§29.831 Ventilation

(a) Each passenger and crew com partment must be ventilated, and each crew com partment must have enough fresh air (but not less than 0.3 m3 (10 cu ft) per m inute per crew m ember) to let crew m embers perform their duties without undue discom fort or fatigue. (b) Crew and passenger com partment air m ust be free from harm ful or hazardous concentrations of gases or vapours. (c) The concentration of carbon m onoxide may not exceed one part in 20 000 parts of air during forward flight. If the concentration exceeds this value under other conditions, there m ust be suitable operating restrictions. (d) There m ust be m eans to ensure compliance with sub-paragraphs (b) and (c) under any reasonably probable failure of any ventilating, heating, or other system or equipment.