The
Sikorsky S-76 Spirit is an
American multi-purpose medium-size commercial
helicopter. The S-76 is powered by two
turboshafts which combine to drive the main and tail rotors, each with four blades. The S-76
landing gear is retractable.
Development
The development of the machine began with Sikorsky in the middle of the 1970s. Target group were companies, which looked for a medium business helicopter, as well as the oil drilling industry. Sikorsky's development experiences from the
UH-60 Black Hawk served as the basis for the
S-74 (later renamed
S-76 Spirit in honor of the
US Bicentennial). which was able to transport 2 pilots and 12 passengers, received first two
Allison 250 C30 turboshafts with 478
kW each. The prototype completed its first flight on 13 March 1977.
The S-76A was the first production variant. The type achieved 1982 several class records within the range climbing achievement, maximum speed and ceiling. Several airlines operate the S-76A on scheduled services including Helijet Airways of Vancouver, British Columbia, Canada.
After the S-76A, the S-76 Mk II (1982), the S-76B in the year 1987 with a top speed of 155 knots at sea level. Over 500 S-76s had been delivered by early 2001.
Until December 2005 the S-76C+ was in production. It is equipped with Turboméca Arriel 2S1 engines with FADEC and an
EFIS suite from Honeywell. The tail rotor could be made quieter by modification. For comfort, increased active noise and vibration dampers are used. The main rotor is manufactured from composite materials.
Since 3 January 2006 the certified S-76 C++ has the more efficient
Turboméca Arriel 2S2, an intake
air filter, an improved and quieter
transmission as well as changes of detail at the interior equipment and electronics. There were 92 orders for this model as of January 2006.
In 2009 the S-76D is currently under development and will be powered by 1,050 shp PW210S engines driving
composite material rotors and will incorporate active vibration control. A prototype made its first flight on 7 February 2009;
type certification is expected in 2010 and deliveries are anticipated later that year. Three prototypes will be used in the certification program. One aircraft will be used to obtain certification of an optional electric rotor ice-protection system. Performance will be substantially improved with the added power, but initial certification will retain the same gross weight (11,700 pounds) and maximum cruise speed (155 knots). The rotor rpm will be self adjusting in flight. The higher rpm setting for takeoff and landing and a lower rpm setting for cruise for improved range.
Variants
Civil
- S-76A : Original production version, powered by two 485-kW (650-shp) Rolls-Royce (Allison) 250-C30 turboshaft engines. Large number modified to S-76A+. 284 manufactured.
- S-76A Utility : Utility transport version, equipped with sliding doors and a strengthened floor.
- S-76A+ : Unsold S-76s were fitted with two Turbomeca Arriel 1S turboshaft engines. 17 manufactured.
- S-76A++ : S-76 helicopters fitted with two Turbomeca Arriel 1S1 turboshaft engines.
- S-76A Mk II : Improved all-weather transport version, fitted with more powerful engines, and other detail improvements.
- S-76C : Powered by two 539-kW (981-shp) Turboméca Arriel 1S1 turboshaft engines. 43 manufactured.
- S-76C+ : Uprated version, fitted with improved Arriel 2S1 turboshafts with FADEC. 35 manufactured.
- S-76C++ : Turboméca Arriel 2S2
- S-76D : Proposed version.
Military
- AUH-76 : Armed utility transport version, developed from the S-76 Mk. II.
- H-76B : Military version of the S-76B.
- H-76N : Planned naval version of 1984, not implemented.
Experimental derivatives
Sikorsky S-76 SHADOW
A S-76B prototype helicopter at 1991 Paris Air Show
: The Advanced Composite Airframe Program (ACAP) was an all-composite Sikorsky early LHX proof of concept aircraft. It mated a new
composite airframe with S-76 engines, rotors and powertrain components.
Sikorsky S-76 SHADOW : Boeing-Sikorsky MANPRINT study. The original concept of the LHX program was to produce a one-man helicopter that could do more than a two-man aircraft. The Sikorsky (S-76) Helicopter Advance Demonstrator of Operators Workload (SHADOW) had a single-pilot advanced cockpit grafted to its nose. The purpose was to study the MANPRINT or human engineering interface between the pilot and the cockpit controls and displays. The cockpit was the prototype of a single-pilot cockpit designed for use on the prototype
RAH-66 Comanche armed reconnaissance helicopter. The cockpit was designed so sensors would feed data to the pilot through helmet mounted displays. The MANPRINT study determined that single-pilot operation of the Comanche was unsafe, and would result in pilot overload. As result of this study, the Comanche was designed to be operated by a crew of two.
Operators
The S-76 is in use around the world with airlines, corporations, hospital, government operators and, notably, the
British Royal Family. The world's largest civilian fleet (79) of Sikorsky S-76 helicopters is operated by
CHC Helicopter Corporation.
Civil
- Ornge — 11 aircraft, to be phased out over two years from late 2010.
- Presidential fleet, 1 aircraft.
- Bristow In UK and Global, operating 53 S-76A, A+, A++, C+ and C++.
Military Operators
: (
UAE)
- Saudi Interior Ministry ordered 15 units in November 2007.
Incidents
Specifications (Sikorsky S-76C++)
A pair of
Helijet's Sikorsky S-76s at Vancouver Harbour
See also
