The Kaman HH-43 Huskie is a helicopter developed and produced by the American rotorcraft manufacturer Kaman Aircraft.[2] It is perhaps most distinctive for its use of twin intermeshing rotors, having been largely designed by the German aeronautical engineer Anton Flettner.
First flown on 21 April 1953, the HH-43 went into production and was operated by several military air services, including the United States Air Force, the United States Navy and the United States Marine Corps. It was primarily intended for use in aircraft firefighting and rescue in the close vicinity of air bases, but was extensively deployed during the Vietnam War. It was used as a search and rescue platform, having often been enhanced with makeshift modification and new apparatus to better suit the tropical conditions. The HH-43 was also exported to several other countries and sold commercially. It set several aviation records in its class, and was first helicopter to experiment with twin-turbine engines. The early models used a flat six or Wasp radial piston engine, and then this was changed to single gas turbine engine. The early piston powered models had three fins on a twin tail, but the turbine model had 4 vertical tail fins on two tail booms and an engine exhaust tube. By the 1970s, it was being replaced by newer rotorcraft that were typically bigger and capable of greater performance. Many of the helicopters made their way to the civilian market and museums.
Under the aircraft designation system used by the U.S. Navy pre-1962, Navy and U.S. Marine Corps versions were originally designated as the HTK, HOK or HUK, for their use as training, observation or utility aircraft, respectively. The Air Force Version was the H-43A, however after 1962 the designation system was consolidated, and that became the HH-43A, and the H-43B, the HH-43B. HUK-1 became UH-43C, HOK-1 became OH-43D, and HTK-1 became TH-43E. The TH-43E was a training version used by the Navy, powered by flat six piston engine, with space for three people; this version had 3 vertical tail fins on the end of single, not twin tail boom.
Development
HOK-1 prototype, 1953HUK-1 (later renamed UH-43C) on sea trials in 1959.
In 1947, the German aeronautical engineer Anton Flettner was brought to the United States as part of Operation Paperclip.[3] He was the developer of the two earlier synchropter designs from Germany during the Second World War: the Flettner Fl 265 which pioneered the synchropter layout, and the slightly later Flettner Fl 282Kolibri ("Hummingbird"), intended for eventual production. Both designs used the principle of counter-rotating side-by-side intermeshing rotors, as the means to solve the problem of torque compensation, normally countered in single–rotor helicopters by a tail rotor, fenestron, NOTAR, or vented blower exhaust. Flettner remained in the United States and became the chief designer of the Kaman company.[4] In this capacity, he designed numerous new helicopters that used the Flettner double rotor.
On 21 April 1953, the first prototype, referred to by the manufacturer as the K-225, made its maiden flight. It was later adopted by the United States Navy as the HTK-1, by which point it was outfitted with a single Lycoming O-435flat-six piston engine, producing 240hp (180kW). During 1954, for an experiment jointly conducted by Kaman and the U.S. Navy, a single HTK-1 was modified and flown with its piston engine having been replaced by a pair of Boeing T50-BO-2turbine engines totaling 380hp (280kW), becoming the world's first twin-turbine helicopter in the process.[5]
Subsequently, a much more powerful Pratt & Whitney R-1340 Waspradial piston engine, capable of producing 600hp (450kW), powered for the far heavier HOK-1, HUK-1, and H-43A versions for the United States Marines, U.S. Navy, and the United States Air Force, respectively. The U.S. Air Force also opted to procure two models that were powered by a single Lycoming T53turboshaft engine: the HH-43B with 860hp (640kW) and the HH-43F with 825hp (615kW).[6] The HH-43B variant established several world records for helicopters in its class during the early 1960s, including for rate of climb, altitude, and distance traveled.[7] The Huskie had a variety of tail and fin combinations over different variants, such a single tail with two or three fins or twin tail booms with four vertical fins.
Design
The twin intermeshed rotors of this designThe prominent exhaust tube the turbine powered versionHOK-1 with SS-11 (M22) missiles
The design had two main rotors, each with two blades, the blades were made primarily of wood and the two main rotors were linked by a transmission to keep them synced correctly.[8] The design used a variety of engines included a flat-six, radial engine, one gas turbine, and it was also tested with twin turbine engines. The rear of the aircraft had three main configurations three vertical fins on the end of single tail boom, three vertical fins on the end of twin tail booms, and finally 4 vertical fins on the end of twin tail booms along with an engine exhaust. The design usually had 4 wheels to land on, some had combined wheel and ski, and there was a version with twin floats.
