The Sikorsky HH-52 Seaguard (company designation S-62) was 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.
The USCG would procure 99 S-62s, which it initially designated as the HU2S-1G Seaguard, and later redesignated as the HH-52A Seaguard. It was primarily operated by the USCG for air-sea rescue missions. Various other operators opted to procure the S-62 for their own purposes, from airliners to utility transporters, and foreign air services. It was widely used into the 1980s, when many operators elected to replace the type with newer rotorcraft. The HH-52 was withdrawn from USCG service during 1989 in favor of nonamphibious rotorcraft, such as the Eurocopter HH-65 Dolphin, which rely solely on the use of a winch from a low hover to conduct rescue operations.
Development of the S-62 was launched by Sikorsky during the late 1950s; the initiative was initially pursued as an independent commercial venture.[1] In concept, the project combined the dynamic elements of the earlier Sikorsky S-55 with a boat hull-shaped fuselage and a single lightweight turboshaft engine.[1] This was a relatively ambitious design for the era, being the first of Sikorsky's amphibious helicopters.[2]
On 14 May 1958, the prototype S-62 performed its maiden flight; in doing so, it had beat its larger Sikorsky S-61 sibling into flight by almost a year.[3] This prototype was powered by a single General Electric T58-GE-6 turboshaft that had been derated from 1,050 hp to 670 hp, powering identical main and tail rotors to those of the S-55.
At Sikorsky's own expense, it funded a "fly before you buy" test program at the Naval Air Test Center in Patuxent River, Maryland; the company actively promoted the type to the United States Coast Guard (USCG) in particular.[1] The results of this test program was largely positive, confirming Sikorsky's performance claims and its suitability for the service. Accordingly, on 21 June 1962, Sikorsky was issued an initial production contract for the type.[1] On 9 January 1963, the first of 99 production helicopters was delivered to the USCG. On 17 January 1969, the final example were delivered by the company.[1]
Perhaps the most prominent feature of the S-62 is its boat hull fuselage, which was more compact, but otherwise similar to the preceding Sikorsky S-61 (adopted by the US Navy as the SH-3 Sea King). This fuselage is watertight, facilitating landings on water and snow alike, and furnished with two outrigger floats that help the rotorcraft resist both pitching and rolling motions while on the water's surface. These outrigger floats also accommodated the landing gear, which was retractable.[2] To maintain its position while on the water, it was able to deploy an anchor.[4]
Although the S-62 bore little visual resemblance to the Sikorsky S-55, it used many of the same components.[2] It was powered by a single General Electric T58-GE-8B turboshaft engine, capable to generating up to 1,250 hp (930 kW); it was a derated version of the T58-GE-10 powerplant used on the larger, twin-engined SH-3. The S-62 had sufficient power to carry up to 12 passengers, or six litters, along with a crew of three.[2]
One prominent early use of the S-62 was with the operator San Francisco and Oakland Helicopter Airlines, one of the first helicopter airlines to operate without a federal subsidy,[5] and the first to operate exclusively using turbine engine helicopters; the airline commenced passenger flights using a pair of two leased S-62s in June 1961, each of which being configured to carry up to 10 passengers.[6][7] On 21 December of that year, rival operator Los Angeles Airways performed the first scheduled service using an American turbine-powered helicopter via a leased S-62.[8] By June 1962, three S-62s were reportedly in operation for specialized transportation purposes, such as servicing offshore oil rigs in the Gulf of Mexico, with Petroleum Helicopters.[9] Other early civilian operators included Okanagan Helicopters, which used its S-62s to supply remote radar installations, and the Canadian Department of Transport, which had the type fly resupply missions to its lighthouses.[10]
HH-52A, in 1986
A large fleet of 99 S-62s was purchased by the US Navy's Bureau of Aeronautics on behalf of the USCG, who operated the type primarily for search and rescue missions. It was initially designated HU2S-1G Seaguard, but was redesignated as the HH-52A Seaguard in 1962. The HH-52 was commonly dispatched aboard the USCG's larger cutters and icebreakers. The turbine-powered helicopter could carry greater payloads and fly faster than many preceding aircraft, such as the H-19 (S-55). Being designed to be amphibious, the installation of additional flotation gear was not required for over-water flights, and rescues could be conducted by simply landing on the water. Water pickups were considered to be quicker than hoisting survivors up to the helicopter.[1]
Across its services life, the HH-52 fleet played an active role during various emergencies and other circumstances.[1] During the aftermath of Hurricane Betsey in 1965, the type rescued 1,200 people. The HH-52 was periodically used to provide logistical support in Antarctica.[1] One HH-52 was present for the foundering of the oil tanker Burmah Agate on 1 November 1979, facilitating in the rescue of personnel from the affected vessels.[4]
The HH-52 fleet was active for a total of 26 years, during which it reportedly was responsible for saving in excess of 15,000 people from various forms of life-threatening situations.[1] Having been eclipsed by newer rotorcraft, the final flight of a HH-52 took placed on 12 September 1989, after which the type was officially withdrawn from USCG service.[4][1] It was primarily replaced by the Eurocopter HH-65 Dolphin, a conventional nonamphibious helicopter.[11]
U.S. Coast Guard HH-52A floating in Seattle in 1979
S-62
Prototype. First flew on 14 May 1958.
S-62A
Amphibious transport helicopter, powered by a General Electric CT58-110-1 turboshaft engine, with accommodation for up to 11 passengers. The S-62A was the first production version.
S-62B
One S-62 was fitted with the main rotor system of the Sikorsky S-58.
HH-52A Seaguard 'USCG1355' at the National Museum of Naval Aviation in Pensacola, FloridaCockpit of HH-52A Seaguard 'USCG1355' at the National Museum of Naval Aviation in PensacolaAn HH-52 Seaguard on display at the Udvar-Hazy Center
While the type remains in service, a number of Seaguards are on display at museums around the world:
USCG 1423 – HH-52A cockpit section only on static display at the National Museum of Naval Aviation at Naval Air Station Pensacola in Pensacola, Florida.[37]
^"HH-52 Helicopter". Naval Air Station Wildwood Aviation Museum. NASW Aviation Museum. Archived from the original on 9 August 2017. Retrieved 2 June 2017.
Endres, Günter G. World Airline Fleets 1979. Hounslow, UK: Airline Publications and Sales Ltd., 1979. ISBN0-905117-53-0.
Leyes, Richard A. and William A. Fleming. The History of North American Small Gas Turbine Aircraft Engines. American Institute of Aeronautics and Astronautics, 2007. ISBN1-563473-32-1.
McGowen, Stanley S. Helicopters: An Illustrated History of Their Impact. ABC-CLIO, 2005. ISBN1-851094-68-7.
Taylor, John W. R.Jane's All The World's Aircraft 1969–70. London:Jane's Yearbooks, 1969.
Japan
Philippines
United States
Iceland
Qatar
Thailand
