What information must be included to cancel a distress message?

To effectively cancel a distress message, it is essential to issue a MAYDAY message followed by a silence signal. This serves as a clear and standardized communication to notify all stations that the previously issued distress alert is no longer in effect. The use of the MAYDAY signal indicates that the distress situation has changed, and the silence signal reinforces this cancellation by ensuring that no further help is expected.

In aviation communications, clarity and brevity are paramount, particularly in distress situations where every moment counts. The MAYDAY followed by a silence signal allows for immediate recognition by air traffic controllers and other pilots that the emergency has been resolved, preventing unnecessary concern or action in response to the distress call.

Other options, while they might seem relevant, do not effectively fulfill the requirements for cancelling a distress message. They either do not provide the necessary communication standard or lack the focused, immediate clarity that is crucial in emergency management.