Autopilot 'Z' and AFS Switches

[houphad 0]

Hi,I'm confused between these two and I would like to clarify the following points:1- What is the difference between pressing the 'Z' on the keyboard and pressing the AUTO FLIGHT button on the center glareshield?2- Is the 'Z' for all FMC SPEED, NAV & PROF? So pressing it wil enable/disable all the 3 systems together?3- If AFS was engaged and I pressed 'Z', what should happen? I suspect that the AFS OVRD OFF 1 & 2 switches be pressed down but that doesnt happen. And being so, which button/switch on the MD-11 cockpit gets animated when I press the 'Z'?Can someone clarify this please?Thanks :)Fouad

[Tabs 2,790]

Fouad,The AFS OVRD OFF switches should never be touched in normal operation of the airplane.The MD-11 has AP and A/T disconnect switches (located on the yoke and throttles in real life) that you need to assign to keypresses in the PMDG Options menu. Those are what get used to disconnect them in normal operation.The autoflight button has different functions depending on when you press it. Before takeoff it acts to arm both the FD modes and the AT. Once in flight if you press it, it's the equivalent of a Boeing's AP CMD switches.

[houphad 0]

Thanks for the clarification...So I understand from what you said that the 'Z' triggers the A/P on the Yoke OFF which in turn dis-engages the AFS. Right? Its only an A/P disconnect. So if I press it again it just clears the warning but it will not re-engage the AFS?And there is another key for the A/T OFF on the throttle quad. Which acts similar to the above. Pressing it will disconnet the A/T, dis-engage the FMC SPEED and pressing again will not re-engage the FMC SPEED. The second press is just to clear the alarm.Am I close enough?Fouad

[PHXMD-11 86]

Right on target.Though I don't think there is a warning for A/T disconnect.

[houphad 0]

Cool. thanks