William G. Flannelly
United States of America
1931 - 1993
William G. Flannell joined Kaman Aerospace in 1957. In his 36 years at Kaman, he participated in the design, analysis, and tests of all of Kaman's helicopters from the HOK to the present K-MAX and he made significant contributions to these programs.
He also made outstanding contributions to the helicopter industry, particularly in anti-resonant theory. Bill held thirty patents. Two of his inventions - Gyroscopic Vibration Absorber, a tunable vibration absorber, and the Dynamic Anti-Resonant Vibration Absorber (DAVI) tuned to a specific frequency - proved deadly and was perfectly suited to helicopter application for vibration isolation. The late Dr. Irwin Vigness of the Naval Research Laboratory thought the DAVI to be the most significant contribution to vibration control since the development of the vibration absorber.
Bill was an expert in the theory of structural dynamics. This expertise led to the development of analytical testing, which utilizes mobility test data and analysis to provide the global parameters of a structure, i.e., mass damping, modes, and natural frequency. These analytical testing procedures led to system identification, a methodology which uses the global parameters of a structure and mobility data to yield the equations of motion of the structure without the use of theoretically derived equations.
Generalized force determination, also developed by Bill, is a method utilizing mobility data and the response of the vehicle in flight to determine the minimum forces required to duplicate the flight characteristics. This methodology is ideally suited for low and hi-cycle fatigue tests. Bill's most recent contributions are in the field of Holometrics, a technical procedure that determines loads occurring in the helicopter rotating system by monitoring fixed system parameters.
He received a BS degree from Rensselaer Polytechnic Institute in 1954. A member of the Society of Sigma Xi, he has served on the Dynamics Committee of the American Helicopter Society, as a referee for the Presidential Young Investigation Award of the National Science Foundation, as a reviewer for the Shock and Vibration Information Center of the Naval Research Laboratory, and on doctoral thesis committees at RPI. He has authored twenty professional papers and published several articles in engineering magazines. He was listed in the book "American Men and Women in Science" and was also listed in "Who's Who on the Eastern Shore."
William died on October 31, 1993, at Manchester Memorial Hospital after a long illness.
AHS Update: Vertiflite March/April 1994