/h

(Source: US Army)

The 468 Inflatoplane was a single-seat version of the AO-2 design. Five were ordered by the US Army as YAO-3 with serials 57-6532/6536. The designation XAO-3 has also been referred to for these aircraft. The first flight was on 28 May 1957 and testing was also conducted by the US Navy as an escape, evasion, limited reconnaissance and downed pilot rescue vehicle for the Marine Corps. Tests included landings on water. No further development was undertaken as there was no viable mission for the aircraft and it was cancelled in November 1960 before completion of testing. One reference has suggested that this aircraft was originally designated as AZ-1. Refer also to AO-2 and AZ-1

AU = Aircraft/Utility

AU-1 De Havilland Canada DHC-3 Otter Specifications: span: 58', 17.68 m length: 41'10", 12.75 m engines: 1 Pratt & Whitney R-1340-S3H1 max.speed: 150 mph, 241 km/h The designation AU-1 was reserved for a number of aircraft for the US Army which, eventually, were purchased under the U-1 designation. Refer also to U-1 and UC

AZ = Aircraft/Experimental

AZ-1 Mississippi State University Marvellette Specifications: span: 26'2", 7.98 m length: 28'5", 8.66 m engines: 1 Continental C96-12 max.speed: 125 mph, 201 km/h

(Source: Mississipi State University)

The XAZ-1 was a research aircraft to study the aspects of boundary layer control by means of a variable camber wing of a glass fibre construction, which incorporated a perforated surface and suction pumps. The research programme was managed by the Mississippi State University. The single aircraft ordered, carrying serial 62-12147, was built from a Greenwood AC-14 N3091K by Parsons Co. and flew for the first time on 16 November 1962. By March 1964 it had made 16 flights following which the aircraft was scrapped. The research programme continued with the XV-11A Marvel. There is no evidence to suggest that the aircraft received a post-September 1962 designation in the Tri-service designation system and until 1990 the usual reference sources have omitted this designation. One reference has suggested that the AZ-1 was initially used for the AO-2 and AO-3 designs. Refer also to AO-2 and AO-3

HC = Helicopter/Transport

HC-1 Vertol 107/114 Specifications: YHC-1A YHC-1B rdm: 48'4", 14.73 m 59'1", 18.01 m length: 44'4"' 13.51 m 51', 15.54 m engines: 2 General Electric 2 Lycoming T58-GE-6 T55-L-5 max.speed: 165 mph, 263 km/h 186 mph, 299 km/h

(Source: US Army Aviation Museum)

The designation includes two different designs of this transport helicopter: the model 107 as YHC-1A and HC-1A, and the model 114 as YHC-1B and HC-1B. Three YHC-1As were procured in 1958 and the first of these flew on 27 August 1959 although the company owned prototype had earlier flown on 22 April 1958. The serials were 58-5514/5516 whilst 58-5517/5523 were cancelled. Aircraft remaining in service after 18 September 1962 were redesignated as YCH-46A. The HC-1A designation was applied to a production version which was later redesignated as CH-46C. Five examples of the YHC-1B were ordered with serials 59-4982/4986 and the first aircraft flew on 21 September 1961. This was in fact the second aircraft as the first one had been damaged on 28 April 1961 and never flew. They were redesignated as YCH-47A on 18 September 1962. The production version was designated HC-1B and 47 examples were ordered with serials 60-3448/3452, 61-2408/2425 and 62-2114/2137 before the designation changed into CH-47A on 18 September 1962, under which production continued. Refer also to H-46, H-47 and HRB

HO = Helicopter/Observation

HO-1 Sud Aviation SO1221 Djinn Specifications: rdm: 36'1", 11.00 m length: 17'4", 5.28 m engines: 1 Turbomeca Palouste IV max.speed: 80 mph, 129 km/h

(Source: Ray Watkins, via 1000aircraftphotos.com photo #11198)

The Djinn was a light two seat helicopter. The US Army acquired three examples for evaluation with the designation YHO-1 and serials 57-6104/6106. On completion of the trials, in 1958, the aircraft were to be sold to the French Army but the aircraft had crashed before that time and never were sent to France. The designation was also briefly used for the Hiller VZ-1.

