42 U.S.C. § 7571 — Establishment of standards

(a) Study; proposed standards; hearings; issuance of regulations. (1) Within 90 days of December 31, 1970, the Administrator had to begin studying aircraft air pollutant emissions to determine (A) how much they affect air quality in air quality control regions across the country, and (B) whether it's technologically possible to control them. (2) (A) From time to time, the Administrator must propose emission standards for any class of aircraft engines whose emissions, in the Administrator's judgment, cause or contribute to air pollution that may reasonably be expected to endanger public health or welfare. (B)(i) The Administrator must consult the Federal Aviation Administration on aircraft engine emission standards. (ii) The Administrator cannot change these standards if doing so would significantly raise noise or hurt safety. (3) The Administrator must hold public hearings on proposed standards, held as much as practical in the air quality control regions most affected by aircraft emissions. Within 90 days after proposing the regulations, the Administrator must issue them, with whatever changes seem appropriate. These regulations can be revised over time. (b) Effective date of regulations. Any regulation under this section (or revision of one) takes effect after whatever period the Administrator — after consulting the Secretary of Transportation — finds necessary to let the needed technology be developed and applied, while considering the cost of compliance during that period. (c) Regulations which create hazards to aircraft safety. Any regulation in effect under this section on August 7, 1977, or proposed or issued afterward, or any amendment to one, does not apply to aircraft if the President disapproves it — after notice and a public hearing — based on a finding by the Secretary of Transportation that the regulation would create an aircraft safety hazard. That finding must include a reasonably specific explanation of its basis.