The KUH-1 Surion is a twin-engine utility helicopter designed and developed jointly by Korea Aerospace Industries (KAI) and Airbus Helicopters primarily for the Republic of Korea Army (ROKA). Following customer requirements, KAI launched a program aimed at the military qualification of the KUH-1 for flight in icing conditions following tailored airworthiness certification criteria based on 14 CFR Part 29 and DEF STAN 00-970. The Netherlands Aerospace Centre (NLR) became involved in the program on the eve of the first icing flight test campaign performed in the winter of 2015/2016. NLR has supported all subsequent test activities and the finding of compliance in close collaboration with KAI and certain suppliers. The test activities performed include 1) component-level development and qualification icing wind tunnel testing at Cox & Co in Long Island, NY, 2) icing qualification testing of the engine air intake ice protection system at Rail Tec Arsenal (RTA) in Vienna, Austria, 3) artificial icing flight testing using the US Army Helicopter Icing Spray System (HISS), and 4) natural icing flight testing of the complete aircraft in the state of Michigan, USA. Following the extensive test activities, the KUH-1 was granted icing qualification by the Korean military airworthiness authorities in June of 2018. This paper provides an overview of the KUH-1 icing certification program, followed by a more detailed accounting of the most recent icing wind tunnel and flight test activities as outlined above, and a description of the ice protection system design for the engine air intake, the upper wire cutter and the main rotor system.
