The 747-400 has a Crew Alertness Monitor. It will generate an Eicas message "Pilot input" required when no input has been detected. A press of the FMC, a brief click of the microphone, or an auto-pilot input clears the message.
If the message is not cleared, ie u are sleeping. The message gives and aural warning, and if it is still ignored I think it gives a constant aural warning. Not too sure tbh. As to date I have never seen it go beyond "pilot input".
So far. :P
Last edited by L337; 5th Nov 2007 at 06:43.
Reason: spelling