Amphibious helicopter
Encyclopedia
An amphibious helicopter is a helicopter
that is intended to rest and take off from either land or water. Amphibious helicopters are used for a variety of specialized purposes including air-sea rescue
, marine salvage
and oceanography
, in addition to other tasks that can be accomplished with any non-amphibious helicopter. An amphibious helicopter can be designed with a waterproof or water-resistant hull
like a flying boat
or it can be fitted with utility floats
in the same manner as a floatplane
.
, and they can deliver injured passengers directly to hospitals or other emergency facilities. A practical amphibious helicopter first appeared in 1941 and the water-landing feature soon proved its worth. Non-amphibious helicopters were required to hover above the scene of a water accident and utilize a hoist
but amphibious helicopters were capable of setting down on the water to effect a rescue more directly.
In 1941, Igor Sikorsky
fitted utility floats (also called pontoons) to the Vought-Sikorsky VS-300, making the first practical amphibious helicopter. In the 1940s and 1950s, some models of helicopter such as the Bell 47
and 48
and the Sikorsky R-4 and R-6
were fitted with utility floats so that they could rest on both water and land.
Pontoons can be filled with air or they can be utilized for storage of fuel or supplies. In 1949, Sikorsky produced the H-5H
with both wheels and pontoons.
. Both the S-62 and S-61 were ready for delivery in 1961. Sikorsky produced 1100 S-61s, including some that were not watertight: a longer cargo-carrying version was given rear doors and a ramp. Sikorsky licensed other manufacturers such as Agusta
, Mitsubishi
and Westland
to produce variants of the S-61.
Amphibious helicopters came into their own in the 1960s when robust boat-hulled designs were produced in quantity for military and civilian operators. Amphibious helicopters paid dividends for rescue personnel who enjoyed greater safety and success during operations. Overwater operations that used non-amphibious helicopters relied to a higher degree on hoists, rescue basket
s, and rescue swimmers. Nevertheless, beginning in the 1970s, amphibious models were steadily replaced by helicopter models unable to land on water, because of high amphibious aircraft development costs. The last amphibious helicopter model used by the United States Coast Guard
was the Sikorsky HH-3F Pelican
, retired in 1994.
Resting on the surface of the water with the rotor stopped, in conditions of brisk wind and mounting surface waves, a boat-hulled helicopter with stabilizing floats on either side is less likely to remain upright than a non-boat helicopter fitted with utility pontoons. Difficulty in lifting off can be encountered, especially when heavily loaded or in increasing seas.
The Canadian Forces operates the Ch-124 Sea King and developed the technique called water bird in landing the Sea King in water.
floats positioned amidships. The HUP-2 was able to taxi forward or backward on water, regardless of wind direction.
The CH-46 Sea Knight
and its Canadian variant, the CH-113 Labrador
, can land on water and rest for up to two hours in calm water. The rear sponson
s hold two of the three landing gear units as well as self-sealing fuel tanks. The helicopter began service with the United States Marine Corps
in 1962, and with the Canadian military in 1963, and is used to carry cargo and combat troops.
The Boeing CH-47 Chinook
was made sufficiently watertight to allow it to land on water for a short time in carrying out covert operation
s and special military missions. Buoyancy was increased with sealed compartments inside sponsons which extended most of the way along each side of the fuselage
. For extended water usage, Boeing offered a kit to enhance its water resistance. The Sikorsky CH-53 Sea Stallion
, first introduced in 1966, is also capable of limited water landing.
.
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...
that is intended to rest and take off from either land or water. Amphibious helicopters are used for a variety of specialized purposes including air-sea rescue
Air-sea rescue
Air-sea rescue is the coordinated search and rescue of the survivors of emergency water landings as well as people who have survived the loss of their sea-going vessel. ASR can involve a wide variety of resources including seaplanes, helicopters, submarines, rescue boats and ships...
, marine salvage
Marine salvage
Marine salvage is the process of rescuing a ship, its cargo, or other property from peril. Salvage encompasses rescue towing, refloating a sunken or grounded vessel, or patching or repairing a ship...
and oceanography
Oceanography
Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean...
, in addition to other tasks that can be accomplished with any non-amphibious helicopter. An amphibious helicopter can be designed with a waterproof or water-resistant hull
Hull (watercraft)
A hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present. The line where the hull meets the water surface is called the waterline.The structure of the hull varies depending on the vessel type...
like a flying boat
Flying boat
A flying boat is a fixed-winged seaplane with a hull, allowing it to land on water. It differs from a float plane as it uses a purpose-designed fuselage which can float, granting the aircraft buoyancy. Flying boats may be stabilized by under-wing floats or by wing-like projections from the fuselage...
or it can be fitted with utility floats
Floats (nautical)
Floats are airtight hollow structures, similar to pressure vessels, whose air-filled interior makes them buoyant in water. They are most often used to make up the multipart hulls of trimarans, small open catamarans, and floatplanes . Their main purpose is to supply buoyancy, not storage space...
in the same manner as a floatplane
Floatplane
A floatplane is a type of seaplane, with slender pontoons mounted under the fuselage; only the floats of a floatplane normally come into contact with water, with the fuselage remaining above water...
