Accession Number:

AD0259151

Title:

STUDY OF THE BREATHING EFFECT ON THE H-21 HELICOPTER

Descriptive Note:

Corporate Author:

BOEING CO MORTON PA VERTOL DIV

Personal Author(s):

Report Date:

1961-12-01

Pagination or Media Count:

1.0

Abstract:

An investigation was made of blast effects of a recoilless rifle fired from positions immediately beneath the H-21 helicopter to determine the feasibility of in-flight firing of the XM-29 weapon. The 3 sections of the study are identified as follows 1 airframe static stress analysis, 2 airframe dynamic analysis, and 3 rotor system investigation. Static stress analysis techniques were applied by isolating the critical instant of the dynamic blast loading time history and calculating the associated internal stress in fuselage frames. The most efficient reinforcements were found to be aluminum alloy angles and plate gussets riveted to existing structure six fuselage frames at an estimated weight cost of 10 lb per aircraft. Dynamic analysis methods were also applied to the fuselage frame. A quantitative appraisal was made of the capabilities of both the H21 wood rotor blade and metal blade in withstanding crushing action of the blast pressure. It is considered on the basis of this comparison that the wood blade is marginal and the metal blade probably adequate for withstanding the blast pressure. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE