14 CFR § 21.8 - Approval of articles.

If an article is required to be approved under this chapter, it may be approved—

(a) Under a PMA;

(b) Under a TSO;

(c) In conjunction with type certification procedures for a product; or

(d) In any other manner approved by the FAA.

[Doc. No. FAA–2006–5877, Amdt. 21–92, 74 FR 53385, Oct. 16, 2009]