49 C.F.R. § 212.211

(a) The apprentice S&TC inspector must be enrolled in a program of training prescribed by the Associate Administrator leading to qualification as a S&TC inspector. The apprentice inspector may not participate in the investigative and surveillance activities, except as an assistant to a qualified State or FRA inspector while accompanying that qualified inspector.

(b) Prior to being enrolled in the program the apprentice inspector shall demonstrate:

(1) Working knowledge of basic electricity and the ability to use electrical test equipment in direct current and alternating current circuits; and

(2) A basic knowledge of S&TC inspection and maintenance methods and procedures.