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MD
HELICOPTERS
HUGHES 500 C |
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En
1960, el Departamento de Defensa de los Estados Unidos publica una
Especificación Técnica por un helicóptero liviano de observación
(LOH) capaz de cubrir varios roles tales como: transporte de personal,
escolta y misiones de ataque, evacuación y observación. Se
presentaron 12 empresas en la contienda, enviando Hughes el MODELO
369. A su vez Hiller envió el Modelo FH-1100 y la Bell a su Modelo
206, siendo preseleccionados estas dos aeronaves como finalistas,
pero el US Army posteriormente incluyo al 369, el cual fue
ofrecido a muy bajo costo, bajo la designación OH-6, ordenándose
cinco prototipos en la primavera de 1961. El modelo de la Bell fue
posteriormente eliminado y el modelo de la Hughes fue redesignado como OH-6A
"Cayuse". El primero de los cinco prototipos voló por
primera vez el 27 de febrero de 1963 y fue enviado a la Base de Fort
Rucker en noviembre para comenzar con las pruebas del Ejército. La aeronave
era muy interesante desde el punto de vista estructural. Por ejemplo, el
rotor totalmente articulado, constaba de cuatro palas y cuerda
constante de una sola lámina de aluminio. El fuselaje de aleación
ligera, semi-monocoque y de remarcable robustez, le proveían buena
protección a los ocupantes en caso de aterrizajes duros. Sin embargo,
lo compacto del fuselaje y su pequeño volumen interno no le conferían
mucha comodidad a los pasajeros traseros. La aeronave
estaba provista de una turbina Allison 250, liviana y compacta, de 317
SHP. La elección para la construcción a gran escala del OH-6 A
fue anunciada en mayo de 1965, con una orden inicial de 714 unidades,
las cuales serían incrementadas a 1300 con opción de otras 114 más.
La producción alcanzó un máximo de 70 helicópteros en el primer mes.
De las 1434 unidades construidas, las últimas fueron entregadas en
agosto 1970. El Cayuse
estableció 23 records mundiales entre marzo y abril de 1966: 2800
Km. en circuito cerrado, 3561 Km. en línea recta, 227,7 Km/h en
circuito cerrado de 2000 Km. y una altitud de 8601 Metros. Ganó también
otros records en diferentes clases de helicópteros. Además de
los cinco prototipos construidos para el US Army, Hughes construyó
otros cuatro para sus propias pruebas, uno de los cuales fue convertido
a la versión civil, denominada MODELO 500, el cual voló por
primera vez en 1967. El modelo posterior, 500C constaba de una
turbina Allison 250-C20 de mas potencia (400 SHP). Uno de los OH-6 A
fue posteriormente modificado bajo el programa ARPA (sistema avanzado de
investigación del Departamento de Defensa) para reducir el nivel de
ruido, teniendo el sobrenombre de "The Quiet One". Se le
introdujo un rotor de cinco palas, un rotor de cola de cuatro palas,
silenciador en el escape y diferentes dispositivos en las entradas de
aire. El nuevo rotor tenía un 67 por ciento mas de RPM que el original,
permitiéndole 270 Kg. mas de carga paga. Un segundo prototipo
experimental, el OH-6C, con turbina Allison 250-C20, alcanzó la
velocidad de 322 Km/h durante un vuelo de pruebas en la Base Aérea de
Edwards. El H-500MC
fue una versión de exportación del Hughes 500C, con
mejoras, incluido un rotor principal de mayor diámetro, una caja
de transmisión mayor, palas del rotor de cola totalmente metálicas
y capacidad de combustible de 242 litros. Las ventanas eran diferentes y
se lo podía cambiar el tren de aterrizaje por uno mas alto. El
armamento era similar al OH-6A. El Hughes
ha sido exportado a diferentes fuerzas armadas de muchos países como
Brasil, Argentina, Bolivia, México, etc. Fue
construido bajo licencia en Argentina por la firma RACA, en Japón por
Kawasaki, en Corea del Sur por Korean Air y en Italia por Breda-Nardi. |
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In
1960, the US Department of Defense issued Technical Specification 153 for
a Light Observation Helicopter (LOH) capable of fulfilling various roles:
personnel transport, escort and attack missions, casualty evacuation and
observation. Twelve companies took part in the competition and Hughes
submitted the Model 369, nicknamed the "flying egg" on
account of its shape. The Hiller and Bell
aircraft were selected as finalists, but the US Army later included the
Hughes helicopter as well — which was offered at an exceptionally low
price — under the designation OH-6, and five prototypes were
ordered in spring 1961. The Bell was subsequently eliminated from the
contest and the Hughes 369 was redesignated OH-6A
"Cayuse". The first of the five prototypes flew on 27
February 1963 and was delivered to Fort Rucker air base the following
November, to begin trials for the Army. The Hughes aircraft was very interesting from a
structural point of view. For example, the fully-articulated rotor had
four blades of constant chord, consisting of an extruded light alloy spar,
to which a single sheet of light alloy was bonded to form the profile of
the blade. The fuselage had a light alloy, semi-monocoque structure and
its remarkable robustness afforded the occupants good protection even in
heavy landings. However if the compactness of the fuselage made the Hughes
OH-6 light and sturdy, with low drag, it reduced the helicopter's
versatility, as its small internal volume was clearly restrictive, despite
being perfectly in accordance with Technical Specification 153. The aircraft had an Allison 250 turbine engine,
which was very light and compact, with a maximum power derated from 400 to
282shp, which afforded obvious advantages in terms of service life and
safety. The sophisticated avionics included a track indicator, VHF and UHF
transceivers and ADF. A wide choice of weapons fits was available. Following trials, the choice of the OH-6A for
large-scale production was announced in May 1965 with an initial order for
714, which was later increased to 1300 with an option on another 114.
