Sikorsky S-61 / HH-3A Sea King

Sikorsky Aircraft Corp.

First Flight March 11, 1959

Two seats

Acquisition Source: National Museum of Naval Aviation Loan

The S-61/ H3, developed from the U.S. Navy HSS-2 Sea King antisubmarine helicopter, was designed to fulfill a 1957 U.S. Navy requirement for an antisubmarine helicop­ter. Originally designated the HSS‑2 ‑ which was changed in 1962 to SH‑3 ‑ the Sea King entered U.S. Navy service in 1961.A relatively heavy helicopter for its time, the H‑3 had a large fuel capacity giving it high endurance for antisubmarine warfare or long range for rescue missions.

The SH‑3A served as the basis for a variety of other Sikorsky military and commercial models.The VH‑3A was built for U.S. Army and Marine Corps use as presidential heli­copters.

An extensively revised fuselage from the original Sikorsky S‑61A and B models identifies the S‑61 R which was sold to the Air Force and Coast Guard as a search and rescue (HH‑3E/F) and utility‑cargo helicopter (CH‑3C/E).

 U.S. Air Force variant was used extensively during the Vietnam War to rescue downed American flyers deep within North Vietnam.

The SH‑3A broke a number of speed records shortly after its service introduction. In Decem­ber 1961 it set records for 3, 100, 500 and 1,000 kilometers at 199, 182.8, 179.5 and 179.3 mph, respectively. In February 1962 it became the first helicopter to break the 200‑mph barrier by registering 210.6 mph over a 19‑kilometer course. The current world's records exceed these only marginally. A USAF HH‑3E made the first nonstop trans‑Atlantic helicopter flight.

The early S‑61A and B models have a boat‑type hull of metal semi‑monocoque construction and a folding tailboom to facilitate stowage. The S‑61R variants have a pod‑and‑boom, non‑watertight fuselage that is longer but narrower than the earlier Sea King versions, and which has a hydraulically operated rear ramp. All versions share the same five‑bladed main rotor and five‑bladed tail rotor system except that the blades on the S‑61R series do not fold. The S‑61A and B have retractable twin main and non‑retractable single tail wheel landing gear, while the S‑61 R has a fully retractable tricycle undercarriage.

Sikorsky built more than 1,100 S-61s in different models and this model also was built under license by Westland in Great Britain as Sea King and Commando, in Italy by Agusta as the AS-61 and in Japan by Mitsubishi.

According to the book "United States Naval Aviation 1910‑1970,” The Museum aircraft, BuNo. 151556 was the next to last of a series of 36 HSS‑2 helicopters (BUNO. 151522‑BuNo ‑ 151557) purchased from Sikorsky by the Navy ‑ Purchases after that were referred to specifically either SH‑3A or SH‑3D. No nameplate or contract number has been found to date which will help in the identification of the date of acquisition. According to Apostollo's "Illustrated Encyclopaedia of Helicopters", p. 85, twelve SH‑3As (possibly 12 of the 36 mentioned above) were converted to HH‑3As for battlefield use. No date was given. Vertiflite, Vol. 16, No. 3, March 1970 reports "HH‑3A Undergoing Navy Trials" firepower trials at Martha's Vineyard, MA with subsequent testing at NATC, Pax River, MD. The article further stated that conversion kits from SH‑3A to HH-3A were to be shipped to Quonset Point, RI for depot installation. It is assumed that the conversions were made subsequent to March 1970.

The cockpit of this aircraft has been treated to make it night vision goggle (NVG) compatible for GenII goggles. It is reasonable to assume that NVG compatibility was not part of the 1970 conversion kit.

Aircraft Specifications

Fuselage Length: 
54 ft. 9 in
Maximum Speed: 
267 mph
Height: 
16 ft. 10 in
Empty Weight: 
12,450 lbs.
Gross Weight: 
20,500 lbs.
Engine: 
2 1250 shp T58 GE 8B