finger brake (sheet metal shop tool). Another term for a box brake. See box brake.
finger patch (welded structural repair). A type of patch welded over a cluster in a welded truss-type aircraft fuselage. The patch covers and reinforces damaged areas of the tubes and has fingers that extend out along each of the tubes in the cluster.
finger screen (fuel system filter). A coarse-mesh, small-diameter screen made in the shape of a finger. A finger screen is installed in the end of the outlet line inside a fuel tank to prevent large contaminants from restricting the flow of fuel from the tank.
Small contaminants and water that pass through the finger screen are trapped in finer screens and filters further along in the fuel system.
finishing tape. Another name for surface tape. See surface tape.
finish turning (metal machining). A step in the machining of a metal part in which the part is turned to its correct dimension and given its final smoothness.
FIR (flight information region). An airspace of defined dimensions within which flight information service and alerting service are provided.
fire detection system (aircraft fire warning system). A system in an aircraft that warns the flight crew of the presence of a fire in any of the engines, the cargo area, or the wheel wells.