The US Environmental Protection Agency (EPA) proposed greenhouse gas (GHG) emissions standards for airplanes used in commercial aviation and large business jets. This proposed action would align US standards with the international CO₂ emissions standards adopted by the International Civil Aviation Organization (ICAO) in 2017, making domestically manufactured aircraft competitive in the global marketplace.

The new international Airplane CO₂ Emission Standards adopted by ICAO in 2017 are prescribed in ICAO Annex 16, Volume III titled, Aeroplane CO₂ Emissions.

The proposed EPA standards would address subsonic jet aircraft with a maximum takeoff mass (MTOM) greater than 5,700 kilograms and subsonic propeller-driven airplanes (e.g., turboprops) with a MTOM greater than 8,618 kilograms. Examples include larger business jets such as the Cessna Citation CJ3+, the larger commercial jet aircraft (such as the Boeing 777 and the Boeing 787) and larger civil turboprop airplanes such as the ATR 72 and the Viking Q400. These are same types of airplanes covered by the international aircraft CO₂ standard.

Aircraft covered by the proposed rule account for 10% of all US transportation greenhouse gas (GHG) emissions and 3% of total US GHG emissions.

The implementation process provides significant lead-time to designers and manufacturers of aircraft covered by the standards. The proposed GHG standards would apply to new type design airplanes on or after 1 January 2020 and to in-production airplanes on or after 1 January 2028. They would not apply to already manufactured airplanes that are currently in-use.

The EPA is proposing to adopt the ICAO CO₂ metric, which measures fuel efficiency, for demonstrating compliance with the GHG emission standards. This metric is a mathematical function that incorporates the specific air range (SAR) of an airplane/engine combination (a traditional measure of airplane cruise performance in units of kilometer/kilogram of fuel) and the reference geometric factor (RGF), a measure of fuselage size.

Proposed In-Production Rule

To measure airplane fuel efficiency, the EPA is proposing to adopt the ICAO test procedures whereby the airplane/engine SAR value is measured at three specific operating test points, and a composite of those results is used in the metric to determine compliance with the proposed GHG standards.

After EPA promulgates the final rule with the standards, FAA will complete a subsequent rulemaking to enforce these standards. At that point, FAA could begin to certify airplanes of US manufacturers. This process will take time, EPA said, and it is critical that EPA complete this part of the process so that the U.S. standards are in place well in advance of 2028, when the ICAO standards go into effect for in-production airplanes.

Under the Clean Air Act, in 2016 EPA found that emissions of GHGs from engines used in certain aircraft causes, or contributes to, air pollution which may reasonably be anticipated to endanger public health or welfare. These findings triggered a requirement for EPA to promulgate standards addressing GHG emissions from the engines of affected aircraft. The new action begins the process of following through on that requirement.

The ICAO standards were developed with input from EPA, the Federal Aviation Administration (FAA), and US and international aviation industries. Typically, three out of four aircraft manufactured in the US are sold overseas. EPA said that these standards will help ensure consistent standards across the world, and—most importantly—allow US-manufactured planes, such as commercial and large passenger jets, to continue to compete in the global marketplace.