14 CFR 252.9 - Ventilation systems.
Air carriers shall prohibit smoking whenever the ventilation system is not fully functioning. Fully functioning for this purpose means operating so as to provide the level and quality of ventilation specified and designed by the manufacturer for the number of persons currently in the passenger compartment.
Title 14 published on 2015-01-01.
No entries appear in the Federal Register after this date, for 14 CFR Part 252.