Definition
A United States federal law, enacted in 1970, that requires federal agencies — including the FAA — to assess the environmental effects of their proposed actions before making decisions. Under NEPA, projects such as new airport construction, runway extensions, changes to airspace or flight procedures, and certain federally funded aviation projects must go through an environmental review, typically resulting in either an Environmental Assessment (EA) or a more detailed Environmental Impact Statement (EIS).
Plain English
A federal law that says government agencies must study the environmental impact of what they plan to do before they do it. In aviation, this is why new airport projects, runway changes, or new flight procedures often go through an environmental review.
Context Anchor
Seen in FAA acronym lists and in discussions about airport development, airspace changes, runway projects, or other FAA approvals that may need an environmental review.
Derivation
From 'national' (covering the whole country), 'environmental' (relating to the surroundings — air, water, land, communities), and 'policy act' (a law setting government policy). The name signals what it does: a nationwide law setting how the federal government must consider environmental effects.
Why Pilots Care
NEPA is the reason new airport projects, instrument procedures, and airspace modifications can take years to approve. Pilots involved in airport development, flight school expansion, or community discussions about aviation noise will encounter NEPA reviews directly.
Example Sentence 1
The proposed runway extension was delayed while the airport completed the environmental review required under NEPA.
Example Sentence 2
NEPA documentation sometimes affects where new flight procedures can be published near protected lands.