Accession Number : AD0736347

Title :   Ground Test Evaluation of the Sikorsky Active Transmission Isolation System.

Descriptive Note : Final technical rept. 1 Jul 69-31 Oct 70,

Corporate Author : UNITED AIRCRAFT CORP STRATFORD CONN SIKORSKY AIRCRAFT DIV

Personal Author(s) : VON Hardenberg,Paul W. ; Saltanis,Paul B.

Report Date : SEP 1971

Pagination or Media Count : 125

Abstract : Active isolation of a full-scale CH-53A helicopter fuselage was successfully demonstrated during hangar shake tests. Overall reductions of approximately 70 percent in fuselage response to main rotor 6p excitations were achieved, while sensitivity to 1p in-plane excitation was increased by only 13 percent. These isolation levels were achieved with a design constrained by the geometry of the CH-53A fuselage. Analytical studies indicate that further reductions in vibratory response could be achieved if fuselage and isolation system design were integrated. (Author)

Descriptors :   (*FUSELAGES, *VIBRATION ISOLATORS), (*HELICOPTER ENGINES, VIBRATION), PERFORMANCE(ENGINEERING), HELICOPTER ROTORS, RESONANT FREQUENCY, STABILITY, TEST METHODS

Subject Categories : Helicopters
      Machinery and Tools

Distribution Statement : APPROVED FOR PUBLIC RELEASE