He was right IMHO.
There is a “pilot forum famous” UK instructor who flew a Cessna with a student into rising terrain on a night navex. No GPS. Due to the terrain rising fairly slowly, they both survived but were extremely lucky. There was very little left of the Cessna – mostly a pile of bent up metal. IMHO the student could have sued on that one (maybe he did). So you (the instructor) have to use the best tools, regardless of syllabus restrictions that may apply to the student.
But actually there are almost no syllabus restrictions on GPS in the PPL. There are just a few specific exercises in which GPS cannot be used, and that’s it.
They have jammed GPS recently in Scotland for military exercises.
But going back to the question of which is better to use as a backup, if you find yourself suddenly without GPS signal, how likely are you to know where you are and be able to work out which way to go in order to regain a known landmark?
If you find yourself suddenly uncertain of position, you can look at the GPS. It doesn’t matter how you came to get into that situation or whether you misread a landmark or can’t remember how many minutes since the last waypoint. To be honest, I’d be hard pushed to remain aware of these things if I wasn’t forced to keep them well in mind.
I think it’s pointless, especially with the EU’s complicated airspace structures. I had to use dead reckoning on my first cross country in the States. I haven’t used it since.
What I would suggest is a better and more useful exercise, is to make sure you always follow along on the map or a second back-up device. If I still had my FAA CFI today, which lapsed decades ago, I would teach my students to use the GPS and then switch it off mid-flight and ask them to divert using a paper map or a back-up such as VOR etc.
Dead reckoning is old school. Situational awareness is what should be taught.
-Jason
But going back to the question of which is better to use as a backup, if you find yourself suddenly without GPS signal, how likely are you to know where you are and be able to work out which way to go in order to regain a known landmark?
You shouldn’t need to work out which way to go. If you’ve been flying your GPS course with reasonable accuracy (flying a good honest heading) when the GPS was working, when it fails you’re still on course! If you roughly know when you last passed something significant on your GPS screen or when you last looked at a land mark on the ground, you can work out with a very high degree of confidence where you are right now. Also if accurately following your GPS course you’ve already got your wind correction in.
Turning back or changing course at that stage will not really improve matters. Looking ahead at what the next significant landmark on your original course will help you far more.
I wouldn’t do it for “fun”, but on the other hand I don’t want to forget the skills but if you asked me to start drawing fan lines and stuff, I might well struggle a bit, like I’d have to think for a few minutes on how to use the whizz wheel again. For me dead reckoning was straining my back to look over the top of the instrument panel for some town or other landmark and constantly being bothered by time and distance adjustments in the air. Now it prefer to use GPS to make life a bit easier and actually enjoy the flying and looking out the window at what’s around me and not constantly waypoint hunting.
There is an unfortunate assumption in some areas of GA that people who fly 100% on the GPS are not doing any route planning.
I know this is true for some pilots (probably more these days, with many flying with a certain very popular UK moving map product which is designed to hold your hand tightly 
) but most of the ones I know do work out the route before they fly, and could do a VOR/DME fallback. Also if I was under a radar unit, I would tell them – notwithstanding the ridicule one would get on some UK aviation sites the following day 
Enjoyed the thread, especially alioth’s flight of passage in a C-140.
Alioth’s described the technique in an eighty knotter very well – I just draw a line on the map, mark distance in nm and track to the nearest five degrees, and then use the most basic of trig to work out eta and wind correction. Sparky Imeson’s Mountain Flying Bible has the sine and cosine table in 15 degree lines, but the clock code works fine.
I think DR practice does keep your situational awareness reasonably keen – suddenly abandoned railways, old peri tracks, subdued river beds, all take on meaning. You do get false positives but then a bit of detective work should get you back on plan.
‘Sweep hand’ is just an analogue watch with a second needle.
Agree that with complex airspace there is probably more pilotage/feature crawling than traditional dead reckoning.
The Lysander crews used DR to find a couple of torches in a darkened field in Southern France, hoping that some moonlight on a river might confirm their calculations – but then no worries on airspace infringement!
What I would suggest is a better and more useful exercise, is to make sure you always follow along on the map or a second back-up device. If I still had my FAA CFI today, which lapsed decades ago, I would teach my students to use the GPS and then switch it off mid-flight and ask them to divert using a paper map or a back-up such as VOR etc.
That exercise would be great for BFRs etc, especially for those using handheld devices as primary VFR navigation in simple aircraft, as I believe they should in complex airspace. One approach would be to turn off the GPS just as the student thinks he’s ‘almost there’ but hasn’t quite got the airport in sight. Then he’s got several things to do at once.
Moving map GPS’s that display the actual VFR chart have made the screen to paper transition much easier, and thereby enhanced safety a lot… as long as the pilot looks at the features on the chart and not just the little aircraft and the magenta line.
And when flying lower, there is such a wealth of visual clues that it really takes a fool to loose track. There are motorways, canals, railways, cities, power plants, all of them in great number. The main danger is indeed mistaking one for the other.
I agree 100%. I looked up “dead reckoning” aka “ded reckoning” and unless you are flying on top or across vast oceans with no visual clues and no radio navigation, then I wouldn’t even call it “dead reckoning”. At least in Norway “ded reckoning” (“bestikknavigasjon” in Norwegian) is not the same as navigating by VFR rules, but only a subset used mainly in circumstances with no visual or instrumental clues, and of course no GPS. One could of course argue that ded reckoning techniques are used in “old school” VFR planning, but when you can simply look out the window to see where you are at any time, this is not navigation by dead reckoning in my opinion.
power plants
There is also Dead reckoning where you fly over one of these in France and the taxpayer sends a fighter to guide you the rest of the way….
