14 CFR § 252.9 - Ventilation systems.

---
identifier: "/us/cfr/t14/s252.9"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 252.9 - Ventilation systems."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "252.9"
section_name: "Ventilation systems."
chapter_name: "OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS)"
subchapter_number: "A"
subchapter_name: "ECONOMIC REGULATIONS"
part_number: "252"
part_name: "SMOKING ABOARD AIRCRAFT"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "Pub. L. 101-164; 49 U.S.C. 40102, 40109, 40113, 41701, 41702, 41706 as amended by section 708 of Pub. L. 106-181 and section 401 of Pub. L. 112-95, 41711, and 46301."
regulatory_source: "Docket No. DOT-OST-2000-7473, 65 FR 36775, June 9, 2000, unless otherwise noted."
cfr_part: "252"
---


# 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.