FAA Federal Aviation Regulations (FARS, 14 CFR)

The factor of safety prescribed in §23.303 must be multiplied by the highest pertinent special factors of safety prescribed in §§23.621 through 23.625 for each part of the structure whose strength is --

(a) Uncertain;

(b) Likely to deteriorate in service before normal replacement; or

(c) Subject to appreciable variability because of uncertainties in manufacturing processes or inspection methods.

[Amdt. 23-7, 34 FR 13091, Aug. 13, 1969]