I'm waiting for the first aviation GPS nav system to pull the automobile trick and refuse to accept programming while in flight. "Sorry you may not select an emergency landing airfield as a new destination, the aircraft is in flight, please land the aircraft then for your safety the GPS configuration screen will be unlocked". Its merely obnoxious nanny when a car driver is alone, but its incredibly frustrating when the car or airplane has a "copilot" dedicated to the task.