Development and Qualification of the S-76C+ Helicopter with 30-Second/2-Minute OEI Power Ratings

The S-76C+ is the first U.S. manufactured helicopter to be certified in accordance with the FAA’s new 30-second/2-minute OEI power ratings, and the first Sikorsky helicopter to be FAA/CAA certified to fully harmonized FAR/JAR-29 performance criteria. This paper discusses the joint Sikorsky/Turbomeca development flight test effort commencing with the shipment of Sikorsky’s S-76C test aircraft to Turbomeca’s CGTM flight test subsidiary at Pau, France where it was converted into a “flying test bench” for Arriel 2S1 engine development. Concurrent with Turbomeca’s engine development effort, custom engine FADEC software was developed and refined, applying the lessons learned during previous FADEC development testing to optimize S-76C+/Arriel 2S1 engine operating characteristics. Unique engine integration and pilot training features were developed to accommodate the new 30-second/2-minute OEI power rating structure. Upon completion of development testing, the S-76C+ test aircraft returned to Sikorsky’s development flight center at West Palm Beach, Florida for low altitude, warm weather qualification testing, followed by cold weather testing at Fairbanks, Alaska, high altitude testing at Leadville, Colorado, and elevated helideck testing at a North Sea based oil drilling rig off the coast of Wick, Scotland.