A system comprising: a camera configured to capture an image within a flight deck of an aircraft; a non-transitory memory maintaining program instructions and one or more authorized faces; and one or more processors configured to execute the program instructions maintained on the memory, the program instructions causing the one or more processors to: receive the image from the camera; determine a detected face within the image is unauthorized, thereby indicating an unauthorized user is disposed within the flight deck; wherein the one or more processors detects the detected face by a facial detection algorithm; wherein the one or more processors determines the detected face within the image is unauthorized by comparing the detected face with the one or more authorized faces; and by controlling avionics systems of the aircraft, change a mode of the aircraft from a full authority mode to a reduced authority mode in response to determining the detected face within the image is unauthorized; wherein the unauthorized user has full authority to control one or more user interface elements of the aircraft in the full authority mode; wherein the unauthorized user has reduced authority to control the one or more user interface elements of the aircraft in the reduced authority mode; wherein a limit is placed on a rate-of-climb, a rate-of-descent, a pitch angle, a roll angle, a yaw angle, and a thrust in the reduced authority mode; and wherein the unauthorized user is prevented from moving the aircraft outside of a preset flight path in the reduced authority mode; and characterized in that: in the reduced authority mode, not all authority is taken away from the user to control one or more flight surfaces. a camera configured to capture an image within a flight deck of an aircraft; a non-transitory memory maintaining program instructions and one or more authorized faces; and one or more processors configured to execute the program instructions maintained on the memory, the program instructions causing the one or more processors to: receive the image from the camera; determine a detected face within the image is unauthorized, thereby indicating an unauthorized user is disposed within the flight deck; wherein the one or more processors detects the detected face by a facial detection algorithm; wherein the one or more processors determines the detected face within the image is unauthorized by comparing the detected face with the one or more authorized faces; and by controlling avionics systems of the aircraft, change a mode of the aircraft from a full authority mode to a reduced authority mode in response to determining the detected face within the image is unauthorized; wherein the unauthorized user has full authority to control one or more user interface elements of the aircraft in the full authority mode; wherein the unauthorized user has reduced authority to control the one or more user interface elements of the aircraft in the reduced authority mode; wherein a limit is placed on a rate-of-climb, a rate-of-descent, a pitch angle, a roll angle, a yaw angle, and a thrust in the reduced authority mode; and wherein the unauthorized user is prevented from moving the aircraft outside of a preset flight path in the reduced authority mode; and characterized in that: in the reduced authority mode, not all authority is taken away from the user to control one or more flight surfaces. receive the image from the camera; determine a detected face within the image is unauthorized, thereby indicating an unauthorized user is disposed within the flight deck; wherein the one or more processors detects the detected face by a facial detection algorithm; wherein the one or more processors determines the detected face within the image is unauthorized by comparing the detected face with the one or more authorized faces; and by controlling avionics systems of the aircraft, change a mode of the aircraft from a full authority mode to a reduced authority mode in response to determining the detected face within the image is unauthorized; wherein the unauthorized user has full authority to control one or more user interface elements of the aircraft in the full authority mode; wherein the unauthorized user has reduced authority to control the one or more user interface elements of the aircraft in the reduced authority mode; wherein a limit is placed on a rate-of-climb, a rate-of-descent, a pitch angle, a roll angle, a yaw angle, and a thrust in the reduced authority mode; and wherein the unauthorized user is prevented from moving the aircraft outside of a preset flight path in the reduced authority mode; and characterized in that: in the reduced authority mode, not all authority is taken away from the user to control one or more flight surfaces.