SAE ARP4418A

Aircraft propulsion engine and APU manufacturers shall demonstrate that air provided to the aircraft cabin is of acceptable quality. This ARP provides the basic information required to perform an engine bleed air quality certification test. This document provides the recommended levels and describes the measurement procedures required for the quantification of gaseous and particulate contaminants, which may be present in aircraft engine bleed air.

Recommended techniques for engine sampling and sample transfer are given, together with specific analytical methodology, for each of the contaminants listed in Section 3. Recommendations are also made for an engine test format and for the allowance of ambient air quality on the measured engine contaminant concentration levels. The list and recommended limits of contaminants in Table 1 are considered appropriate for the certification and passenger safety requirements of both civil and military aircraft. If testing is performed on the aircraft, the operator should be aware that other sources of contamination may be present.