Section 33.15 - MaterialsThe suitability and durability of materials used in the engine must-
(a) Be established on the basis of experience or tests; and(b) Conform to approved specifications (such as industry or military specifications) that ensure their having the strength and other properties assumed in the design data.Amdt. 33-8, 42 FR 15047, Mar. 17, 1977, as amended by Amdt. 33-10, 49 FR 6850, Feb. 23, 1984 Secs. 313(a), 601, and 603, 72 Stat. 759, 775, 49 U.S.C. 1354(a) , 1421 , and 1423 ; sec. 6(c) , 49 U.S.C. 1655(c)