MechJeb2 Not doing anything

[briocheman21]

Whenever i try to use the autopilot it either does nothing and crashes into the ground. Can anyone help? The plane im using works fine and I have the latest version of MechJeb and the part is installed on my plane. 

[James Kerman]

Welcome to the forum @briocheman21, your issue has been moved from KSP discussion because this is more of a tech support question.

[Guest]

Are you setting the options on the autopilot popup? It's not the most intuitive but say you're wanting to hold a heading of 90 deg, you need to put that into the heading box and then make sure the checkbox for heading is checked. There is then an autopilot master on/off button as well at the top. 

[jimmymcgoochie]

Did you actually turn it on?

MJ has many different modes, are you talking about the aircraft autopilot? You need to set the flight parameters like speed, altitude, heading and then engage the autopilot; just turning it on will usually default altitude to 0 (which isn’t a very good idea!), and setting the parameters without engaging the autopilot won’t do anything and the plane will just keep flying uncontrolled (if SAS is off, though SAS doesn’t do too well with planes anyway) and you'll probably end up crashing.