仪表等级飞行员理论培训stage5-213 RNAV-GPS APCH.ppt

Instrument Approaches GPS and RNAV Approaches Overview GPS and VOR/DME RNAV approaches provide greater design flexibility With GPS, smaller airports can have instrument approaches with no need for ground based navigation equipment Procedures similar to other approaches, but equipment is more complex What’s Coming! The Difference in the Dials Where are the needle and ball? GPS Equipment Requirements As a sole source for nonprecision approaches: Receiver Installation method Supplements section of AFM will tell you if the equipment meets FAA requirements Handhelds not certified for IFR navigation (but may be used as aid to situational awareness) Receiver Autonomous Integrity Monitoring (RAIM*) Continually monitors reliability of GPS signal 4 satellites is enough for triangulation 5 satellites gives you integrity monitoring Prediction of RAIM* availability Information is available from FSS as to which satellites are available for your ETA. Other Requirements IFR approved GPS requires: External Annunciators – ability to display VOR/HSI info, and be advised of error, waypoint etc. messages. CDI display When GPS is selected the annunciator alerts you to: receiver messages waypoint passage approach mode enabled waypoint hold Navigation Database Loaded by magnetic card waypoints fixes station identifiers Updated regularly MUST be current for IFR navigation You may not edit database, but you can add user-defined waypoints for VFR use only GPS Differences For distance, GPS is always TO the next waypoint Along Track Distance (ATD) Different from DME because it’s not slant range Discrepancy with “DME” varies with altitude and distance from station. GPS is actual distance. Other GPS Differences Heading may vary slightly from published courses due to algorithm used by GPS for variation Waypoint Sequencing TO-TO Navigation Hold Mode suspends auto-sequencing Approach mode drop after FAWP requires you to go missed approach Do NOT touch GPS between FAF MAP… that is the F