14 CFR §21.185

1. (a)Aircraft manufactured under a production certificate or type certificate. An applicant for a restricted category airworthiness certificate for an aircraft type certificated in the restricted category, that was not previously type certificated in any other category, must comply with § 21.183(a) or (b), as applicable. A used aircraft must conform to its type certificate and be in a condition for safe operation.
2. (b)Other aircraft. An applicant for an airworthiness certificate in the restricted category is entitled to an airworthiness certificate if—
   1. (1)The aircraft is type certificated for a special purpose operation in the restricted category;
   2. (2)The aircraft was—
      1. (i)Manufactured in accordance with the requirements of, and accepted for use by, the U.S. Armed Forces and has a service history with the U.S. Armed Forces acceptable to the FAA; or
      2. (ii)Previously type certificated in another category; and
   3. (3)The aircraft has been inspected by the FAA and found by him to be in a good state of preservation and repair and in a condition for safe operation.
3. (c)Import aircraft. An applicant for the original issue of a special airworthiness certificate for a restricted category import aircraft is entitled to that certificate if—
   1. (1)The aircraft is type-certificated in accordance with § 21.25 or § 21.29 and produced under the authority of another State of Manufacture;
   2. (2)The State of Manufacture certifies, in accordance with the export provisions of an agreement with the United States for import of that aircraft that the aircraft conforms to the type design and is in condition for safe operation; and
   3. (3)The FAA finds that the aircraft conforms to the type design and is in condition for safe operation.
4. (d)Noise requirements. For propeller-driven small airplanes (except airplanes designed for “agricultural aircraft operations,” as defined in § 137.3 of this chapter, as effective on January 1, 1966, or for dispensing fire fighting materials) that have not had any flight time before the applicable date specified in Part 36 of this chapter, and notwithstanding the other provisions of this section, no original restricted category airworthiness certificate is issued under this section unless the FAA finds that the type design complies with the applicable noise requirements of Part 36 of this chapter in addition to the applicable airworthiness requirements of this section. For import airplanes, compliance with this paragraph is shown if the country in which the airplane was manufactured certifies, and the FAA finds, that the applicable requirements of Part 36 of this chapter (or the applicable airplane noise requirements of the country in which the airplane was manufactured and any other requirements the FAA may prescribe to provide noise levels no greater than those provided by compliance with the applicable requirements of Part 36 of this chapter) and paragraph (c) of this section are complied with.