14 CFR §36.1583

1. (a)This section applies to propeller-driven, small airplanes that—
   1. (1)Are designed for “agricultural aircraft operations” (as defined in § 137.3 of this chapter, effective on January 1, 1966) or for dispensing fire fighting materials; and
   2. (2)Have not been shown to comply with the noise levels prescribed under appendix F of this part—
      1. (i)For which application is made for the original issue of a standard airworthiness certificate and that do not have any flight time before January 1, 1980; or
      2. (ii)For which application is made for an acoustical change approval, for airplanes which have a standard airworthiness certificate after the change in the type design, and that do not have any flight time in the changed configuration before January 1, 1980.
2. (b)For airplanes covered by this section an operating limitation reading as follows must be furnished in the manner prescribed in § 36.1581: