49 CFR 220.311 - Railroad operating employees in deadhead status.
(a) Notwithstanding any other restrictions in this subpart, a railroad operating employee who is in deadhead status and not inside the cab of a controlling locomotive may use an electronic device only if the employee is not using the device in such a way that interferes with any railroad operating employee's personal safety or performance of safety-related duties.
(1) When on a moving train;
(2) When any member of the crew is -
(i) On the ground, or
(ii) Riding rolling equipment during a switching operation; or