Technical Paper
Certification of the Sikorsky S-92A® Helicopter Ice Protection System: Meteorological Aspects of Tanker Tests and Natural Icing Flights
2007-09-24
2007-01-3329
Sikorsky Aircraft Corporation flew the S-92A® helicopter into natural and tanker artificial icing conditions as part of the certification program for the rotor ice protection system (RIPS). Icing tanker tests were conducted during the late winter of 2004, and natural icing flights were made during the spring of 2004, winter of 2004-05, and early fall of 2005. One goal of the natural icing flight program was to obtain water-dominated icing encounters at temperatures between -15 and -23.33°C. Past studies have shown that mixed-phase icing is often found in this temperature range, and that most icing occurs at temperatures warmer than -15°C. Tanker tests were conducted at specific temperatures at altitudes below about 3 km (10,000 ft), and under prolonged weather conditions meeting visual flight rules (VFR). This represents a challenging combination of conditions to find within a small radius of operation from a given airport.