HO-2 Hughes Specifications: rdm: 25'. 7.62 m length: 22'4", 6.81 m engines: 1 Lycoming O-360-C2B max.speed: 86 mph, 138 km/h The designation YHO-2 was initially designated to a military version of the De Lackner DH-4 Aerocycle which was later redesignated as HZ-1.

(Source: US Army)

The designation YHO-2 was then applied to the Hughes light observation helicopter based on the model 269A. Five were ordered as XH-42 with the serials 58-1324/1328 and were later redesignated as YHO-2. The first flight took place in October 1956. Eventually the helicopter was adopted as a primary trainer with the designation TH-55A. Refer also to H-42, H-55, HZ-1

HO-3 Brantley B2 Specifications: rdm: 23'9". 7.24 m length: 21'9", 6.63 m engines: 1 Lycoming VO-360-A1A max.speed: 100 mph, 161 km/h

(Source: US Army)

The Brantley B2 first flew on 21 February 1953. Five were ordered by the US Army in 1959 as YHO-3 for evaluation as a light observation helicopter. The serials used were 58-1492/1496.

HO-4 Bell 206 Specifications: rdm: 35'4", 10.77 m length: 32'7", 9.93 m engines: 1 Allison T63-A-5 max.speed: 138 mph, 222 km/h

(Source: David Hatcher, via 1000aircraftphotos.com photo #5502)

Five were ordered by the US Army as YHO-4 for evaluation as a light observation helicopter. They were redesignated as YOH-4A before delivery in 1962. The assigned serial numbers were 62-4202/4206. Originally the assigned serials were 62-4201/4205 but that was changed due to serial 62-4201 having been assigned to a Lockheed VC-140. Refer also to H-4, H-57 and H-58.

HO-5 Fairchild Hiller FH1100 Specifications: rdm: 35'5", 10.80 m length: 39'10", 12.13 m engines: 1 Allison T63-A-5 max.speed: 129 mph, 205 km/h

(Source: Fairchild Hiller)

Five were ordered by the US Army as YHO-5 for evaluation as a light observation helicopter. They were redesignated as YOH-5A before delivery in 1962. The assigned serial numbers were 62-4207/4211 although Fairchild Hiller flew a prototype with the incorrect serial 62-4206. Originally the assigned serials were 62-4206/4210 but that was changed when the YOH-4As were re-serialled due to 62-4201 having been assigned to a Lockheed VC-140. Refer also to H-5.

HO-6 Hughes 369M Specifications: rdm: 26'4", 8.03 m length: 30'4", 9.25 m engines: 1 Allison T63-A-5A max.speed: 150 mph, 241 km/h

(Source: Hughes)

Five were ordered by the US Army as YHO-6 for evaluation as a light observation helicopter. They were redesignated as YOH-6A before the first flight on 27 February 1963. The assigned serial numbers were 62-4212/4216. A further development, designated as YHO-6A, was ordered with serial 62-12624 whilst the designation HO-6A was reserved for the production version which eventually was ordered as OH-6A. Refer also to H-6

HU = Helicopter/Utility

HU-1 Bell Iroquois Specifications: HU-1A HU-1D rdm: 44', 13.41 m 48', 14.63 m length: 39'7", 12.07 m 41'11", 12.78 m engines: 1 Lycoming 1 Lycoming T53-L-1 T53-L-11 max. speed: 152 mph, 245 km/h 138 mph, 222 km/h

(Source: Bell)

