Sikorsky
In the early 1970’s it became clear that there was a demand for a medium twin-engine turbine helicopter for the offshore and corporate market. Sikorsky launched a series of design studies that resulted in a decision to launch the S-76 in 1975. The design that resulted and the decision to proceed with production made it Sikorsky’s first helicopter made from scratch for the civilian market, without major components based on a military design. The other major innovation was that it represented Sikorsky’s first extensive application of composites for the dynamic system and the fuselage. The original version of this helicopter was the S-76A (also referred to as the S-76 Spirit – a name that did not last). This was superseded by the S-76A Mark II in 1982 and modification kits were made available for all earlier S-76A. In 1985 the S-76B was certificated. The S-76B, which was in production until 1997, focused on increasing hot and high performance and to increase payload. In 1991 the S-76C was introduced. This helicopter, which uses Turbomeca engines, was intended as a direct replacement for the S-76A. In 1996, the S- 76C was replaced by the S-76C+ and in 2005 the S-76C+ was replaced by the S-76C++. This helicopter has significantly more horsepower and thus has much improved hot and high performance. As a consequence it is now the only S-76 model in production.
The S-76C++ uses a four-bladed fully articulated main rotor head with single elastomeric bearings. Dual bifilar vibration absorbers, mounted above the rotor head are used to decrease vibration levels. The engines used on the S-76C++ are the Turbomeca 2S2 with FADEC. A four-bladed tail rotor provides directional control. Both the main rotor blades and the tail rotor blades have a titanium main spar with a Nomex honeycomb airfoil shape and fiberglass outer cover. The fuselage provides two compartments. The pilot compartment seats two and the passenger cabin seats up to 12. The fuselage contains extensive Kevlar and honeycomb components. The passenger cabin is available in three basic configurations. One is a 5-place corporate interior with 2 comfortable seats facing aft and a three- place bench facing forward. The second is a 12 seat utility configuration. This has three forward facing rows with 4 seats each. The third configuration is for EMS operators. This configuration puts two stretchers and four medical attendants in the cabin.
The S-76C++ received its certification in 2006 and is currently in production. Certification is to the standards of FAR 29 with IFR and Category A capability.
