VFR Navigation Diverting Richard Champion

Diverting Aim Objective Airmanship Agenda To learn how to to divert to an alternate destination. Objective By the end of this briefing, you should be able to use your diversion rule and wind star to plan a diversion to an alternate destination in flight, with the minimum of mental effort. Airmanship Good navigation, avoiding airspace busts Agenda Equipment needed How to use it Examples Summary

Equipment Required Wind Star Diversion Rule Pre-calculated adjustments for forecast wind. Allows diversion headings and ground speed to be estimated with the minimum mental effort. Diversion Rule Makes it easy to measure distances and estimate arrival times.

How to divert Mark current position on chart. Loiter if necessary. Mark diversion destination on chart. Draw free hand line from present position to diversion destination. Estimate the no wind magnetic heading by comparison to a nearby VOR rose. With practice you will be able to judge this by eye with surprising accuracy. Turn onto heading and note time (or start watch). Interpolate wind correction angle and ground speed from Wind Star. Note on chart. Adjust heading to wind corrected value. Use diversion rule to estimate distance and ETA using ground speed. Fly heading until ETA is up. Do regular FREDA checks. On long diversions, use Standard Closing Angle to correct back to planned track if required.

Example 1 TAS 90Kts, heading 051°, ETA +32 mins WCA -12 GS 95 32nm, 20 mins After 14 minutes – actual position Uckfield Divert - new destination Lydd Use wind star to estimate wind correction angle and ground speed Calculate ETA allowing for time already on stop watch. 20 – 4 = 16 minutes Fly heading, FREDA check, use Standard Closing Angle if off track Use diversion rule to measure distance and read off time required. Mark Uckfield and Lydd and draw line by hand Estimate heading - 100° Turn on to100°, start watch Adjust heading 100° -12° = 088° 350/20

Example 2 TAS 90Kts, heading 051°, ETA +32 mins Divert - new destination Rochester Calculate ETA allowing for time already on stop watch. 22 – 4 = 18 minutes Use diversion rule to measure distance and read off time required. Fly heading, FREDA check, use Standard Closing Angle if off track After 14 minutes – actual position Uckfield Use wind star to estimate wind correction angle and ground speed Turn on to 030°, start watch Estimate heading - 030° Adjust heading 030° -8° = 022° Mark Uckfield and Rochester. Draw line by hand WCA -8 GS 75 27nm, 22 mins 350/20

Summary We have learned : How to plot current position, diversion destination and track required. How to estimate the no wind heading. How to use the wind star to adjust the no wind heading to allow for the forecast wind. How to use the wind star to estimate ground speed. How to use the diversion rule to measure distance and estimate time of arrival at diversion destination. Always prepare a wind star and take your diversion rule with you on cross countries.