Largest Helicopter in
the World
The article you mention
discusses several of the largest planes
in the world. It also describes how aircraft are typically ranked by weight
rather than by physical dimensions like length or wingspan. The same holds true
for helicopters. Although the diameter of the rotor is often a useful measure
of a helicopter's size, these vehicles are most often ranked by maximum takeoff
weight. As was also true of the largest planes, the ranks of largest
helicopters are largely dominated by craft originally built in the Soviet
Union. Perhaps that should be no surprise given the vast size of that nation
and the need to transport large cargoes to distant and remote locations.
1. Mil V-12 : 231,485 lb (105,000 kg)
The largest helicopter ever built was a
massive aircraft developed in the Soviet Union during the 1960s called the Mil
V-12. The V-12 was a rather unusual test vehicle that featured two rotors
mounted side by side at the ends of a large wing. Each rotor had a diameter of
nearly 115 ft (35 m). The helicopter was so enormous that the distance from the
edge of one rotor disk to the other was almost 220 ft (67 m), even wider across
than the wingspan of a Boeing 747!
Mil V-12, largest helicopter in the world
Even more remarkable was the lifting
capacity of this powerful craft. The V-12 had a maximum takeoff weight of
231,485 lb (105,000 kg), nearly twice that of the second largest helicopter,
and set a record in 1969 for carrying a payload of 88,635 lb (40,205 kg). So
massive was the V-12 that this payload weight alone is greater than the maximum
takeoff weight of the third biggest helicopter in the world! These impressive
figures have earned the V-12 the record as the world's largest helicopter
according to the FAI and the Guinness Book of World Records.
Only two V-12 prototypes were built, yet
despite its amazing size and lifting power, the design was considered a failure
by its manufacturer and Soviet authorities. The V-12 was simply too big and
difficult to maneuver to be a practical machine. A production model would have
been called the Mi-12, but these plans were cancelled following evaluation of
the two test vehicles. One of the V-12 prototypes was retired to the Russian
Air Force Museum in Monino while the second is reportedly housed at the Mil
factory near Moscow.
2. Mil Mi-26 : 123,455 lb (56,000 kg)
Because the V-12 had been judged
unsatisfactory, Mil was again tasked with designing a large heavy-lift
helicopter for military and civil use. The resulting Mi-26 was far more compact
than the V-12 due to advancements in propulsion technology, making the Mi-26
much less cumbersome to operate. With a maximum takeoff weight of 123,455 lb
(56,000 kg), the Mi-26 is the world's second largest helicopter overall and the
largest ever to go into production as well as the largest flying today.
Mil Mi-26 recovering an American CH-47 Chinook helicopter
Though substantially smaller than the V-12,
the Mi-26 carries a considerable payload up to 44,000 lb (20,000 kg). The Mi-26
has proven much more powerful and efficient than its predecessors thanks in
part to its eight-bladed main rotor. This rotor is only 106 ft (32 m) in
diameter compared to the 115 ft (35 m) diameter rotors used aboard other giant
Russian helicopters but can lift greater loads due to improvements in engines
and blade design. Over 200 examples of the Mi-26 were built and the type
remains in use throughout Russia. Several have also been sold to civilian firms
and foreign nations.
3. Mil Mi-6 : 97,000 lb (44,000 kg)
The third and fourth largest helicopters are
also Mil designs that helped prepare the way for the V-12 and Mi-26. The
Soviet's first attempt to create an enormous heavy-lift helicopter came during
the mid-1950s with the introduction of the Mi-6. Designed for many of the same
duties as the improved Mi-26 some 25 years later, the Mi-6 had a maximum
takeoff weight of 97,000 lb (44,000 kg) and could carry up to 24,250 lb (11,000
kg) of payload. The rotor used on the Mi-6 was the same 115 ft (35 m) diameter
rotor system that would also be used on the V-12.
Mil Mi-6 lifting a large payload
The Mi-6 was the world's largest helicopter
when it was first built and retained the title for many years until the
appearance of the V-12. This Mi-6 proved quite successful for its time as
demonstrated by the large number built. Some 860 were manufactured between 1960
and 1981 primarily for the Soviet Air Force and the civil airline Aeroflot.
Additional models were also exported to several Soviet allies. These
helicopters remained in use for over 40 years but are finally being phased out.
In spite of its age, the Mi-6 still remains a remarkable vehicle and one of the
largest helicopters ever conceived.
4. Mil Mi-10 : 83,775 lb (38,000 kg)
Yet another member of this related family of
giant helicopters was the Mi-10. The Mi-10 was a specialized variant of the
Mi-6 called a flying crane. The Mi-10 borrowed the engine and dynamic systems
of the Mi-6 but these were mounted within a new fuselage. Unlike the wide Mi-6
fuselage that featured hinging doors for loading cargo internally, the Mi-10
fuselage was instead configured for passengers. This fuselage stood atop four
widely spaced, extended-length landing gear legs designed to straddle large,
bulky payloads carried below the helicopter.
Mil Mi-10 showing its long landing gear legs
Both the Mi-6 and Mi-10 shared the same 115
ft (35 m) diameter rotor that was also used aboard the V-12. Compared to the
Mi-6, however, the Mi-10 had a reduced maximum takeoff weight of 83,775 lb
(38,000 kg) ranking it as the fourth largest helicopter ever built. Only about
55 Mi-10 helicopters were made and the type saw relatively little use. Both its
flying crane mission and the transport duties of the Mi-6 have since been taken
over by the far superior Mi-26.
