A method of facilitating the use of a navigational chart, the method performed by a system comprising a computer including a display, the computer being installed in the flight deck of an aircraft and further including a rotary input device (56, 60) which is rotatable by a user using a finger to rotate it in a direction toward or away from himself/herself and which is able to be depressed by said user, the method comprising: providing a view of the navigational chart on the display; detecting movement of the rotary input device (56, 60); and in response to the movement: using one or more geographical locations to identify one or more points on the chart; and panning the view in the display to center in the view at least one of the one or more points; wherein the one or more points include one or more points of a navigation route defined relative to the chart; the method being further characterised by panning the view to center a route point following a route point previously centered in the view in response to detecting rotation of the rotary input device toward the user; panning the view to center a route point preceding a route point previously centered in the view in response to detecting rotation of the rotary input device is not toward the user and detecting that rotation of the rotary input device is away from the user; and wherein when no rotation of the rotary input device away from the user or toward the user is detected (216, 228) and depression of the rotary input device is detected while the system is not being used during flight, the one or more points on the chart including a route point nearest a center of the view are determined and, the panning is performed to center the nearest route point. providing a view of the navigational chart on the display; detecting movement of the rotary input device (56, 60); and in response to the movement: using one or more geographical locations to identify one or more points on the chart; and panning the view in the display to center in the view at least one of the one or more points; using one or more geographical locations to identify one or more points on the chart; and panning the view in the display to center in the view at least one of the one or more points; wherein the one or more points include one or more points of a navigation route defined relative to the chart; the method being further characterised by panning the view to center a route point following a route point previously centered in the view in response to detecting rotation of the rotary input device toward the user; panning the view to center a route point preceding a route point previously centered in the view in response to detecting rotation of the rotary input device is not toward the user and detecting that rotation of the rotary input device is away from the user; and wherein when no rotation of the rotary input device away from the user or toward the user is detected (216, 228) and depression of the rotary input device is detected while the system is not being used during flight, the one or more points on the chart including a route point nearest a center of the view are determined and, the panning is performed to center the nearest route point.