14 CFR 34.25
§ 34.25 Non-volatile particulate emissions standards (nvPM).
United States · 14 CFR — Aeronautics and Space · Status: effective
Cite this
- Citation
- 14 CFR 34.25, § 34.25 Non-volatile particulate emissions standards (nvPM), United States, version 1 as recorded 2026-07-09, yourstate.us, https://yourstate.us/provision/55138
- Permanent ID
ys:prov:55138@1- SHA-256
9dc95cd36fc42a948a48e896398be894816f754f40450b62f9edbf9662b7cbd4
The hash is SHA-256 of this version's text, with every run of whitespace collapsed to a single space and the ends trimmed. The ID always leads back here, and checking it says whether the text you cited is still the current version.
Full text
The standards of this section apply to an aircraft engine of Class TF, T3, or T8 with a rated output greater than 26.7 kN that is manufactured after January 1, 2023. Where a maximum nvPMMC standard is expressed as a formula, calculate and round the standard to the nearest 1.0 µg/m 3. Where an nvPMmass standard is expressed as a formula, calculate and round the standard to three significant figures or to the nearest 0.1 mg/kN. Where an nvPMnum standard is expressed as a formula, calculate and round the standard to three significant figures. Engines comply with an applicable standard if the test results show that the engine type certificate family's characteristic level does not exceed the numerical level of the nvPM standard when tested as described in subpart H of this part.
(a) Except as provided in paragraph (b) or (c) of this section;
(1) The characteristic level for the maximum nvPMMC expressed in units of µg/m 3 must not exceed the following:
and
(2) The characteristic level for nvPM mass expressed in [mg/kN] and for nvPM number expressed in [particles/kN] must not exceed the following:
Table 1 to Paragraph (a)(2)
(b) For a change in type design by the type design holder, when the application for an amended type certificate is filed after January 1, 2023:
(1) If the engine qualifies as a derivative engine in accordance with § 34.48 of this part, no testing is required for the engine to use the same nvPM certificated parameters (nvPMmass, nvPMnum, and maximum nvPMMC) as the engine it is derived from; or
(2) If the engine does not qualify as a derivative engine in accordance with § 34.48 of this part, the applicant must demonstrate compliance with each requirement in paragraph (a) of this section.
(c) For issuance of an original type certificate when an application for type certification is filed after January 1, 2023, the applicant must demonstrate that the engine does not exceed:
(1) For maximum nvPMMC: as prescribed in paragraph (a)(1) of this section; and
(2) For the characteristic level for nvPMmass expressed in units of [mg/kN], and for nvPMnum expressed in units of [particles/kN], the following:
Table 2 to Paragraph (c)(2)
(d) For engines type certificated after January 1, 2023 and prior to May 24, 2024, compliance with this part must be demonstrated no later than August 22, 2024.
Legislative history
This is a federal regulation, adopted through agency rulemaking under the Administrative Procedure Act — not enacted by a recorded vote of Congress.