The prototype having been ordered as XH-40, the HU-1A was the production version of which 182 were ordered by the US Army with serials 57-6095/6103, 58-2078/2093, 58-3017/3047, 59-1607/1716 and 60-3530/3545. On 18 September 1962 those remaining in service were redesignated as UH-1A. Various aircraft were later modified with a Lycoming T53-L-5 engine without a change of designation. The YHU-1B version, of which four were built with serials 60-3546/3549 also had the T53-L-5 engines as had the production version designated as HU-1B. The latter first flew in 1960 and 511 were ordered with serials 60-3550/3619, 61-686/803, 62-1872/2105, 62-4566/4613 and 62-12515/12555. From 18 September 1962 production continued as UH-1B whilst those remaining in service were also given that designation. The YHU-1Bs became YUH-1B. At a later date a number of aircraft were fitted with the T53-L-11 engine. At least one HU-1B (60-3606) was flown with USMC markings. The designation HU-1C was applied to a version which was eventually ordered as UH-1C. Seven prototypes of the next version were ordered as YHU-1D with serials 60-6028/6034. The first flight took place on 16 August 1961 and those remaining in service on 18 September 1962 were redesignated as UH-1D. The production version was the HU-1D of which 30 were ordered with serials 62-2106/2113 and 62-12351/12372. They were, however, delivered after that the designation had changed to UH-1D on 18 September 1962. The HU-1E version was similar to the HU-1A but had 1 Lycoming T53-A-11 engine. This was a version for the USMC and, although the first 34 examples were ordered as HU-1E, they were delivered as UH-1E after the designation had changed on 18 September 1962. Production continued using that designation. The serials for the HU-1Es were 151266/151299. The HU-1F designation was reserved for the Iroquois Warrior attack helicopter which was only built as a mock-up although serial 62-5434 has been associated with this designation. The serial 62-0255 has also been linked with this design but it was the serial applied to the mock-up. Refer also to H-40, H-48, H-1

HZ = Helicopter//Experimental

HZ-1 De Lackner DH-4 Aerocycle Specifications: diameter: 15', 4.57 m engines: 1 Kiekheafer Mercury Mk.55 max. speed: 65 mph, 104 km/h

(Source: US Army Transportation Museum)

Originally designated as YHO-2, 12 HZ-1s were ordered and presumably built and supplied. The serials were 56-6928/6939. The HZ-1 was a one man flying platform and the first one flew in January 1955. In flight the counter rotating blades flexed too much and collided, thereby causing two crashes, leading to the abandonment of the concept. It is possible that not all 12 aircraft were completed. Refer also to HO-2

VZ = VTOL/Experimental

VZ-1 Hiller Pawnee Specifications: diameter: 8', 2.44 m engines: 3 Nelson H56 max. speed: 15 mph, 24 km/h

(Source: US Army Aviation Museum)

The Hiller VZ-1 Pawnee was a flying platform fitted with a ducted fan. Flight direction was obtained by the pilot leaning into the desired direction. The craft was originally built for the Office of Naval Research to tests ducted fan type of lift and propulsion. Tests began with a twin engined prototype on 21 January 1955 with tethered flights, with a first free flight taking place on 4 February 1955. This version had a diameter of 6', 1.83 m. Tests of the US Army version, with a larger diameter and fitted with three engines and designated VZ-1, began in 1958. Two craft were ordered in November 1956 with serials 56-6944/6945 and they were initially designated as YHO-1E (in which E designated Hiller). The application proved to be limited as the vehicle could not be flown at an altitude over 1.50 m and was noisy. Refer also to HO-1

VZ-2 Vertol 76 Specifications: span: 24'11", 7.59 m length: 26'5", 8.05 m engines: 1 Lycoming YT53-L-1 max. speed: 210 mph, 340 km/h

(Source: NASA)

The Vertol 76 had the wings hinged at the rear to the top of the fuselage. For VTOL this wing was raised through to 90°. The engine was fitted in the fuselage and drove two wing mounted propellers. The VZ-2 programme was funded by the US Navy as well as the US Army and one aircraft was ordered with the serial 56-6943. It was completed in April 1957 and made its first successful conversion on 23 July 1958. Following completion of the military tests the aircraft was transferred to NASA in November 1960 and was fitted with a new type of jaw control as well as a new wing before NASA continued tests. The aircraft is now in NASM, Washington.

