STUDY OF THE BREATHING EFFECT ON THE H-21 HELICOPTER
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1961
- Accession Number
- AD0259151
Entities
People
- William B. Peck
- William S. Nutley
Organizations
- Boeing Rotorcraft Systems