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Bell UH-1 "Huey"
The most famous helicopter in the world
is the Bell UH-1 Iroquois, most commonly referred to as the "Huey." The
Huey, which first flew in 1956, serves in front-line service in the U.S.
military and the militaries of many nations and will continue to do so for
many years to come. It earned its fame during the Vietnam War and has been
featured in many war movies, including Apocalypse Now and
Platoon, as well as in numerous action adventure films.
The Huey has several distinctive
characteristics, including its rounded nose, its twin-bladed rotor, and
the loud "whomp whomp" sound it makes in flight. It is a particularly
noisy helicopter because, when in forward flight, the tip of the advancing
rotor blade breaks the speed of sound, creating a small sonic boom.
The first helicopters, such as the
Sikorsky R-4 and S-51, were powered by piston engines. By the early 1950s,
turbine engines were being used in many fixed-wing aircraft and helicopter
designers began to consider using them for helicopters. Turbines were
lightweight and provided more power than piston engines, but were more
expensive. The first Bell helicopter to use a turbine engine was a
modified Model 47 designated the XH-13F and flown in October 1954. In
early 1955, the Army awarded Bell a contract to develop the next
generation turbine-powered medevac helicopter, designated the XH-40 and
soon named the Model 204. The first XH-40 flew on October 22, 1956. Two
more prototypes were built in 1957, and eighteen more YH-40 service test
aircraft in 1958. Bell actively marketed the craft for more than the
narrow medevac role, and the pre-production aircraft proved so popular
among servicemen who were used to piston-powered aircraft that the Army
soon ordered even more of the craft. The Huey was the first
turbine-equipped U.S. helicopter to go into production. Production model
HU-1As entered service with the 101st Airborne at Fort Lewis, Washington.
Although they were intended for evaluation only, the Army quickly pressed
them into operational service.
The helicopter was originally designated
the HU-1A, which is where it received its name "Huey." The official U.S.
Army designation Iroquois (Army helicopters are traditionally given Native
American names) was almost never used in practice. The HU-1B was equipped
with revised main rotor blades and could carry seven passengers. These
versions were re-designated UH-1A and UH-1B respectively, in 1962. A UH-1C
version with a more powerful engine soon followed.
The
famous "Huey" helicopter.
The Huey saw combat in Vietnam in 1962,
first as a troop transport and medevac helicopter and later as an armed
assault helicopter used to protect troop transports. The Army was just
beginning to develop its "air mobility" concept. Instead of fighting an
enemy along established front lines, troops would now be taken into and
removed from combat by helicopter and dropped at key strategic positions
such as enemy escape routes. The nimble, capable Hueys flew escort with
larger, slower Piasecki H-21 Flying Bananas.
U.S.
helicopters arriving to air lift Vietnamese government Rangers of the 43rd
battalion
into battle against Viet Cong guerrillas, Saigon, 1965.
This was a revolutionary form of combat
that was not without its problems. As soon as the Viet Cong chose to hold
their ground rather than flee at the arrival of the helicopters, they
discovered the helos could be brought down with small arms fire. The H-21
proved particularly vulnerable. During one disastrous battle at Ap Bac
near Saigon in January 1963, four H-21s and one armed Huey were lost to
enemy fire. Nevertheless, the U.S. Army soon fully embraced air mobility,
but helicopters remained vulnerable to ground fire. By 1973, approximately
2,500 Hueys had been lost in Vietnam, roughly half to combat and the rest
to operational accidents.
Several thousand of the early Huey
variants were produced. Beginning in 1963, the U.S. Army ordered the first
of the improved Model 205/UH-1D Hueys. Its primary modification was the
addition of an enlarged and stretched main cabin and more powerful engine
to boost carrying capacity. More than 2,500 of this model entered service
with the U.S. armed forces, culminating in the UH-1H version. A single
Textron Lycoming T53-L-13 turboshaft engine with 1,400 shaft horsepower
(1,044 kilowatts) powered the UH-1H. The craft was 41 feet 9 inches (12.7
meters) long, 14 feet 5 inches (4.4 meters) high, and had a rotor diameter
of 48 feet (14.6 meters). It weighed 5,210 pounds (2,363 kilograms) empty,
had a maximum speed of 127 miles per hour (204 kilometres per hour) and a
range of 276 nautical miles (511 kilometres).
The
Bell Huey UH-1H was an improved model that had an enlarged main cabin and
more powerful engine.
The U.S. Marine Corps wanted a more
powerful version of the Huey equipped with two engines. The Marines were
concerned that an engine failure over water would result in a crash.
Helicopters are notoriously difficult aircraft to escape from, for they
immediately turn upside down upon hitting the water. In 1968, Bell
proposed the first twin-engine Huey. The U.S. Air Force took delivery of
the first aircraft, designated UH-1N, in 1970, and it soon became the
standard utility helicopter of the Marine Corps. It was also exported in
large numbers and eventually manufactured in Canada. The UH-1N could be
easily distinguished from the earlier models by its slightly pointed nose.
Despite its two engines, the UH-1N was slightly slower than the UH-1H. An
armed helicopter called the HueyCobra (often simply called the Cobra) used
the engine, rotors, and many other systems from the Huey. It had a slender
fuselage carrying a two-person crew, and numerous weapons.
The Huey was enormously successful for
three reasons. First, it achieved an ideal mix of cabin room, speed, and
lifting capability. Earlier piston-engine helicopters simply lacked enough
power for many military missions. Second, the Huey proved to be a rugged
and reliable helicopter in service. In addition, large military orders
enabled Bell to offer the Huey both commercially and overseas at an
attractive price.
Bell also built commercial versions of
the military Hueys beginning in 1960, and developed upgraded models such
as the 214 and 412 for military export and civilian use. The Model 412 was
equipped with a four-bladed rotor and more powerful engines and was still
being produced at Bell Helicopter Canada in 2000.
Bell and licensed firms like Italy's
Agusta (eventually bought by Bell) have built more than 15,000 Hueys. It
is the most numerous helicopter ever built and the most numerous aircraft
built since 1945 except for the Soviet-era Antonov An-2 biplane transport.
The Huey is operated by more than 60 air forces throughout the world in a
wide variety of roles, everything from VIP transport to flying ambulance
to attack helicopter. It has continued in service well past the five
decades since the first Huey lifted off the ground.
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