Sec. 23.831 - Ventilation.
(a) Each passenger and crew compartment
must be suitably ventilated. Carbon monoxide concentration may not exceed
one part in 20,000 parts of air.
(b) For pressurized airplanes, the
ventilating air in the flightcrew and passenger compartments must be free
of harmful or hazardous concentrations of gases and vapors in normal
operations and in the event of reasonably probable failures or
malfunctioning of the ventilating, heating, pressurization, or other
systems and equipment. If accumulation of hazardous quantities of smoke in
the cockpit area is reasonably probable, smoke evacuation must be readily
accomplished starting with full pressurization and without depressurizing
beyond safe limits.
[Doc. No. 4080, 29 FR 17955, Dec. 18, 1964; 30
FR 258, Jan. 9, 1965, as amended by Amdt. 23-34, 52 FR 1831, Jan. 15,
1987; Amdt. 23-42, 56 FR 354, Jan. 3, 1991]