Flight control on the HH-43 was primarily effected by a series of servo-flaps, or large tabs, that was located on the trailing edge of each rotor blade; the actuation of these flaps[how?] would cause the rotors to warp and thus cause the helicopter to either rise or descend as desired.[7] The rotor blades were composed of laminated wood; these restricted the aircraft's use in heavy rains as it could cause blade delamination.[9] There was no conventional tail rotor; its absence gave the rotorcraft a somewhat unusual look.[10] The contra-rotating twin rotors posed a particular hazard on the ground; crews were instructed to avoid approaching or departing the vehicle from the sides, but to instead advance or leave the vehicle from the front, as the blades would be at their highest at this position.[11] Warnings that reinforced this instruction were usually painted on the sides of the pylons which supported the rotor heads.
The B model had four vertical stabilizers at end of twin tail booms at the rear, but no tail rotor, as the two counter rotating main rotors balanced each other out. It had combination wheel and skids that aided in landing on soft ground.[12]
The interior of the T53 turbine powered HH-43 was divided in two somewhat cramped compartments, the cockpit at the front and an aft crew compartment, which were connected by a small opening that was too narrow for most personnel to pass through (the original radial piston powered versions lacked the aft compartment).[13] Dependent on the mission being performed, the aft compartment would be used to house firefighters, medics, mechanics, and/or rescued personnel; folding sidewall-mounted seats were provided for up to four personnel in this space, while the cockpit normally housed the pilot and co-pilot alone. In a typical configuration, a pair of clamshell doors would be fitted that could open up into the aft area of the rear compartment; in tropical conditions, these doors would often be removed to help cool the interior; in such a configuration, an aft net would be installed to prevent any personnel from falling out of the aircraft. No weapons mounts were officially approved, but some improvised arrangements did see the use of a Browning Automatic Rifle at the aft ramp position.[14]
On the exterior of the rotorcraft, a motorised hoist that was typically used for rescue missions was commonly fitted; control of the hoist was normally exercised from within the aft compartment, but the pilot could also directly control the hoist via the cyclic stick. For rescues at sea, a padded sling, nicknamed the 'horse collar', was fitted to the end of the hoist to aid in retrieval operations.[13] Due to unsatisfactory performance in the field, other devices were usually fitted, including the wire basket "Stokes litter" and a heavy "forest penetrator".[15] Also called a "Jungle penetrator", it had spring loaded arms and a seat, that could be ridden up or down from the helicopter with the hoist. A PJ could ride down and could help retrieve a downed airmen, and the rescue version had stretcher and medical kit inside.[16] The jungle penetrator had fold-out seats for up to three people.[12]
Operational history
USMC HOK-1 (later renamed OH-43D) carries drums, 1956A USAF Huskie aids a practice firefighting operation at Cam Ranh Bay Air Base, Vietnam in 1968HH-43B on a firefighting exercise in the 1960s. The helicopter had an especially strong downwash that could blow the smoke away from the firefightersFire suppression kit on display at the Museum of Aviation
The Huskie entered service in late 1958 with the Air Force. It was also adopted by the Navy and Marine Corp, but not the Army. It was used extensively in the Vietnam war, and was an important Search and rescue helicopter. It was also used to fight fires and for utility operations. The early radial engine-powered models gave way to turbine-powered ones. It was also sold on the civilian market, and at least one warbird models are in flying condition in the 21st century.
