Evaluation of the Sierra Engineering Company Lightweight Helmet
Final rept. May 1976-Aug 1977
SIERRA ENGINEERING CO SIERRA MADRE CA
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This report covers the advanced development of a lightweight helmet LWH which has recently been evaluated as a candidate for reducing the stress and strain on the neck of aircrew-members exposed to sustained high levels of positive acceleration G sub B. During Phase I, Sierra provided ten helmets for testing six LWHs for the contractor-performed testing of impact and penetration resistance, acoustic attenuation, and windtunnelantilift characteristics and four LWHs for USAF-conducted assessments relevant to fit, maintainability, retentionpressure breathing, fixed visual fields, altitude, thermal, acceleration, voice communications effectiveness, chemical-defense equipment, and cockpit compatibility. The HGU-26P was used as the basis for comparison. During these evaluations, problems were noted in the areas of mask retention, which in turn caused difficulties with pressure breathing and mask slippage during Gz and fit, which led to visorspectacle interference and visormask incompatibility. During Phase II Sierra provided twenty helmets for flight testing at Nellis AFB in the AIMVALACEVAL program. These helmets were flown in both F-5 and F-15 aircraft. During these evaluations, problems were noted in the areas of liner comfort, chinstrap comfort, and integration with full-length bayonets. Although the helmet was not found acceptable from a comfortfitting standpoint, the louvered visor cover and flattened side portions of the shell, which reduced aerodynamic lift, were considered a major advance in helmet design. This was in addition to the lower profile, improved peripheral vision, and excellent stability under high G.
- Protective Equipment