14 CFR §147.19
Each certificated aviation maintenance technician school must:
- (a)Provide qualified instructors to teach in a manner that ensures positive educational outcomes are achieved;
- (b)Ensure instructors either—
- (1)Hold a mechanic certificate with one or more appropriate ratings; or
- (2)If they do not hold a mechanic certificate, are otherwise specifically qualified to teach their assigned content; and
- (c)Ensure the student-to-instructor ratio does not exceed 25:1 for any shop class.