.
Development
Helicopters have taken a primary role in air-sea rescue since their introduction in the 1940s. Helicopters can fly in rougher weather than fixed-wing aircraftFixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...
, and they can deliver injured passengers directly to hospitals or other emergency facilities. A practical amphibious helicopter first appeared in 1941 and the water-landing feature soon proved its worth. Non-amphibious helicopters were required to hover above the scene of a water accident and utilize a hoist
Hoist (device)
A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or wire rope as its lifting medium. The load is attached to the hoist by means of a...
but amphibious helicopters were capable of setting down on the water to effect a rescue more directly.
Fitted floats
Igor Sikorsky
Igor Sikorsky , born Igor Ivanovich Sikorsky was a Russian American pioneer of aviation in both helicopters and fixed-wing aircraft...
fitted utility floats (also called pontoons) to the Vought-Sikorsky VS-300, making the first practical amphibious helicopter. In the 1940s and 1950s, some models of helicopter such as the Bell 47
Bell 47
The Bell 47 is a two-bladed, single engine, light helicopter manufactured by Bell Helicopter. Based on the third Model 30 prototype, Bell's first helicopter designed by Arthur M. Young, the Bell 47 became the first helicopter certified for civilian use on 8 March 1946...
and 48
Bell H-12
-See also:-References:* Andrade, John M. U.S.Military Aircraft Designation and Serials since 1909. Leicester, UK: Midland Counties Publications, 1979. ISBN 0-904597-22-9....
and the Sikorsky R-4 and R-6
Sikorsky R-4
The Sikorsky R-4 was a two-place helicopter designed by Igor Sikorsky with a single, three-bladed main rotor and powered by a radial engine. The R-4 was the world's first large-scale mass-produced helicopter and the first helicopter to enter service with the United States Army Air Forces, Navy, and...
were fitted with utility floats so that they could rest on both water and land.
Pontoons can be filled with air or they can be utilized for storage of fuel or supplies. In 1949, Sikorsky produced the H-5H
Sikorsky H-5
The Sikorsky H-5, is a helicopter built by Sikorsky Aircraft Corporation, formerly used by the United States Air Force, and its predecessor, the United States Army Air Forces, as well as the United States Navy and United States Coast Guard The Sikorsky H-5, (aka R-5, S-51, HO3S-1, or Horse) (R-5...
with both wheels and pontoons.
Boat hull design
The Sikorsky S-62 Seaguard was the first amphibious helicopter made with a flying boat hull—the prototype flew in 1958. Utilizing many components of the earlier S-55, the S-62 proved the idea, and Sikorsky flew their S-61 Sea King prototype in 1959 for the U.S. Navy, a model intended for anti-submarine warfareAnti-submarine warfare
Anti-submarine warfare is a branch of naval warfare that uses surface warships, aircraft, or other submarines to find, track and deter, damage or destroy enemy submarines....
. Both the S-62 and S-61 were ready for delivery in 1961. Sikorsky produced 1100 S-61s, including some that were not watertight: a longer cargo-carrying version was given rear doors and a ramp. Sikorsky licensed other manufacturers such as Agusta
Agusta
Agusta is an Italian helicopter manufacturer. It is based in Samarate, Northern Italy. It is a subsidiary of Finmeccanica. The company was founded by Count Giovanni Agusta in 1923, who flew his first airplane in 1907...
, Mitsubishi
Mitsubishi
The Mitsubishi Group , Mitsubishi Group of Companies, or Mitsubishi Companies is a Japanese multinational conglomerate company that consists of a range of autonomous businesses which share the Mitsubishi brand, trademark and legacy...
and Westland
Westland Aircraft
Westland Aircraft was a British aircraft manufacturer located in Yeovil in Somerset. Formed as a separate company by separation from Petters Ltd just before the start of the Second World War, Westland had been building aircraft since 1915...
to produce variants of the S-61.
Amphibious helicopters came into their own in the 1960s when robust boat-hulled designs were produced in quantity for military and civilian operators. Amphibious helicopters paid dividends for rescue personnel who enjoyed greater safety and success during operations. Overwater operations that used non-amphibious helicopters relied to a higher degree on hoists, rescue basket
Helicopter rescue basket
A helicopter rescue basket is a basket suspended below a helicopter in order to rescue people from a fire or other disaster site.-Uses:There are two main types of helicopter baskets. The smaller, more common type is used by rescuers to lift a person up from ground or water into the helicopter.The...
s, and rescue swimmers. Nevertheless, beginning in the 1970s, amphibious models were steadily replaced by helicopter models unable to land on water, because of high amphibious aircraft development costs. The last amphibious helicopter model used by the United States Coast Guard
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...
was the Sikorsky HH-3F Pelican
Sikorsky S-61R
The Sikorsky S-61R is a twin-engine helicopter used in transport or search and rescue roles. A developed version of the S-61/SH-3 Sea King, the S-61R was also built under license by Agusta as the AS-61R...
