Vertiflite May/June 2021

his contributions, especially in integrating modern engine controls with helicopter responses. As the industry was transforming from limited-authority flight control systems to more advanced full-authority, fly-by-wire systems, Howlett provided leadership to the group that performed the control law design to take advantage of these new capabilities. Howlett’s most significant contribution, however, is undoubtedly his role as chief architect of Sikorsky’s blade- element flight dynamics simulation model known as GenHel (for “General Helicopter Dynamics Simulation Model”). He started that effort early in his career and is largely responsible for the development and maturity of the analysis detail that it includes. GenHel was a major advancement in rotorcraft flight simulation fidelity, which had been based on tip-path- plane models until that time. As digital computer power advanced, he continued to expand the physics that GenHel simulated. With increased computation power, the GenHel model ran in real-time, providing for a high-fidelity piloted simulation. Howlett’s continued efforts to improve simulation fidelity helped reduce the risk in design and helped reduce helicopter development time. Largely because of his efforts, the GenHel program is regarded by those at NASA Ames and within military research groups as an industry standard. Howlett continued that role as chief architect while managing the Handling Qualities and Control Law section until he retired. During his time at Sikorsky, he also managed to complete a Master of Business Administration (MBA) degree at New Haven University in 1981. Howlett was a visionary, recognizing the importance of many emerging technology advances in handling qualities criteria, system identification and flight control design to the new family of full-authority, fly-by-wire helicopters. Howlett also found time to mentor and teach many of the engineers that worked with and for him at Sikorsky. Howlett was a strong proponent of research collaborations, giving his young engineers opportunities to learn these new technologies and benefit from the interactions with colleagues outside of Sikorsky. In 2011, Howlett was recognized as a VFS Technical Fellow for making notable and outstanding technical contributions to the vertical flight community and advancing the interests of vertical flight. He was a long-time associate editor for the Society’s Journal of the AHS. Throughout his career he gained the respect not only of those within Sikorsky, but also of those in the company’s customer base, and his peers in industry and academia. Outside of work, Howlett enjoyed travelling the world with his wife Brenda and spending time with his children and grandchildren. He was an avid alpine skier and gardener, and coached soccer for the local town soccer program for 45 years.

Aerospace Engineering (AerE) at Iowa State University College of Engineering passed away March 19. A highly regarded researcher, he was responsible for unique contributions to rotorcraft, wind energy systems and computational fluid dynamics (CFD). During his time at Iowa State, Rajagopalan graduated 37 PhD and MS students, and taught numerous undergraduate

and graduate-level courses. He was a

dedicated teacher of aerospace engineering and shared his knowledge in a wide range of subject

matter, which included aerodynamics, gas dynamics, CFD, aircraft performance, flight dynamics and wind energy. He and his students have made significant and wide-ranging contributions to the field of CFD. Rajagopalan joined the Iowa State faculty in 1985 as an assistant professor and was promoted to associate professor in 1991 and professor in 2001. Prior to this, he was a lecturer, teaching fellow and research assistant at West Virginia University, where he received his PhD in aerospace engineering in 1984. He had received an MS in aerospace engineering from the Indian Institute of Science in 1978, a BS in aeronautical engineering from the Madras Institute of Technology in 1976 and a BS in mathematics from Madras University in 1973. He has been credited with numerous research citations, more than 70 research publications, 18 journal articles, and more than 50 conference papers at events around the world. He was also a principal investigator, co-principal investigator or investigator on more than 30 grant- supported research projects. Rajagopalan was a VFS lifetime member and Gold Circle member, which recognizes longtime members of the Society, which he joined in 1985; he received the Alfred Gessow Best Paper Award at Forum 61 in 2005. He was an AIAA Associate Fellow and a technical consultant for numerous corporate interests and a reviewer of archival journals for many publications.

May / June 2021

Anyone wishing to make a donation to the VFS Vertical Flight Foundation (VFF) scholarship fund in the memory of these or other past VFS members can go to www.vtol.org/VFF .

R. Ganesh Rajagopalan Professor, Iowa State University

Professor R. Ganesh Rajagopalan of the Department of

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