The U.S. Environmental Protection Agency (EPA) has issued a notice of proposed rulemaking to adopt particulate matter emission standards and test procedures to replace the existing smoke standard on large subsonic jet airplanes. The proposal also includes applying a smoke number standard for smaller turbine aircraft.
These proposed standards would be applicable to aircraft engines with a maximum thrust available for takeoff greater than 26.7 kilonewtons (6,000 pounds). The standards would apply to both new type design and in-production engines starting on Jan. 1, 2023.
Standards for in-production airplanes would have different emission limits than would the standards for new type designs, and those limits would depend on the rated output of the engines. The smoke number standards would apply to engines less than or equal to 26.7 kilonewtons. Comments on this proposal are due by April 4, 2022.
This proposal is separate from the recently adopted EPA regulation that established carbon dioxide (CO2) emissions standards on large jets and turboprops. The action does not require aircraft or engine manufacturers to reduce their actual emissions but rather aligns U.S. standards with CO2 emissions standards set by the International Civil Aviation Organization in 2017 and revised in 2020.