The navigation system calculates and shows aircraft attitude, altitude, and position in relation to the surface of the earth. This system receives data from other aircraft systems, ground stations, and environmental conditions around the aircraft. The pilots are shown information on aircraft movement including speed and direction of travel in all three axes. Present position and future position are also shown.

The flight environment data system collects environmental data and supplies nonelectrical sensor data to the air data computers (ADCs) and an integrated standby instrument (ISI). The system processes the environmental data and transmits digital data, other avionics systems, and the electronic flight instrument system (EFIS). The flight environment data system includes a pitot static and temperature system, standby air data system, and air data system.

The attitude and direction system determines and displays the aircraft pitch, roll, and heading data and provides this information to other avionic systems. The attitude and direction system supplies acceleration data to assist the flight control system performance and also provides an auxiliary display that shows continuous indication of the aircraft heading in the event of EFIS failure. The attitude and direction system includes an attitude and heading reference system and a standby compass.

The independent positioning determining system provides the position of the aircraft in relation to an object without the use of ground installations. The system determines areas of high precipitation along or near the flightpath and supplies ground map displays. The system provides data to prevent accidents caused by controlled flight into terrain (CFIT) and windshear conditions. The system provides visual and aural warning when other transponder-equipped aircraft are within the aircraft surveillance range. The system provides the pilots with accurate data about the aircraft height above ground level. As an optional feature, the Challenger 300 aircraft can detect and display areas with lightning activity. The independent positioning determining system includes a weather radar system, terrain avoidance warning system, a traffic alert and collision avoidance system, radio altimeter system, and lightning detection system.

The dependent positioning determining system uses signals from ground installations, satellite transmitters, and airborne transponders to determine the aircraft position. The dependent positioning determining system includes a VHF navigation system, distance measuring equipment system, air traffic control transponder system, and global positioning system.

The flight management system (FMS) combines navigation data from different systems and sensors to calculate the aircraft position. The FMS supplies lateral and vertical navigation guidance and flight planning capability worldwide. The FMS control display unit (CDU) enables the flight crew to control all the flight management functions from one location. The FMS also has the capability to control the communication and navigation radios and supplies aircraft performance management data.

The navigation system has interfaces with the other aircraft systems that follow:

• Auto Flight
• Communications
• Flight Controls
• Integrated-Avionics Processor System (IAPS)
• Electronic Flight-Instrument System (EFIS)
• Position and Warning.

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