Chart Wise: Understanding RNAV

RNAV is more than just point-to-point navigation. All GPS RNAV approaches also have performance parameters baked into the procedure (for instance, required navigation performance values and distance holds instead of timed holds), allowing refinements to make them more accurate and efficient. The granddaddy of all GPS RNAV approaches is WAAS LPV, which offers similar approach minimums as ILS. Today there are more than 3,600 WAAS LPV approaches in the United States serving nearly 1,800 airports.

COURSE INDICATOR: The approach procedure and its waypoints are shown in the center of the plan view of the approach chart. The same procedure and waypoints will be shown once the approach is activated on your GPS, making it easy to know if you are on the right track.

RAIM: RAIM stands for receiver autonomous integrity monitoring. It’s not a type of approach but rather technology that assesses the integrity of GPS signals. If, for example, you fly an LNAV/VNAV procedure and don’t have WAAS, you are required to check predictive RAIM on your GPS receiver before starting the approach.

Chart courtesy of Jeppesen