There are two basic modes of operation that an autopilot can be engaged in, control wheel steering (CWS) or command (CMD mode. In control wheel steering, the autopilot receives its pitch and roll inputs from the control wheel. The aircraft will remain where you put it. If you move the control wheel with a force of four pounds or more, the aircraft will respond. When you release the controls, the aircraft stays where you put it. Remember, only one autopilot can be engaged at a time.When an engage lever is moved to CWS, it is held in that position electrically after the autopilot/flight director computer determines that the system is working properly. Anytime the signals are not valid, the lever will automatically drop to the OFF position.
This is the mode that caused Eastern so much trouble in the Everglades. EAL deactivated this mode and their 757s never had CWS mode.
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