distress frequency การใช้

Operated on the international distress frequency of 500 kHz.
The pilot followed time-honored emergency procedures, he said, including broadcasting his intentions on the universal air distress frequency.
Its patrol ships at sea and the communications center at Haulbowline maintain a 24-hour watch on all distress frequencies.
Subsequent to the SOLAS ) conventions established the 500kHz maritime distress frequency monitoring and mandated that all passenger-carrying ships carry licensed radio telegraph operators.
Those early beacons, designed for both manual and, in the event of a crash, automatic activation, were to broadcast their signals at 121.5 MHz-- the distress frequency long used by aviators.