, retired in 1994.
The Canadian Forces operates the Ch-124 Sea King and developed the technique called water bird in landing the Sea King in water.
Limited water capability
Helicopters can be designed to withstand limited contact with the surface of a body of water. The 1958 Vertol HUP-2 was an amphibious development of the twin-rotor Piasecki H-25 which strengthened its hull and replaced lower nose windows with tough aluminum. The HUP-2 was provided with a pair of stabilizing outriggerOutrigger
An outrigger is a part of a boat's rigging which is rigid and extends beyond the side or gunwale of a boat.In an outrigger canoe and in sailboats such as the proa, an outrigger is a thin, long, solid, hull used to stabilise an inherently unstable main hull. The outrigger is positioned rigidly and...
floats positioned amidships. The HUP-2 was able to taxi forward or backward on water, regardless of wind direction.
The CH-46 Sea Knight
CH-46 Sea Knight
The Boeing Vertol CH-46 Sea Knight is a medium-lift tandem rotor transport helicopter, used by the United States Marine Corps to provide all-weather, day-or-night assault transport of combat troops, supplies and equipment. Assault Support is its primary function, and the movement of supplies and...
and its Canadian variant, the CH-113 Labrador
CH-113 Labrador
|-See also:-External links:* * * *...
, can land on water and rest for up to two hours in calm water. The rear sponson
Sponson
Sponsons are projections from the sides of a watercraft, for protection, stability, or the mounting of equipment such as armaments or lifeboats, etc...
s hold two of the three landing gear units as well as self-sealing fuel tanks. The helicopter began service with the United States Marine Corps
United States Marine Corps
The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...
in 1962, and with the Canadian military in 1963, and is used to carry cargo and combat troops.
The Boeing CH-47 Chinook
CH-47 Chinook
The Boeing CH-47 Chinook is an American twin-engine, tandem rotor heavy-lift helicopter. Its top speed of 170 knots is faster than contemporary utility and attack helicopters of the 1960s...
was made sufficiently watertight to allow it to land on water for a short time in carrying out covert operation
Covert operation
A covert operation is a military, intelligence or law enforcement operation that is carried clandestinely and, often, outside of official channels. Covert operations aim to fulfill their mission objectives without any parties knowing who sponsored or carried out the operation...
s and special military missions. Buoyancy was increased with sealed compartments inside sponsons which extended most of the way along each side of the fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
. For extended water usage, Boeing offered a kit to enhance its water resistance. The Sikorsky CH-53 Sea Stallion
CH-53 Sea Stallion
The CH-53 Sea Stallion is the most common name for the Sikorsky S-65 family of heavy-lift transport helicopters. Originally developed for use by the United States Marine Corps, it is also in service with Germany, Iran, Israel, and Mexico...
, first introduced in 1966, is also capable of limited water landing.
Roles
Amphibious helicopters have been used in a variety of roles, including transporting the US presidentMarine One
Marine One is the call sign of any United States Marine Corps aircraft carrying the President of the United States. It usually denotes a helicopter operated by the HMX-1 "Nighthawks" squadron, either the large VH-3D Sea King or the newer, smaller VH-60N "WhiteHawk", both due to be replaced by the...
.
Examples of amphibious helicopters
Boat-hulled:- Aérospatiale Super FrelonAérospatiale Super FrelonThe Aérospatiale SA 321 Super Frelon is a three-engined heavy transport helicopter produced by Aérospatiale of France. The helicopter is still in use in China where the locally produced version is known as the Z-8. "Frelon" is French for hornet....
- Mil Mi-14Mil Mi-14|-See also:-External links:******...
- Sikorsky S-62
- Sikorsky SH-3 Sea King
- Sikorsky S-61Sikorsky S-61The Sikorsky S-61L and S-61N are civil variants of the successful SH-3 Sea King helicopter. They are two of the most widely used airliner and oil rig support helicopters built.-Design and development:...
- Sikorsky CH-124 Sea King
- Sikorsky HH-3F PelicanSikorsky S-61RThe Sikorsky S-61R is a twin-engine helicopter used in transport or search and rescue roles. A developed version of the S-61/SH-3 Sea King, the S-61R was also built under license by Agusta as the AS-61R...
- Westland Sea KingWestland Sea KingThe Westland WS-61 Sea King is a British licence-built version of the American Sikorsky S-61 helicopter of the same name, built by Westland Helicopters. The aircraft differs considerably from the American version, with Rolls-Royce Gnome engines , British made anti-submarine warfare systems and a...