Aircraft navigational instruments; Aircraft instruments, gauges, and apparatus, namely, for measuring and displaying, oil pressure, oil temperature, fuel level, fuel pressure, fuel flow, engine rotation, engine revolutions, voltage, engine manifold pressure, outside air temperature, altitude, time and time zones, turbine inlet temperature, cylinder head temperature, engine gas temperature, carburetor temperature, air pressure, interstage turbine temperature, and torque; Aircraft and airplane instrument kits comprised primarily of navigational instruments, fuel gauges, temperature gauges and pressure gauges; Aircraft engine temperature analyzers; Electric annunciator warning instruments, panels, and lights; Probes for measuring, namely, cylinder head pressure, turbine inlet temperature, exhaust gas temperature, oil temperature, carburetor temperature, surface temperature, and gas level; Fuel flow electrical transducers; Air pressure transducers that convert hydraulic or pneumatic pressure into analog electrical signals for monitoring and controlling hydraulic or pneumatic systems; Remote electric switches to control multiple instruments and gauges; Aircraft and airplane software for measuring and recording data