The HH-43 Huskie was procured by the U.S. Air Force; the first H-43As were delivered to the service in November 1958 while the first H-43Bs were accepted in June 1959.[7] The U.S. Air Force primarily procured the type to perform local base rescue operations and to fight aircraft fires. For the latter capacity, the H-43 was commonly outfitted with an airborne fire suppression kit that hung beneath it; this kit, which was developed at Wright-Patterson AFB, weighed only 1,000 pounds yet could output almost 700 gallons of fire-fighting foam. Huskies were usually capable of reaching crash sites before ground vehicles could, saving often-critical time in the rescue.[7] The helicopter had an especially strong down-wash that was useful in fighting fires.[8] During 1962, the USAF opted to change the H-43 designation to HH-43 to reflect the rotorcraft's role as a rescue vehicle. The HH-43F was the last model delivered to the U.S. Air Force, these differed from earlier models primarily by engine and rotor modifications that produced greater lift.[7]
The Huskie was deployed overseas during the Vietnam War; several detachments of the Pacific Air Rescue Center, the 33d, 36th, 37th, and 38th Air Rescue Squadrons, and the 40th Aerospace Rescue and Recovery Squadron operated the type. Personnel came to commonly refer to the aircraft by its call sign "Pedro". Early on, the rotorcraft's limited range proved to be a hindrance to operations; some crews resorted to an improvised additional fuel tank housed within the aft compartment, increasing fuel capacity by roughly 75 percent.[17] A Huskie performed the first combat medevac in March 1965, for an airmen downed in the Vietnamese Demilitarized Zone during Operation Rolling Thunder.[16] At the time the Huskies were the only rescue helicopters in service, other types, such as the Jolly Green Giant arrived later.[16]
During the conflict, the HH-43 flew more rescue missions than all other rotorcraft combined, largely due to its unique hovering capability; between 1966 and 1970, the type performed a total of 888 combat rescue, comprising 343 aircrew rescues and 545 non-aircrew rescues.[7] The type was also occasionally used as a firefighting vehicle in the theatre as well.[18] Noting the shortcomings of the HH-43, the procurement of newer aircraft, such as the Sikorsky CH-3C and HH-3E, was accelerated; their arrival in quantity supplanted the type and saw its being entirely replaced during the early 1970s.[19][20] However, the HH-43 did continue to serve in Southeast Asia until 1975, making it both the first and last rescue helicopter serving in that theatre.[16] (See also List of aircraft losses of the Vietnam War)
Pakistan procured three HH-43Bs in 1964 for Search and rescue and general support missions in its hot and multi-terrain environment. It equipped her airforce's No. 4 Squadron. During the 1965 Indo-Pakistani War, the Huskies were employed in logistic support missions for the Army, transporting artillery pieces and 31,000lb (14,000kg) of ammunition to inaccessible battlefields in the mountains of Kashmir.[21][22] On 8 July 1976, an H-43B from PAF Base Masroor was scrambled for a rescue mission in the Arabian Sea after receiving an SOS call from an Egyptian merchant ship "Latakia". All of the ship's crew were winched up safely before the ship sank.[23]
Iran received 20 HH-43Fs from 1965, with 17 going to the Imperial Iranian Army Aviation and the remaining three joining the Imperial Iranian Air Force.[24] The Iranian Army used its Huskies as utility helicopters, while the Iranian Air Force's helicopters were used for search and rescue duties.[25] The army's Huskies were later transferred to the air force, where they remained in use until being replaced by Bell 214 helicopters in 1978.[26] After the outbreak of the Iran-Iraq War in 1980, four HH-43s were reactivated by the Islamic Republic of Iran Air Force for use as air ambulances. They were used to transport casualties that had been airlifted to Tehran by Hercules transport aircraft to hospitals about Tehran for treatment. The four Huskies continued in use from 1983 to 1985, when they were retired following a fatal crash.[26]
Many retired Huskies were used in the logging industry until spares were difficult to get, then the price dropped and they were harder to keep in operation.[8] A HH-43 operating in the logging industry had a crash in 2006, with a failure of main gear box due to cracks.[27] The FAA said the helicopter gearbox had likely developed cracks from carrying heavy loads of logs.[27]
There is one known flying and restored Huskie by the 2020s, which is sometimes flown at the Olympia Air show.[28] There is not many spare parts available for the Huskie by this time, in particular the rotor blades.[8]
Variants
HH-43AHH-43B Huskie in museumOH-43D Huskie in 1960HH-43F (K-600)
An HTK was tested with twin Boeing 502 turboshafts in 1954, this was the first twin-turbine helicopter.