VZ-3 Ryan 72 Vertiplane Specifications: span: 23'5", 7.14 m length: 27'8", 8.43 m engines: 1 Lycoming T53-L-1 max. speed: 155 mph, 249 km//h

(Source: San Diego Air & Space Museum)

The Ryan 72 design used the blown surface technique to achieve the VTOL effect. The wing was fitted with giant flaps and the slipstream was also channelled by side deflectors so that in a hovering mode the flow of air generated by the large propellers, would be deflected down. These propellers were driven by a single engine in the fuselage. The programme was initiated by the US Navy and the US Army and one aircraft was ordered as VZ-3 with serial 56-6941. The aircraft was tested with a variety of tail fitted control rotors as well as a variable incidence tailplane. Taxying trials began on 7 February 1968 and were followed by a two months period of windtunnel testing. The first conventional take off took place early in 1958. The test programme lasted 6 weeks during which it is believed the aircraft performed beyond expectations with the capability to fly backwards and sideways although no vertical take-off could be performed. Nevertheless, the concept was a dead end and was not further pursued. The aircraft crashed in February 1959 and was rebuilt before being transferred to NASA as NASA235. The aircraft is now displayed in the US Army Aviation School Museum, Fort Rucker.

VZ-4 Doak 16 Specifications: span: 25'6", 7.77 m length: 32', 9.75 m engines: 1 Lycoming YT53-L-1 max. speed: 230 mph, 370 km/h

(Source: Gordon Hubbard, via 1000aircraftphotos.com photo #3860)

The Doak 16 used rotatable wing tip mounted ducted fans which were driven by a single engine in the fuselage to achieve

VTOL. The ducts could tilt 90° and housed 9 bladed propellers. The US Army ordered a single VZ-4 with serial 56-6942 which made its first flight at Torrence Municipal Airport on 25 February 1958. During a 50 hours tests programme conducted at Edwards AFB it achieved full transition in May 1959. In September 1959 the aircraft was handed over to NASA for further evaluation.

VZ-5 Fairchild M224-1 Specifications: span: 32'9", 9.98 m length: 33'8", 10.26 m engines: 1 General Electric YT58-GE-2 max. speed: 184 mph, 296 km/h

(Source: US Army)

The Fairchild M224 used deflected slipstream to achieve VTOL flight. The single engine drove four large propellers which blew air over the large flapped wings. The US Army ordered one aircraft as VZ-5 and with serial 56-6940 which flew for the first time on 18 November 1959 in a tethered mode and without an undercarriage. Further development was abandoned after limited testing.

VZ-6 Chrysler Specifications: width: 8’6”, 2.60 m length: 21'6", 5.38 m engines: 1 Lycoming GSO-480 max. speed: 70 mph, 113 km/h

(Source: US Army Aviation Museum)

A flying platform with two ducted fans of which two were ordered by the US Army as VZ-6 and with serials 58-5506/5507. Tethered flight took place in early 1959. The vehicle was underpowered and unstable and on the first untethered flight, in 1960, the aircraft flipped over. Following this the programme was cancelled.

VZ-7 Curtiss-Wright Specifications: width: 16', 4.88 m length: 17', 5.18 m engines: 1 Turbomeca Artouste IIB max. speed: 37 mph, 60 km//h

(Source: US Army)

A wingless flying platform in which the engine drove four direct lift aircrews. VTO mode was achieved by increasing the collective pitch of the airscrews. Two aircraft were ordered by the US Army as VZ-7 with serials 58-5508/5509. The former is now in the US Army Aviation School Museum at Fort Rucker.

