Compare the fixed costs, variable cost, and performance of Sikorsky S-76B to over 500 jets, turboprops, helicopters and piston aircraft, with accurate data from Conklin & de Decker.
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, among others, 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 This was superseded by the S 76A Mark II in 1982 and modification kits were made available for all earlier S 76 A. In 1985 the S 76 B was certificated. The S 76B uses more powerful Pratt & Whitney engines, has an upgraded transmission and a higher take off gross weight. The primary focus of this model was to increase hot and high performance and to increase payload.
The S 76B 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 76 B are the Pratt & Whitney Canada PT6-36A. 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 76 B program was launched in 1983 and first flight of the prototype occurred in 1984. Certification to the standards of FAR 29 was obtained in 1985. Category A certification was obtained in late 1987. The increased gross weight was approved in 1988. Deliveries started in 1985 and production ceased in 1997. During this time, a total of about 85 S 76B were delivered.
Pratt & Whitney Canada PT6B-36 2