three-seat production version powered by a 240hp (180kW) Lycoming O-435-4 flat-six piston engine for the United States Navy,[31][32] later became TH-43E, 29 built
XHTK-1G
one example for evaluation by the United States Coast Guard
HTK-1K
one example for static tests as a drone
XHOK-1
prototype of United States Marine Corps version, two built
HOK-1
United States Marine Corps version powered by a 600hp (450kW) R-1340-48 Wasp radial piston engine; later became OH-43D, 81 built
In addition to those on static display, there was one known airworthy example at the Olympic Flight Museum by the 2020s.[41] While various HH-43s still exist, some models can be quite rare. For example, only of two of the 18 USAF HH-43A survived and neither is on display.[42]
A HH-43B on display at Hubschraubermuseum Bückeburg, Germany
58-1841 – HH-43F on static display at the Military Firefighter Heritage Display at Goodfellow Air Force Base in San Angelo, Texas. It is incorrectly painted with Air Force Serial Number 58-1481. This Huskie was a ground trainer (circa 1962–1976) at Sheppard Air Force Base, so it retained the square-tail empennage that was removed from almost all other Huskies after repeated rotor strikes in heavy winds. After being sold by the military, but before arriving at its current location, it was on display at the Pate Museum of Transportation in Cresson, Texas.[58]
The Kaman SH-2 Seasprite is a ship-based helicopter originally developed and produced by American manufacturer Kaman Aircraft Corporation. It has been typically used as a compact and fast-moving rotorcraft for utility and anti-submarine warfare (ASW) missions. Early on it was modest sized single-engined naval utility helicopter, and progressed to twin-engine ASW and SAR, and the latest model served well into the 21st century, with G model in active service in the 2020s with Egypt, New Zealand, Peru, and Poland.
The Westland Whirlwind helicopter was a British licence-built version of the U.S. Sikorsky S-55/H-19 Chickasaw. It primarily served with the Royal Navy's Fleet Air Arm in anti-submarine and search and rescue roles. It was also exported to other countries, and the Whirlwind was succeeded by the turbine powered Westland Wessex which was developed from the H-19/Whirlwind. The helicopter was made in many variants using a variety of radial (piston) and turbine engines.
Kaman Corporation is an American aerospace company, with headquarters in Bloomfield, Connecticut. It was founded in 1945 by Charles Kaman. During the first ten years the company operated exclusively as a designer and manufacturer of several helicopters that set world records and achieved many aviation firsts.
The Sikorsky H-19 Chickasaw is a multi-purpose piston-engined helicopter that was used by the United States Army and United States Air Force. It was also license-built by Westland Aircraft as the Westland Whirlwind in the United Kingdom. United States Navy and United States Coast Guard models were designated HO4S, while those of the U.S. Marine Corps were designated HRS. In 1962, the U.S. Navy, U.S. Coast Guard and U.S. Marine Corps versions were all redesignated as H-19s like their U.S. Army and U.S. Air Force counterparts.
The Piasecki H-21 Workhorse/Shawnee is an American helicopter, the fourth of a line of tandem rotor helicopters designed and built by Piasecki Helicopter. Commonly called "the flying banana", it was a multi-mission helicopter, capable of being fitted with wheels, skis or floats.
The Hiller YH-32 Hornet is an American ultralight helicopter built by Hiller Aircraft in the early 1950s. It was a small and unique design because it was powered by two Hiller 8RJ2B ramjet engines mounted on the rotor blade tips which weigh 13 lb (5.9 kg) each and deliver an equivalent of 45 hp (34 kW) for a total of 90 hp (67 kW). Versions of the HJ-1 Hornet were built for the United States Army and the United States Navy in the early 1950s.
The Bell 47 is a single-rotor single-engine light helicopter manufactured by Bell Helicopter. It was based on the third Bell 30 prototype, which was the company's first helicopter designed by Arthur M. Young. The 47 became the first helicopter certified for civilian use on 8 March 1946. The first civilian delivery was made on 31 December 1946 to Helicopter Air Transport. More than 5,600 Bell 47s were produced, including those under license by Agusta in Italy, Kawasaki Heavy Industries in Japan, and Westland Aircraft in the United Kingdom. The Bell 47J Ranger is a modified version with a fully enclosed cabin and tail boom.
