On July 22, 2020, the Environmental Protection Agency (“EPA”) proposed a rule establishing Greenhouse Gas (“GHG”) emissions standards for larger civilian jet and turboprop aircraft. Civilian aircraft account for ten percent of U.S. transportation-related, and about three percent of U.S. total, GHG emissions. Most of those aircraft emissions are from the larger aircraft covered by the rule. The standards do not apply to many small business jets, smaller turboprop aircraft, piston-engine aircraft, helicopters, or military aircraft.
The proposed rules are required as a result of EPA’s 2016 finding that GHG emissions from certain classes of aircraft engines endanger public health and welfare and to maintain consistency with standards set by the International Civil Aviation Organization (“ICAO”)1 in 2017. The Federal Aviation Administration (“FAA”) participates in the ICAO to establish international standards, and EPA serves as an advisor to the FAA in that process. EPA rules must be at least as stringent as the ICAO environmental standards to ensure global acceptance of FAA airworthiness certification of aircraft.
In the proposed rulemaking, EPA concludes that adopting a rule consistent with the ICAO standard satisfies the GHG rulemaking required by the 2016 endangerment finding. Only two GHGs are emitted in measurable quantities by the regulated aircraft engines: CO2 and N2O. CO2 accounts for 99 percent of aircraft GHG emissions. Similar to automobile emission standards, EPA is proposing to regulate energy efficiency rather than directly regulate CO2 or N2O emissions.
Consistent with the ICAO standard, the proposed rule adopts a whole-plane efficiency metric (rather than relying on engine efficiency) that considers the aircraft’s weight, propulsion, and aerodynamic characteristics. The fuel efficiency standard for each aircraft, referred to as a “fuel efficiency metric value,” is calculated using equations in the rule for specific categories of covered aircraft. The fuel efficiency metric value is calculated based on the maximum takeoff mass of the aircraft.
The other two variables in the efficiency calculation are: (1) the specific air range (“SAR”), which is a measure of fuel efficiency based on how far an airplane can fly on a single unit of fuel at the optimum cruise altitude and speed, and (2) the reference geometric factor (“RFG”), which is a calculation related to the aircraft passenger area dimensions. Using these factors and calculations, the standards account for and vary based on: aerodynamics, airplane weight, and engine propulsion technologies. The aerodynamics and engine propulsion technology will affect the SAR but are not a direct component of the calculation. These airplane performance characteristics affect the overall GHG emissions. As a result, unlike automobile fuel efficiency standards, the applicable standard for a particular aircraft is the result of a calculation that is provided in the rules.
The standards will apply to new aircraft designs submitted to the FAA after January 1, 2020 or January 1, 2023, depending on the size of the aircraft (the later deadline will apply to smaller planes, generally having 19 or fewer passenger seats). For aircraft designs that are already in production, the proposed rule would apply GHG standards beginning in 2028.
The rule requires manufacturers of airplanes subject to the rule to report annually information on the number of aircraft manufactured, information needed to calculate the fuel efficiency factors and limited additional information. If the information related to fuel efficiency does not change from one year to the next, the report need only include the number of aircraft of each type that were produced in the reporting year.
EPA predicts that the new rule will not result in emission reductions because manufacturers are already working to comply with the ICAO standards. EPA predicts only a small cost for the rule because it adds only an annual reporting requirement to the ICAO standards.
Comments on the proposed rule will be due 60 days after it is published in the Federal Register.
1 The ICAO is an international agency created in 1944 to manage the administration and governance of the Convention on International Civil Aviation (“Chicago Convention”). The ICAO works with Member States and industry groups to reach consensus on safety and environmental standards and policies applicable to the commercial aviation industry.
