Hi,please help me to understand the 757 autopilot. There are three buttons to turn the A/P on (the three A/P ENGANGE switches on the upper right portion of the autopilot MCP). The switches are named L, C and R. Now, which switch is good for what?The 757 is my first airliner, this is a complete new world, but very facinating. Thanks to PMDG for bringing us that bird. Thomas

Welcome to the world serious airliner sims :-) The full details are covered thorougly in the manual, but basically the 757 has three separate, identical autopilot systems (identified as Left, Center, and Right because of where the actual boxes are located in the electronics bay). For most phases of flight, you only need ONE of them to be engagued and it does not matter which one. They are identical, and serve as backup in case one fails.However, during a CAT III auto-land, you must engague all three simultaneously. In this case, since extreme precision is required, they work together, constantly checking each other for errors. Hope this helps to get you started. Enjoy.Andrew

>However, during a CAT III auto-land, you must engague all >three simultaneously. Actually 2 should be enough (AutoLand 2). But you can engage all 3 for extra redundancy (AutoLand 3).Michael J.