14 C.F.R. § 35.16

The integrity of each propeller critical part identified by the safety analysis required by § 35.15 must be established by:

(a) A defined engineering process for ensuring the integrity of the propeller critical part throughout its service life,

(b) A defined manufacturing process that identifies the requirements to consistently produce the propeller critical part as required by the engineering process, and

(c) A defined service management process that identifies the continued airworthiness requirements of the propeller critical part as required by the engineering process.