In-Flight Navigation: Visual Navigation, Position Fixing and Lost Procedures
Visual navigation and map reading
Visual navigation uses ground features, timing and heading to confirm position. Good practice: identify large, unambiguous features (coastlines, large lakes, motorway junctions, airfields), compare them with the chart, and use the "clock code" and the 10° cone from the nose to judge relative position. Map reading traps include confusing similar features (two parallel roads), misjudging scale, and forgetting that the chart is oriented to true north while the aircraft is heading elsewhere. Orient the chart with north up and mark the aircraft's position regularly.
Position fixing
Methods include visual pinpoint, bearing and distance from a VOR/DME, two bearing lines, radar and GNSS. A fix is only as good as the accuracy and geometry of the inputs; crossing lines at shallow angles give poor fixes. Always record time and heading at the fix so you can update the DR position.
Lost procedures
The classic sequence: maintain heading and altitude, note the time, climb if safe (better visibility and radio range), and try to identify a line feature (coast, river, motorway) to follow. Use radio aids, ask for assistance (ATC, radar), and consider a precautionary diversion. Do not wander; fly a deliberate pattern or a known heading to a known feature. Traps in questions include choosing to descend or to change heading randomly, or forgetting to note the time of the last confirmed fix.
Worked example
At 120 kt you pass a town and 12 minutes later reach a lake not on your planned track. You have flown 24 NM. If the lake lies 8 NM right of track, your average drift is about arctan(8/24) ≈ 18° right, suggesting a wind from the left.
Rule of thumb
"Time, heading, feature, radio": record time, hold heading, identify a line feature, then use radio aids or ATC.