Measurement of rotor noise levels and evaluation of porous blade tips on a CH-47A helicopter
By: prepared by the Boeing Company, Vertol Division.
Contributors: Sternfeld, H.; Army Aviation Materiel Laboratories (U.S.); Boeing Vertol Company
Publisher: U.S. Army Aviation Materiel Laboratories
Published: 1969
Place of publication: Fort Eustis, Va
Number of pages: 100
Subjects: Helicopters; Rotary wings; Rotor acoustics
Notes: Final report D8-0439B.

Includes bibliographical references: p. 63.