Each safety belt must be equipped with a metal to metal latching device.
14 C.F.R. §27.1413
Secs. 313, 314, and 601 through 610 of the Federal Aviation Act of 1958 (49 U.S.C. 1354 , 1355 , and 1421 through 1430 ) and sec. 6(c), Dept. of Transportation Act (49 U.S.C. 1655(c)