CFR›Title 14›Chapter I›Part 34›Subpart D ContainsSections 34.30–34.31CorpusDaily eCFRDisplayed edition2026-04-27Last updated2026-04-27 Subpart D—Exhaust Emissions (In-use Aircraft Gas Turbine Engines) Sections 34.30 § 34.30 Applicability. 34.31 § 34.31 Standards for exhaust emissions. Previous C Subpart C—Exhaust Emissions (New Aircraft Gas Turbine Engines) Next E Subpart E—Certification Provisions