Right, let’s talk about getting lost — because it happens, even to good… — Page 233, Lesson 216

Right, let’s talk about getting lost — because it happens, even to good navigators. You’re flying along, and suddenly you’re not quite sure where you are. The temptation is to carry on regardless and hope it sorts itself out. Don’t. The moment you realise you’re uncertain of your position, treat it as a critical phase of the flight. Start immediately to resolve the uncertainty using every aid you have available. Here’s the trap though: when pilots get uncertain of position, they often over-concentrate on the navigation and forget to check fuel and aircraft systems. So the very first thing you do is check your fuel and aircraft systems. Then you follow a ‘lost’ procedure. And if you’re still uncertain when you’re due at a turning point, you turn on time — that is, on your ETA, your estimated time of arrival — and you obey the rules below. Let me walk you through the lost procedure step by step. First, check your compass and ASI — your airspeed indicator — to make sure you’re actually flying the planned heading and speed. If you’ve drifted off heading, that alone could explain your uncertainty. Second, if meteorological or airspace restrictions don’t prevent it, climb. Climbing increases your visual and radio horizon, which gives you a better chance of seeing or receiving something to fix your position. Third, fix your position using all aids available. That means VOR/DME — VHF omnidirectional range and distance measuring equipment — VDF, which is VHF direction finding, a radar fix, or a visual fix. Fourth, if you’re restricted to visual methods — that is, map reading — then you calculate a DR position. DR stands for ‘Deduced Reckoning’, though it’s commonly known as ‘Dead Reckoning’. The DR position is deduced using the position and time of your last known accurate fix, and the track, ground speed, and time flown since that fix. So you take where you definitely were, and you project forward along your track at your ground speed for the time elapsed. Fifth, draw a ‘circle of uncertainty’ around the DR position. The circle is normally drawn with a radius of 10% of the distance flown since the last fix. So if you’ve flown 100 nautical miles since your last fix, your circle of uncertainty has a radius of 10 nautical miles. Remember, the DR position continues to move along track, and the circle of uncertainty gets larger with time — the longer you go without a fix, the bigger your uncertainty grows. Now, with that circle drawn, you map-read from ground to map. That’s the key direction — you look at the ground, find a large visual feature, and then locate the aircraft on the map with reference to that feature. On most occasions, your aircraft position should lie within the circle of uncertainty. Sixth, if you’re still in difficulty, consider turning towards a good visual line feature outside the circle of uncertainty — for example, a coastline, a motorway, or a main railway line. On reaching that line feature, turn and follow it until you find a definite visual checkpoint from which proper navigation can be resumed. Now, a few cautions. Be careful that you don’t fly towards high ground in poor weather below safety altitude. And be careful that you don’t fly into controlled airspace without clearance. Always keep a good lookout, monitor your fuel and aircraft systems, and remember that you can use the Emergency Fixing Service on 121.5 MHz — that’s the VHF frequency for a PAN call, which is the urgency call, less urgent than a MAYDAY but still a call for assistance. So the whole lost procedure is: check compass and ASI, climb if you can, fix your position with all aids, if visual only then calculate a DR position, draw your circle of uncertainty at 10% of distance flown, map-read ground to map, and if still stuck, head for a line feature and follow it to a checkpoint. And throughout, keep your fuel and systems monitored, and don’t forget 121.5 MHz for the Emergency Fixing Service. Now, the rest of this section moves into topographical maps and map reading — chart symbols and how to read the ground from the map. That’s where we’ll go next.