This article is about the civil versions of the Sikorsky S-61 models. For the military versions, see
SH-3 Sea King.
An S-61 helitanker uses a snorkel to refill its internal water tanks
The 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.1
Design and development
In September 1957, Sikorsky won a United States Navy development contract for an amphibious anti-submarine warfare (ASW) helicopter capable of detecting and attacking submarines.1 The XHSS-2 Sea King prototype flew on March 11, 1959. Production deliveries of the HSS-2 (later designated SH-3A) began in September 1961, with the initial production aircraft being powered by two 930kW (1250shp) General Electric T58-GE-8B turboshafts.
Sikorsky was quick to develop a commercial model of the Sea King.1 The S-61L first flew on November 2, 1961, and was 4ft 3in (1.27m) longer than the HSS-2 in order to carry a substantial payload of freight or passengers. Initial production S-61Ls were powered by two 1350shp (1005kW) GE CT58-140 turboshafts, the civil version of the T58. The S-61L features a modified landing gear without float stabilisers.
Los Angeles Airways was the first civil operator of the S-612 introducing them on March 1, 1962, for a purchased price of $650,000 each. 3
On August 7, 1962, the S-61N made its first flight.1 Otherwise identical to the S-61L, this version is optimized for overwater operations, particularly oil rig support, by retaining the SH-3's floats. Both the S-61L and S-61N were subsequently updated to Mk II standard with improvements including more powerful CT58-110 engines giving better hot and high performance, vibration damping and other detail refinements.
The Payloader, a stripped down version optimised for aerial crane work, was the third civil model of the S-61.1 The Payloader features the fixed undercarriage of the S-61L, but with an empty weight almost 2000lb (900kg) less than the standard S-61N.
A unique version is the S-61 Shortsky conversion of S-61Ls and Ns by Helipro International.1 The fuselage is shortened by 50in (1.6m) to increase single engine performance and external payload. The Shortsky conversion first flew in February 1996.
Variants
- S-61L
- Non-amphibious civil transport version. It can seat up to 30 passengers (13 Built).
- S-61L Mk II
- Improved version of the S-61L helicopter, equipped with cargo bins.
- S-61N
- Amphibious civil transport version.
- S-61N Mk II
- Improved version of the S-61N helicopter.
- S-61 Payloader
- Stripped down machine optimised for aerial crane work; features the fixed undercarriage of the S-61L, but with an empty weight almost 900kg (2000lb) less than the standard S-61N.
- S-61 Shortsky
- Shortened conversion of the S-61L and N, designed to increase single engine performance and external payload.
Operators
- Former operators are marked by italics
Greenland
Canada
United Kingdom
Netherlands
Pakistan
United States
Ireland
Notable accidents
N300Y, the S-61L prototype, departing from
Disneyland Heliport on a flight five years prior to its accident flight.
- On May 22, 1968, Los Angeles Airways Flight 841 crashed near Paramount, California, resulting in the loss of 23 lives. The accident aircraft, N303Y, serial number 61060, was a Sikorsky 61L en route to Los Angeles International Airport from the Disneyland Heliport in Anaheim, California.
- On August 14, 1968, Los Angeles Airways Flight 417 crashed in Compton, California, while en route to the Disneyland Heliport in Anaheim, California from Los Angeles International Airport, resulting in the loss of 21 lives. The accident aircraft, N300Y, serial number 61031, was the prototype of the Sikorsky S-61L.4
- On July 16, 1983, British Airways Helicopters' commercial S-61 G-BEON crashed in the southern Celtic Sea, in the Atlantic Ocean, while en route from Penzance to St Mary's, Isles of Scilly in thick fog. Only six of the 26 on board survived. It sparked a review of helicopter safety and was the worst civilian helicopter disaster in the UK until 1986.
- On August 5, 2008,two pilots and seven firefighters assigned to the Iron Complex fire in California's Shasta-Trinity National Forest, perished in a crash as they were taking off from a helispot in a Carson Helicopters Sikorsky S-61N helicopter (N612AZ). Of the 13 people reported to be on-board, one other pilot and three firefighters survived the crash. The four survivors were subsequently transported to hospitals with serious and some critical injuries. The cause of the incident is under investigation.5
Specifications (S-61N Mk II)
Data from International Directiory of Civil Aircraft1
General characteristics
- Crew: 2 pilots
- Capacity: up to 30 passengers
- Length: 58 ft 11 in (17.96 m)
- Rotor diameter: 62 ft (18.9 m)
- Height: 17 ft 6 in (5.32 m)
- Disc area: 3,019 ft² (280.6 m²)
- Empty weight: 12,336 lb (5,595 kg)
- Loaded weight: lb (kg)
- Max takeoff weight: 19,000 lb (8,620 kg)
- Powerplant: 2× General Electric CT58-140 turboshafts, 1,500 shp (1,120 kW) each
Performance
See also
Related development
References
- ^ a b c d e f g h Frawley, Gerard: The International Directiory of Civil Aircraft, 2003-2004, page 194. Aerospace Publications Pty Ltd, 2003. ISBN 1-875671-58-7
- ^ Sikorsky S-61N
- ^ "The Self-Supporting Helicopter" Time Magazine December 26, 1960
- ^ Aircraft Accident Report. Los Angeles Airways, Inc. S-61L Helicopter, N300Y, Compton, California, Adopted: August 27, 1969
- ^ "USFA Fatality Notice", United States Fire Administration (2008-08-05). Retrieved on 11 August 2008.
External links
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Greenland
Canada
United Kingdom
Netherlands
Pakistan
United States
Ireland
