How to add a new custom flyCam

I want to custom control of cam. I have override the FlyByCam and rename it as Flybycam_Customed.

In simpleInitApp()
{
flyCam.setEnabled(disable);
Flybycam_Customed fly= new Flybycam_Customed(cam);
}

I code like this and want to disable old flyCam firstly . Then to apply new custom Flybycam . But it didn’t work. It seems that no input was accepted. Anyone knows how to do this kind of replacement?

What about

fly.registerWithInput(inputManager);

?

To disable the existing fly cam just remove its app state… or never even add it (if you specifically pass the app states you want on the super() constructor).