14 CFR §21.115

1. (a)Each applicant for a supplemental type certificate must show that the altered product meets applicable requirements specified in § 21.101 and—
   1. (1)In the case of an acoustical change described in § 21.93(b), show compliance with the applicable noise requirements of part 36 of this chapter;
   2. (2)In the case of an emissions change described in § 21.93(c), show compliance with the applicable fuel venting and exhaust emissions requirements of part 34 of this chapter; and
   3. (3)In the case of a fuel efficiency change described in § 21.93(d), show compliance with the applicable fuel efficiency requirements of part 38 of this chapter.
2. (b)Each applicant for a supplemental type certificate must meet §§ 21.33 and 21.53 with respect to each change in the type design.