VZ-8 Piasecki PA-59K Specifications: width: 9'5", 2.87 m length: 26'1", 7.95 m engines: 1 Turbomeca Artouste IIB max.speed: 150 mph, 241 km/h

(Source: US Army)

The Piasecki PA-59K Flying Jeep was a flying platform with two ducted rotors. The mission profile intended for the VZ-8 (as well as the VZ-6 and VZ-7) was to fly close to the ground for observation, liaison and weapons carrying missions making use of the ground cover. Designated as VZ-8 and with serial 58-5510, it was initially fitted with 2 Lycoming O-360-A2A engines and flew in this configuration on 22 September 1958. It was later fitted with the Turbomeca engine and flew for the first time on 12 November 1958. The first aircraft was also tested with floats by the US Navy and USCG and was identified by the manufacturer as model PA-59N. The second aircraft was also designated by VZ-8 and had serial 58-5511. Idenfitied by the manufacturer as model PA-59A, it had a width of 9'3", 2.82 m and a length of 24'5", 7.45 m and was fitted with 2 Turbomeca Artouste IIC engines. This aircraft flew for the first time on 28 June 1959. Later the aircraft was redesigned as the model PA-59H Airgeerp II and fitted with a canted fuselage structure. It flew for the first time in this configuration on 15 February 1962.

VZ-9 Avro Canada Avrocar Specifications: diameter: 18', 5.49 m engines: 3 Continental J69 max. speed: 300 mph, 483 km/h

(Source: Avro Canada)

The Avrocar was a flying saucer type VTOL aircraft with the three jets driving a central fan. In 1952 Avro Canada began to study designs for a supersonic circular wing fighter-bomber with funds from the Canadian government. In July 1954 the project funding was taken over by the USAF and resulted in a vehicle designated as PV-704 or Weapons System 606A. The US Army became interested in 1958 because of the possibilities in its ‘flying jeep’ requirements. Two vehicles were ordered by the US Army as VZ-9 with serials 58-7055 and 59-4975. Aircraft 58-7055 was a wind tunnel test model that was sent to NASA Ames for tests. Although some reference sources have suggested that tethered trials with this aircraft began on 5 December 1959 and its first untethered flight took place on 17 May 1961, there seems to be no evidence of such flights in more recent reference sources Aircraft 59-4975 made its first tethered flight on 29 September 1959 and its first untethered flight on 12 November 1959. These flights were undertaken at Malton, in Canada. Some reference sources have suggested that 59-4975 was cancelled. Instability above the altitude of 1.20 m led to a resumption of tethered flights and eventually the project was abandoned in December 1961. Aircraft 59-4975 is now in the US Army Transport Museum, Fort Eustis whilst 58-7055 is in the Smithsonian collection.

VZ-10 Lockheed 330 Hummingbird Specifications: span: 25'8", 7.82 m length: 32'8", 9.96 m engines: 2 Pratt & Whitney JT12A-3LH max. speed: 518 mph, 833 km/h

(Source: US Army Aviation Museum)

Two examples of the Hummingbird were ordered by the US Army as VZ-10 with serials 62-4503/4504. The first flight was made on 7 July 1962 and on 18 September 1962 they were redesignated as XV-4A. Some reference sources have suggested that the designation VZ-10 was used for Rutan VariEze aircraft but the era, about 1990, makes this unlikely. Refer also to V-4

VZ-11 Ryan Specifications: span: 29'10", 9.09 m length: 44'6", 13.56 m engines: 2 General Electric J85-GE-5 max. speed: 550 mph, 885 km/h

(Source: US Army)

Two aircraft were ordered by the US Army as VZ-11 with serials 62-4505/4506 but they were redesignated as XV-5A on 18 September 1962 and prior to the first flight. Refer also to XV-5A

VZ-12 Hawker Siddeley P1127 Kestrel Specifications: span: 22'10", 6.96 m length: 42', 12.80 m engines: 1 Bristol Siddeley Pegasus max.speed: 690 mph, 1110 km/h

Kestrel FGA.1 (Source: Hawker Siddeley)

The Kestrel development began in 1957 and the first flight was made on 21 October 1960. The US Army ordered two aircraft for evaluation as VZ-12 with serials 62-4507/4508 but the aircraft were subsequently cancelled. The US Army was interested in the Kestrel as a potential replacement for the OV-1 and, would the project have materialised, aircraft would have been built by Northrop as N-287. The project was cancelled due to inter-service mission definition, which prevented the US Army from having heavy fixed wing aircraft. Refer also to V-6