Which of the following is not an example of a failure to log-out properly?

The option that indicates a failure to log out properly is a message on the screen or printer from the Network Control System (NCS). This message is typically a notification or prompt resulting from the NCS recognizing an improper shut-down or disconnection. It suggests that, although the system was used, it has not been signaled correctly that the session has ended. Properly logging out should allow the system to clear any data on the screen and confirm that all communications have ceased.

In contrast, the other scenarios—turning off power before logging out, sailing into a shadowing or local RF interference situation, and sailing out of the footprint of a satellite—demonstrate actions that would lead to an improper log-out situation but generally imply an active action taken by the user that overrides the logging process. When executing these actions, there wouldn't necessarily be a message indicating the improper log-out, which makes them less indicative of a failure compared to a persistent notification from the NCS itself.