适航条款CCAR25.831(g)的符合性分析

Analysis for Complying With CCAR 25.831(g)

对于任何型号的民用飞机,直接验证适航条款CCAR25.831(g)都是非常困难的,甚至是不可能的,因为在某些低纬度地区环境湿度大于该条款的要求值。然而,FAA认可的MSHWG报告指出,通过验证与之安全等级相当的规则,该条款可以被间接验证。本文以MSHWG报告为指导,采用热应力计算分析,引用工作环境的国标规定和人体忍耐极限试验结果,验证了某支线客机对适航条款CCAR25.831(g)的符合性。

It＇ s difficult or impossible to comply with under the assumption of loss of all conditioned airflow for flight following failure, including descent and landing. It has been speculated that the fixed humidity level of 27 mBar appears to be a reasonable limit for altitude conditions around 10,000 feet. Unfortunately this humidity level is often exceeded at lower altitudes at and near sea level for airport ambient conditions. The MSHWG Final Report on FAR/JAR 25. 831 （g） , dated July 31,2003 proposed action is to harmonize on a new, performance-based regulation for failure conditions not shown to be extremely improbable. The objective of this regulation is to preserve a tolerable environment by limiting the metabolic and environmental heat loads to passengers and crew during exposures to a potential heat stress event. Relative to the current CCAR 25. 831 （ g）, and considering the inapplicability of its humidity requirements, the proposed regulation does not reduce the current level of safety. A thermal analysis of Regional Jets based upon computer modeling with validation is demonstrated, the GB/T 4200-2008 report re- garding work environment, and the human tolerance experimental results in high temperature and high humidity conditions are quoted to validate the ECS complying with CCAR 25. 831 （g） according to the new regulation in MSHWG report.