9 Aeronautical instruments and controls namely aircraft servo assemblies consisting of a computer, a servomotor, gearbox and clutch all sold as a unit; stall warning systems; electronic automatic throttle controls and lift controls consisting of a computer, servomotor, gearbox and clutch assembly all sold as a unit; speed command computers; accelerometers; airstream angle data computers; lift data computers; computers for speed command and attitude thrust systems; clutch assemblies for power control and control column shakers