The Sikorsky H-34 is an American piston-engined military utility helicopter originally designed by Sikorsky as an anti-submarine warfare (ASW) aircraft for the United States Navy. A development of the smaller Sikorsky H-19 Chickasaw (S-55), the H-34 was originally powered by a radial engine, but was later adapted to turbine power by the British licensee as the Westland Wessex and by Sikorsky as the S-58T. The H-34 was also produced under license in France by Sud Aviation.
The Sikorsky HH-52 Seaguard is an early amphibious helicopter designed and produced by American helicopter manufacturer Sikorsky Aircraft. It was the first of the company's amphibious rotorcraft to fly and the United States Coast Guard's first turbine-powered helicopter and first amphibious helicopter.
The Sikorsky R-4 is a two-seat helicopter that was 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 used by the United States Army Air Forces, the United States Navy, the United States Coast Guard and the United Kingdom's Royal Air Force and Royal Navy. In U.S. Navy and U.S. Coast Guard service, the helicopter was known as the Sikorsky HNS-1. In British service it was known as the Hoverfly.
The Flettner Fl 282 Kolibri (Hummingbird) is a single-seat intermeshing rotor helicopter, or synchropter, produced by Anton Flettner of Germany. According to Yves Le Bec, the Flettner Fl 282 was the world's first series production helicopter.
The Saunders-Roe Skeeter is a two-seat training and scout helicopter that was developed and produced by British manufacturer Saunders-Roe ("Saro") of Cowes and Southampton, in the United Kingdom.
An intermeshing-rotor helicopter is a helicopter with a set of two main rotors turning in opposite directions, with each rotor mast mounted with a slight angle to the other, in a transversely symmetrical manner, so that the blades intermesh without colliding. The arrangement allows the helicopter to function without a tail rotor, which saves power. However, neither rotor lifts directly vertically, which reduces efficiency per each rotor.
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of short take-off and landing (STOL) or short take-off and vertical landing (STOVL) aircraft cannot perform without a runway.
The Kaman K-MAX is a helicopter with intermeshing rotors (synchropter) designed and produced by the American manufacturer Kaman Aircraft.
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. The S-61R served in the United States Air Force as the CH-3C/E Sea King and the HH-3E Jolly Green Giant, and with the United States Coast Guard as the HH-3F, nicknamed "Pelican". This article covers several different variants of this type in different roles, one major difference compared to the S-61 was a rear ramp.
The Gyrodyne RON Rotorcycle was a tiny, single-seat helicopter designed under contract for the United States Navy. in the mid-1950s. It later was redesigned for a U.S. Marine Corps requirement for a small personal helicopter that would fulfill an array of roles, including observation, liaison, small unit tactical maneuvers, and which could be dropped to downed airmen behind enemy lines to facilitate their escape.
The Kellett XR-8 was a helicopter built in the United States during World War II. It was a two-seat machine intended to demonstrate the feasibility of a twin-rotor system and, while it accomplished this, it also demonstrated a number of problems that prevented further development of this particular design.
The Bell 47J Ranger is an American single-engine single-rotor light helicopter manufactured by Bell Helicopter. It was an executive variant of the highly successful Bell 47 and was the first helicopter to carry a United States president.
The Kaman K-225 is an American experimental helicopter developed by Kaman Aircraft. One example was modified to become the world's first gas turbine-powered helicopter.
↑ "Aircraft Listing"(PDF). Flying Leathernecks. Flying Leatherneck Historical Foundation. Archived from the original(PDF) on 4 March 2016. Retrieved 30 October 2016.
↑ "FAA REGISTRY [N4069R]". Federal Aviation Administration. U.S. Department of Transportation. Archived from the original on 31 October 2016. Retrieved 31 October 2016.
Chiles, James R. (2007). The God Machine: From Boomerangs to Black Hawks: The Story of the Helicopter. New York, US: Bantam Books. ISBN978-0-553-80447-8.
Francillon, René J. (1997). McDonnell Douglas Aircraft since 1920: Volume II. London, UK: Putnam. ISBN0-85177-827-5.
Frawley, Gerard (2003). The International Directory of Civil Aircraft, 2003-2004. Fyshwick, Canberra, Act, Australia: Aerospace Publications Pty Ltd. p.155. ISBN1-875671-58-7.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