Production reached a maximum of 70 helicopters in the first month. In all
1434 were built, the last of which were delivered in August 1970. The Cayuse established no fewer than 23 world
records in March-April 1966: 2800km closed circuit; 3561km in a straight
line; 227.7km/h over a 2000km closed circuit and 8601m altitude in
horizontal flight. It won other records in the various classes for
helicopters of a variety of weights, including a speed record of over
277km/h. Apart from the five prototypes built for the US
Army, Hughes built four others for its own research purposes, one of which
was converted into a civil version designated Model 500, which flew
at the beginning of 1967. The subsequent Model 500C variant had a
405shp Allison 250-C20 turbine. One OH-6A was later modified under
a research programme for ARPA (the advanced research office of the US
Department of Defense) to reduce noise levels and has been nicknamed
"The Quiet One". It introduced a five-blade main rotor,
four-blade anti-torque rotor, exhaust silencer and various noise
blanketing devices on the air intakes. The new rotor has 67 per cent of
the r.p.m. of the original one, allowing 270kg more payload to be carried
at a maximum speed of 278km/h. A second experimental prototype, the OH-6C,
with an Allison 250-C20 turbine, reached a speed of 322km/h during a test
flight from Edwards Air Force Base. The H-500MC was a military export version of
the Hughes 500C, with major improvements including a more powerful
main rotor of larger diameter transmission capable of withstanding higher
torque values, an all-metal tail rotor and a maximum fuel capacity of 242
liters. The side windows are also different and high skid landing gear can
be fitted. The armament is similar to that of the OH-6A. Hughes OH-6A helicopters have been exported
to the Brazilian Air Force (9) and Navy (6), and the Japanese Ground
Self-Defense Force (29). The 500M version has been supplied to the
Colombian Air Force (4), Italian customs (over 60), the Spanish Navy (6 in
the ASW version), Denmark, Argentina, Bolivia, Mexico and the Philippines. Was also built with license in Argentina by RACA,
in Japan by Kawasaki , in South Korea by Korean Air and in
Italy by Breda - Nardi A later version, the 500D (500MD
military) is distinguished externally from earlier models by a T-tail and
five-blade rotor. The powerplant is also different — an Allison 250-C20B
delivering an absolute maximum of 411shp and 355shp maximum continuous
power. The increase in power and adoption of the new tail unit have led to
a general improvement in structural robustness, particularly of the
landing gear, the lower part of the cabin and tail boom, plus, of course,
the transmission. Current production includes the 500E, which
introduces a lengthened and redesigned cabin among other improvements, and
the 530F which introduces an uprated Allison 250-C30 engine for
high altitude operations. Military variants of these new versions were
introduced in 1984. One of the most important orders for Hughes
helicopters was for 29 of the Model 369HM built under license by
Kawasaki and delivered to the Japanese Army in January 1972. The Japanese OH-6J
is virtually identical to the American OH-6A, except for its
performance and weight, which are conditioned by the 318shp
Mitsubishi-Allison 250-C18A powerplant. In Italy, Breda-Nardi have held the license to build and market Hughes Model 300 and 500 helicopters since 1969. Apart from various commercial orders, Breda-Nardi has supplied the NH-500M to the Italian customs. Its characteristics are the same as those of the American aircraf. |
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Characteristics |
Information |
Characteristics |
Information |
First
Flight Primer Vuelo |
196? |
Engine Motor |
1
Allison |
Seating
Capacity Plazas |
1 / 4 |
Power Potencia |
400 shp |
Empty
Weight Peso Vacío |
1105 Lb |
Hover
Ceiling O.G.E. Estacionario O.G.E |
6700 Ft |
Maximum
Weight Peso Máximo |
2550 Lb |
Hover
Ceiling I.G.E. Estacionario I.G.E |
13000 Ft |
Vel.
Cruise Vel. crucero |
110 Kts |
Service
Ceiling Techo de Servicio |
15000 Ft |
V.N.E. V.N.E |
130 Kts |
Maximum
Range (Std) Alcance (Std) |
301 NM |
Dimensions / Dimensiones |
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Fuselage
Length Fuselaje Largo |
23,00 ft |
Main
Rotor Diameter Diam. Rotor Principal |
26,33 ft |
Length,
Rotors Turning Dist. Rotores Girando |
30,31 ft |
Tail
Rotor Diameter Diam. Rotor de Cola |
4,25 ft |
Total
Height Alto Total |
8,50 ft |
Price Precio |
U$S 250000 |
Copyright © 1999 / 2003