14 CFR § 5.93
Safety communication
July 13, 2020
The certificate holder must develop and maintain means for communicating safety information that, at a minimum:
(a) Ensures that employees are aware of the SMS policies, processes, and tools that are relevant to their responsibilities.
(b) Conveys hazard information relevant to the employee's responsibilities.
(c) Explains why safety actions have been taken.
(d) Explains why safety procedures are introduced or changed.