VOLUME 11, NO. 1     MAY 1997

Helicopter pioneer looks to the past and future

At the podium last spring to deliver the American Helicopter Society's prestigious Alexander A. Nikolsky Lecture in Washington, D.C., was Dave Jenney '53, a 40-year veteran of the rotary wing aircraft industry and editor in chief of the Journal of the American Helicopter Society. Jenney retired from Sikorsky Aircraft in 1993 as director of Comanche engineering. (Comanche is the nickname of the RAH-66, the Army's first stealth helicopter, currently in flight testing.)

Jenney insists it was just a lucky guess that brought him into this field, a hunch that helicopters would turn out to be a mechanical engineer's dream in terms of complexity and number of moving parts. "A rotor is so marvelously complicated," says Jenney. "I never guessed that 40 years later there would still be such complex problems to solve."

When Jenney entered the field in the 1950s, helicopter performance theory involved a linearized set of equations that could be solved pretty rapidly with a slide rule or desk calculator. "To simplify the calculations, we had to pretend that the rotor blades were rigid and the air currents were constant, even though we knew they weren't," he notes. At United Aircraft, Jenney began analyzing aerodynamics with a brand new IBM-701 - one of the first mainframe computers - which took up an entire air-conditioned room.

In recent years, tools such as parallel processors, real-time computer simulations, and CAD/CAM drawing capabilities have revolutionized the design process. But when it comes to analyzing the movement of air around the rotor and the effects of its chopping motion on the air currents, "the detail required to adequately model the wake and the blades is still a challenge to today's fastest computers," Jenney claims.

His address to the AHS, titled "Helicopter Technology: A Look Back and Forward," recalls Jenney's early days in the field, when the first helicopters were being used in Korea, mostly to airlift wounded soldiers (the basis of a very popular and long-running TV series, he notes). Next, the choppers' value in troop transport was exploited. During the Vietnam War guns were mounted on "Hueys," and missiles were added in the Persian Gulf War.

Modern helicopters are faster, quieter, smoother and safer than earlier "birds," thanks to the development of ultralight composites and alloys - and the perseverance of engineers like Jenney. The main thrust of current research is to bring down the cost of production and maintenance for military and civilian uses.

Although he is not licensed to fly, Jenney has gone up with pilots to test out new developments. He is more of a waterman, sailing his 16-foot Herreshoff out of Mattapoisett, Mass., where he and his wife, Janet, built their dream house. Jenney also travels by foot: he has jogged in 28 states and several countries, and has run nearly 20 marathons, including several shots at New York and Boston. When he takes to the air, it is for business travel or the genteel pleasure of choral tours throughout Scandinavia and in Vienna and other European cities.

Although Jenney was elated at the award, composing a lecture for the AHS annual meeting in the nation's capital was a daunting challenge. "Most of the previous winners were people I know and have admired," he says. "It's great to be in that company, but my predecessors had set a high standard and used up a lot of good material!" The text of his address is set for publication in the next issue of the AHS Journal.

Joan Killough-Miller

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