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The H-1 Upgrades Program is an Acquisition Category 1D Program executing an Engineering and Manufacturing Development contract with Bell Helicopter Textron Inc. The Upgrades Program will take the existing UH-1N and AH-1W helicopter airframes and provide a common 4-bladed rotor and drive system, a new main transmission, 4-bladed tail rotor, and many changes designed to bring the two airframes into as identical a configuration as possible. The aircraft will also receive integrated cockpits as a part of the modification. The program recently passed its Preliminary Design Review. This paper will discuss some of the program rationale and background information and focus on the advantages of the IPT process in general, and specifically as it relates to system safety.

The paper will present experimental results from two recent icing tests in the NASA Glenn Icing Research Tunnel (IRT). The first test, conducted in February 2009, was to evaluate the current recommended scaling methods for fixed wing on representative rotor airfoils at fixed angle of attack. For this test, scaling was based on the modified Ruff method with scale velocity determined by constant Weber number and water film Weber number. Models were un-swept NACA 0012 wing sections. The reference model had a chord of 91.4 cm and scale model had a chord of 35.6 cm. Reference tests were conducted with velocity of 100 kt (52 m/s), droplet medium volume diameter (MVD) 195 μm, and stagnation-point freezing fractions of 0.3 and 0.5 at angle of attack of 5° and 7°. It was shown that good ice shape scaling was achieved with constant Weber number for NACA 0012 airfoils with angle of attack up to 7°.