(a) This subpart applies to an airport operator's noise or access restriction on the operation of Stage 3 aircraft that is implemented pursuant to an agreement between an airport operator and all aircraft operators affected by the proposed restriction that are serving or will be serving such airport within 180 days of the date of the proposed restriction.(b) For purposes of this subpart, an agreement shall be in writing and signed by: (1) The airport operator;(2) Those aircraft operators currently operating at the airport who would be affected by the noise or access restriction; and(3) All new entrants that have submitted the information required under § 161.105(a) of this part.(c) This subpart does not apply to restrictions exempted in § 161.7 of this part.(d) This subpart does not limit the right of an airport operator to enter into an agreement with one or more aircraft operators that restricts the operation of Stage 2 or Stage 3 aircraft as long as the restriction is not enforced against aircraft operators that are not party to the agreement. Such an agreement is not covered by this subpart except that an aircraft operator may apply for sanctions pursuant to subpart F of this part for restrictions the airport operator seeks to impose other than those in the agreement.