From X-Plane SDK
XPLMCameraControlDurationThis enumeration states how long you want to retain control of the camera. You can retain it indefinitely or until the user selects a new view.
|xplm_ControlCameraUntilViewChanges||1||Control the camera until the user picks a new view.|
|xplm_ControlCameraForever||2||Control the camera until your plugin is disabled or another plugin forcably takes control.|