Environmental control system (ECS) design approach for collective nuclear, biological, and chemical (NBC) protection in military aircraft: A review

This comprehensive review paper delves into Environmental Control System (ECS) design strategies tailored for collective Nuclear, Biological, and Chemical (NBC) protection in military aircraft, exploring key elements such as hardening, air-tight construction, and filtering within the framework of open-loop or closed-loop ECS configurations. Initially, the paper elucidates the NBC protection requirements stipulated in commonly applied regulations such as MIL-HDBK-516C, DEFSTAN, and EMACC, highlighting the imperative for ventilation air to be devoid of contaminants, as mandated by these regulations. Subsequently, the paper delineates the strategic framework for NBC defense in the military aerospace industry, emphasizing the principles of avoidance, protection, and decontamination. A comparative analysis between individual and collective protection strategies underscores the comprehensiveness of the latter, prompting a recommendation for ECS design approaches grounded in the principles of collective protection, namely hardening, air-tight construction, and filtering. Furthermore, the paper provides insights into the configurations of open-loop and partial closed-loop ECS, elucidating their architectures for NBC protection. A comparative evaluation of these configurations enables the identification of pertinent parameters crucial for informed selection. In conclusion, the paper posits that the partial closed-loop ECS configuration exhibits greater promise in delivering enhanced NBC protection compared to the open-loop configuration, particularly in military aircraft applications operating in NBC environments.