#### § 34.71 Non-volatile particulate matter (nvPM) test procedures.

For each Class TF, T3, or T8 engine manufactured after January 1, 2023, that has a rated output greater than 26.7 kN, the test procedures for measuring each required nvPM parameter are as follows:

(a) Measure the emissions of all nvPM parameters required in this part, as applicable.

(b) Collect data from at least three engine tests, with each test conducted at the reference LTO time/thrust combinations shown in [paragraph (h)](/on/2024-09-19/title-14/section-34.71#p-34.71(h)) of this section.

(c) For the engines referenced in [paragraph (b)](/on/2024-09-19/title-14/section-34.71#p-34.71(b)) of this section, all emissions certification tests may be conducted on one or more engines of the same type design.

(d) Use a test fuel that meets the specifications described in Appendix 4 of ICAO Annex 16, Volume II (incorporated by reference, see [§ 34.4](/on/2024-09-19/title-14/section-34.4)). The test fuel must not have any additive whose purpose is to suppress nvPM emissions.

(e)

(1) When conducting test measurements in accordance with [paragraphs (a)](/on/2024-09-19/title-14/section-34.71#p-34.71(a)) through [(c)](/on/2024-09-19/title-14/section-34.71#p-34.71(c)) of this section, use the equipment and procedures specified in Appendix 1, Appendix 4, Appendix 6, and Appendix 7 of ICAO Annex 16, Volume II (incorporated by reference, see [§ 34.4](/on/2024-09-19/title-14/section-34.4)), when demonstrating whether an engine meets the applicable nvPM limit specified in [§ 34.25 of this part](/on/2024-09-19/title-14/part-34/section-34.25).

(2) An applicant that seeks to use a procedure or equipment that differs from any specified in this part must request FAA approval in writing with supporting justification before the alternative procedure or equipment may be used to demonstrate compliance. The FAA will consult with the EPA on any such request. The FAA may approve the requested alternative for measuring nvPM, including testing and sampling methods, analytical techniques, and equipment specifications. Each request must meet one of the following conditions:

(i) The engine cannot be tested using a specified procedure; or

(ii) The alternative procedure is shown to be equivalent to, or more accurate or precise than, the specified procedure.

(f) Any engine accessory included in a type design that may reasonably be expected to influence either nvPM emissions or measurements must be installed on the engine before testing. The test engine must not extract shaft power or bleed service air to provide power to auxiliary gearbox-mounted components necessary to drive aircraft systems;

(g) For each percentage of rated output thrust level prescribed in [paragraph (h)](/on/2024-09-19/title-14/section-34.71#p-34.71(h)) of this section, a test engine must reach and maintain a steady operating condition before any nvPM emission measurement is made;

(h) The following landing and takeoff (LTO) cycles apply for nvPM emissions testing and for calculating weighted LTO values:

Table 1 to Paragraph (h)

| Mode | Class TF, T3, T8 | |
| --- | --- | --- |
| TIM (min) | % of rO |
| Taxi/idle | 26.0 | 7 |
| Takeoff | 0.7 | 100 |
| Climbout | 2.2 | 85 |
| Descent | NA | NA |
| Approach | 4.0 | 30 |

(i) An engine complies with an applicable limit if the test results show that the engine type certificate family's characteristic level does not exceed any limit for maximum nvPMMC, nvPMnum, and nvPMmass described in [§ 34.25](/on/2024-09-19/title-14/section-34.25).

(j) All measurements collected during engine tests required in [paragraph (b)](/on/2024-09-19/title-14/section-34.71#p-34.71(b)) of this section must be used in the calculation of nvPM. Before any calculations are made, the FAA must approve the exclusion of any measurements that the applicant seeks to exclude, including any justification for such exclusions.

(k) The system and procedure for sampling and measurement of gaseous emissions shall be as specified by Appendices 1, 4, 6, and 7 of ICAO Annex 16, Volume II (incorporated by reference, see [§ 34.4](/on/2024-09-19/title-14/section-34.4)).