On December 23, the U.S. Environmental Protection Agency (EPA) issued its final rule on greenhouse gas (GHG) emission standards for large turbine airplanes flown by commercial and business aviation operators. This action does not require aircraft or engine manufacturers to reduce their products’ actual emissions but rather aligns U.S. standards with the carbon dioxide (CO2) emissions standards set in 2017 by the International Civil Aviation Organization (ICAO).

Comments submitted to the EPA when the rule was in its proposed stage last summer were split mainly into two voices: those from the aviation manufacturing industry and its trade associations that were generally satisfied with the proposal, and those from environmental groups that were dismayed that the rule did not require any actual reduction in GHG emissions.

Representing the viewpoint of many environmental organizations that commented on the proposal, the Environmental Defense Fund said, by the EPA's own admission, the rule does nothing to reduce emissions from aircraft. “EPA’s promulgation of a final rule on aircraft GHG emissions recognizes that it’s essential to look at the entire aircraft, not just the engine, since the structure, operation, and fuel characteristics are all important determinants of aviation pollution. However, this do-nothing rule is totally inadequate in light of the climate crisis."

The comments from most of the aircraft and engine manufacturers were summed up by the Aerospace Industries Association's response to the new standards. "With this final rule, the EPA has demonstrated America’s commitment to global action against climate change and ensured U.S. aircraft will meet the same standards as our competitors across the world," said the AIA. "Improving aircraft efficiency is a crucial part of the aviation industry’s plans to reduce CO2 emissions, and we look forward to working with the FAA to incorporate this standard into its aircraft certification requirements.”

Even independent of the ICAO standards, nearly all airplanes produced by U.S. manufacturers will meet the ICAO in-production standards in 2028. The EPA expects that existing in-production aircraft that are non-compliant will either be modified and re-certificated as compliant, go out of production before the Jan. 1, 2028 compliance date, or their manufacturer will seek exemptions from the GHG standard.

While the EPA admits it is not projecting emission reductions associated with these GHG regulations, it said the rules create a baseline for aircraft GHG emissions. In addition, any modifications made to airplanes that result in an increase in GHG emissions will trigger a requirement to certify to the in-production regulation beginning Jan. 1, 2023.

The regulations apply to subsonic jet airplanes having mtows between 5,701 kg and 60,000 kg (12,568 and 132,277 pounds, respectively) and 19 seats or less with an original FAA type certificate application made on or after Jan. 1, 2023. It also applies to turboprops with an mtow exceeding 8,618 kg (18,999 pounds) and an original FAA type certificate submitted on or after Jan. 1, 2020.

The FAA is working on rulemaking that incorporates the EPA emissions standards and provides for FAA enforcement of those standards, including testing requirements and exemption procedures that the FAA will apply when certifying new airplanes. The agency anticipates publishing a notice of proposed rulemaking next year for public comment on the implementing rule.