Foil: 5 Panel: 4 Column: 2 Line: 91

Wall of Honor Level:
Air and Space Friend

Honored by:
Cynthia Bowden

Dr. Hammond has 38 years of experience in the Aerospace arena: 15 years in electronics and missiles industry and 23 years in government Civil Service and Military. His government experience includes aircraft depot level maintenance, aircraft vulnerability, warhead kill mechanism performance, wind tunnel testing of fixed wing and rotary wing aircraft and advanced development programs for Army helicopters. His industrial experience involves design, development, and production of fire control systems and tactical missiles. A highlight of Dr. Hammond's career has been the receipt of the American Helicopter Society's Howard Hughes Award in 1983 in recognition of the successful development and flight test of the Higher Harmonic Control (HHC) demonstrated by the feasibility of a concept to reduce the vibration levels in a helicopter's airframe by as much as 80 percent during a series of flight tests in 1982. The program began when Dr. Hammond formulated a plant to experimentally establish the feasibility of vibration reduction through he application of higher harmonic control of a helicopter. Through a series of tests at the Langley Transonic Dynamics wind tunnel, he demonstrated that small amplitude control oscillations are effective in reducing vibratory shear and moments on a multi-bladed rotor. With these encouraging results, Dr. Hammond developed the algorithm necessary to provide closed-loop control of a higher harmonic system, which has been successfully flight tested. The HHC system is an electronic, computer-controlled suppression system which senses and cancels vibrations in a helicopter airframe through high frequency feathering of the rotor blades.