14 CFR §161.201

1. (a)This subpart applies to:
   1. (1)An airport imposing a noise or access restriction on the operation of Stage 2 aircraft, but not Stage 3 aircraft, proposed after October 1, 1990.
   2. (2)An airport imposing an amendment to a Stage 2 restriction, if the amendment is proposed after October 1, 1990, and reduces or limits Stage 2 aircraft operations (compared to the restriction that it amends) or affects aircraft safety.
2. (b)This subpart does not apply to an airport imposing a Stage 2 restriction specifically exempted in § 161.7 or a Stage 2 restriction contained in an agreement as long as the restriction is not enforced against aircraft operators that are not parties to the agreement.