(a) The applicant must determine a special factor of safety for each critical design value for each part, article, or assembly for which that critical design value is uncertain, and for each part, article, or assembly that is—

1. (1) Likely to deteriorate in service before normal replacement; or
2. (2) Subject to appreciable variability because of uncertainties in manufacturing processes or inspection methods.

(b) The applicant must determine a special factor of safety using quality controls and specifications that account for each—

1. (1) Type of application;
2. (2) Inspection method;
3. (3) Structural test requirement;
4. (4) Sampling percentage; and
5. (5) Process and material control.