5. Sikorsky CH-53E : 73,500 lb (33,340
kg)
Coming in as the fifth largest helicopter in
the world is the biggest ever built in the United States, the Sikorsky CH-53E
Super Stallion. The CH-53E is an enlarged model of the earlier CH-53 Sea
Stallion. Both vehicles were originally developed as heavy-lift helicopters for
the US Marine Corps, and they have also been used by the Navy, Air Force, and
allied countries. The largest variant of the CH-53 family developed so far is
the CH-53E with a maximum takeoff weight of 73,500 lb (33,340 kg). Though
comparable in physical dimensions to other H-53 models with a main rotor 79 ft
(24.1 m) in diameter, the CH-53E and related MH-53E are equipped with an extra
engine of increased power to lift a significantly greater payload.
CH-53E Super Stallion lifting an F-15 Eagle fighter
Approximately 115 examples of the CH-53E and
MH-53E Sea Dragon variant were built, and these remain the largest helicopters
in military service in the West. However, a new version of the venerable H-53
design is currently under development. Known as the CH-53K, this improved model
will carry more powerful engines and new rotor blades to increase maximum takeoff
weight to 84,700 lb (38,420 kg). Once this enhanced variant becomes available,
the CH-53K should narrowly beat the Mi-10 to become the world's fourth largest
helicopter.
6. Boeing Vertol MH-47E/G : 54,000 lb
(24,495 kg)
The next largest helicopter is the Boeing
Vertol CH-47 Chinook also developed in the United States. The H-47 family began
development during the late 1950s as an enlarged variant of the CH-46 Sea
Knight and has proven to be one of the most successful series of military
heavy-lift helicopters. The design features a long, spacious fuselage powered
by two engines driving a pair of tandem rotors 60 ft (18.3 m) in diameter. The
type is widely used for transporting troops, carrying heavy military equipment
like artillery slung underneath the fuselage, and resupply missions. Though the
primary users are the US Army and British Royal Air Force, the CH-47 has been
sold to over 20 nations as well as civilian operators.
Tandem rotor design of the MH-47E Chinook
The single largest versions of the H-47
developed to date are the MH-47E and MH-47G special operations models. While
most CH-47 variants have a maximum takeoff weight around 50,000 lb (22,680 kg),
the MH-47E/G have been upgraded to 54,000 lb (24,495 kg). Over 1,000 Chinooks
have been built to date and production of newer CH-47F, MH-47G, and HH-47
models continues today.
7. Hughes XH-17 : 50,000 lb (22,680 kg)
Coming in as the seventh largest helicopter
is a unique prototype called the XH-17 Sky Crane. The Sky Crane was the first
helicopter built by Hughes Aircraft, the same company that had also built the
behemoth Spruce Goose flying boat during the 1940s. Shortly thereafter, Howard
Hughes became interested in helicopter technology and purchased a design for a
giant transport helicopter from the Kellett company. Similar to the Russian
Mi-10, the Sky Crane and was equipped with four long landing gear legs to
straddle large oversized payloads carried underneath the fuselage. The H-17 was
lifted by a massive two-blade rotor system 134 ft (40.8 m) across, still the
record for the largest rotor ever flown.
Massive rotor of the Hughes XH-17 Sky Crane
Construction of a single XH-17 prototype
began during the late 1940s for use as a research vehicle. The craft was
completed by 1952 when it began a three-year testing period. The maximum takeoff
weight ever attempted aboard the Sky Crane was over 50,000 lb (22,680 kg)
during a flight in 1953. However, the research program concluded that the
design was too large and cumbersome to be useful and no further models were
built. Hughes also designed an enlarged variant called the H-28 that would have
doubled the maximum weight to nearly 104,000 lb (47,000 kg), but further
development was cancelled following experience with the XH-17.
8. Sikorsky CH-54 : 47,000 lb (21,320 kg)
Rounding out this list of large helicopters
is another American design called the Sikorsky CH-54 Tarhe. Like the Mi-10 and
XH-17, the CH-54 was a flying crane helicopter designed to haul large payloads
slung below the fuselage. The unusual looking helicopter featured an upper
spine containing the engines driving the 72 ft (21.9 m) diameter main rotor. At
the front of this spine was the cockpit with windows facing both forward and
aft allowing crew to monitor the payload. This minimal fuselage structure made
the CH-54 a very efficient design compatible with various cargo modules that
could be hoisted into position behind the cockpit for low drag.
CH-54 Tarhe recovering a damaged F-4 Phantom II
With a maximum takeoff weight of 47,000 lb
(21,320 kg), the CH-54 was designed primarily for transporting military cargoes
like artillery, ground vehicles, and other bulky supplies. Its lifting
capabilities were frequently used during the Vietnam War to move aircraft or
recover downed planes and helicopters. A civil model called the S-64 Skycrane
was also developed and became popular with the logging industry and for
firefighting. About 105 of these helicopters were built, and though retired
from military service, several remain in civilian use.
Summary
Further illustrating just how large the
helicopters described above are is the fact that no other helicopter exceeds a
maximum weight of 35,000 lb (15,875 kg). The majority of helicopters are indeed
quite small next to these giants since there is relatively little demand for
such enormous vehicles compared to more moderately sized designs. Yet even
among these giants, the size differential between them is hard to comprehend.
The following diagram compares the Russian V-12 and Mi-26 to the American
CH-53E. Despite its enormous size relative to any other Western helicopter, the
Super Stallion almost seems a toy next to the two largest helicopters ever
built.
Relative size comparison of the V-12, Mi-26, and CH-53E
To learn more about helicopters in general
and giants like the Mi-26 or CH-53, you may enjoy the books Helicopters: Military, Civilian, and Rescue Rotorcraft
by Robert Jackson or Steve Crawford's Twenty-First Century Military Helicopters.
- answer by Molly Swanson,
10 December 2006
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