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Regulatory Brief - General Aviation and Greenhouse Gas EmissionRegulatory Brief - General Aviation and Greenhouse Gas Emission

Regulatory Brief

General Aviation and Greenhouse Gas Emission

The Issue

On Wednesday, July 30, 2008 the Environmental Protection Agency (EPA) issued an advanced notice of proposed rulemaking (ANPR) titled “Regulating Greenhouse Gas Emissions under the Clean Air Act.” This notice seeks ways to regulate greenhouse gas (GHG) emissions from many sources, including aircraft, under the Clean Air Act (CAA).

The EPA’s ANPR followed a Supreme Court ruling that compels the EPA to regulate greenhouse gases. The ANPR describes current sources of greenhouse gases emissions, including aviation.


Greenhouse gases trap heat in the atmosphere and can occur naturally in the environment and as a byproduct of other activities, like flying. Carbon dioxide is a greenhouse gas that results from burning fossil fuels, such as avgas or jet fuel.

General aviation is estimated to contribute less than one percent of all GHG emissions. Piston powered general aviation aircraft contribute an even smaller amount; slightly more than one-tenth of one percent (0.13 percent) of total GHG emissions. Recent technological advancements such as full authority digital engine control (FADEC) and the use of composite materials in airframe construction are decreasing emissions even further.

In November 2008, AOPA filed formal comments in response to the EPA’s notice concerning greenhouse gas emissions, pointing out that piston powered aircraft account for approximately one-tenth of 1 percent of total emissions. AOPA added that the figure could fall further as technological changes make general aviation increasingly environmentally friendly.

Why It’s Important

While the potential impact of greenhouse gas regulation is not yet known, EPA efforts to regulate greenhouse gas emissions could affect general aviation. Potential requirements to install pollution controls on general aviation aircraft could have a negative effect on the cost-sensitive general aviation community. Any other potential greenhouse gas emission mitigation factors, such as changes to how general aviation aircraft are operated would need to be carefully considered against the effects on aviation safety and the cost burden to the industry.

AOPA’s involvement in this issue is critical. While the EPA notice will not cause any immediate changes to general aviation aircraft or general aviation operations, the issue of emissions is expected to be an area of interest for the new congress.

AOPA’s Position

In its formal comments, AOPA told the EPA that imposing new regulations, equipment requirements, or operational changes on general aviation would be difficult to justify since general aviation is not a significant source of greenhouse gas emissions.

The ultimate authority over aviation in the U.S. is the Federal Aviation Administration. The FAA’s in-depth approval process for any change to aircraft is designed to ensure aviation safety and protect the lives of pilots and passengers. Retrofitting the existing general aviation fleet with pollution control devices would require the approval of the FAA, significant aircraft “down time” and disruption to the industry. EPA should carefully consider any changes to the general aviation industry given the industry’s minimal contribution to GHG emissions. Any proposed change should be fully coordinated and considered to ensure aviation safety is not compromised and the industry is not financially burdened.