Whenever a pilot encounters a potentially hazardous meteorological condition or an irregularity in a ground facility or navigation aid in flight, the knowledge of which the pilot considers essential to the safety of other flights, the pilot shall notify an appropriate ground radio station as soon as practicable.
[Doc. No. 16097, 43 FR 46783, Oct. 1, 1978, as amended at Amdt. 135-1, 44 FR 26737, May 7, 1979; Amdt. 135-110, 72 FR 31684, June 7, 2007]