I dont entirely agree. Air navigation comps use to be popular – maybe they still are, and I did quite a few. They teach you way beyond the PPL how to fly a course and navigate the course accurately. As much as I suspect we all hate the concept of a PLOG, actually well planned and constructed with good viz and especially chucking in the use of any other navaids cross country can be flown surprisingly accurately BUT it is hard work, and very easy to end up making serious mistakes. You definitely cannot allow your attention to wander, or blindly fly on when the scenery doesnt add up. Good viz is also pretty important. Inevitably flying coastal routes or anywhere there are clear line and land features is much easier. Most of us should be able to manage a flight along any part of the UK coast, even long distances. Inland, especially in areas of flat and uninteresting scenery is much more difficult – getting lost over north west France is especially easy for example.
Would you want to do it, probably not, and of course the less you rely on these skills the harder they come, but it can be kind of fun, and maybe worth a trying from time to time in the knowledge you can fall back on that lovely moving map when you think you might be lost. FWIW in most places and countries for that matter far better to ask AT if in doubt, actually they are usually very good, and will give you a steer which will be good for quite large chunks of time, maybe giving you time to sort your navigation out. Even when they claim not to have radar, the cracks reveal themselves when they announce you just flew over such and such 
Silvaire wrote:
If a NOTAM were in place I’d certainly be wary of potential GPS failure in planning my route.
FYI – it is in place. Just for fun I planned a theoretical KSMO – KHHD (Las Vegas Henderson) flight for tonight in ForeFlight and sure enough, there it is. In real life, the NOTAM advising of ‘lights out / night goggle training’ in the en route MOAs would worry me one heck of a lot more!
There’s an interesting philosophical discussion here. Without doubt, GPS is more reliable (in both accuracy and reliability) than other navaid assisted methods of navigation; consequently we rely upon it more. The downside is that such reliance brings greater challenges when it fails. Old-school pilots were taught to adopt a multiple layer approach towards everything they do, somewhat reflected in Peter’s comments about having multiple GPS. However, there is still potential for a single point of failure and, in my slightly jaundiced view, that is something that exercises my mind.
Personally, I always have a chart with me (this may well be an electronic chart) and, call me a bluff old traditionalist, I’ve retained the habit of tuning VOR/NDBs etc that appear somewhere upon my route, even if I’m solely following the magenta. In many respects, it’s no different to tuning the ILS into NAV 2 (or equivalent) when flying an RNAV approach, or vice versa.
I think the circumstances of the GPS loss also matter. If you get caught out by a properly NOTAMed test (which is unlikely to actually kill GPS, at least in my limited experience), then that’s on you for not falling back on VOR/DME or I Follow Roads navigation, as appropriate. If it’s a true system wide GPS failure (CME, USAF decides to shut the system down?, other extreme circumstances) busting CAS is likely to be the least of anyone’s problems.
At any rate, I think the appropriate response depends on what other equipment the plane has. If you’re flying IFR, hopefully you have at least a NAV radio and glideslope to get you down. If you’re VFR and just follow Garmin Pilot or whatever, then you’re truly hosed unless you have a decent sense of location and can navigate by external references. (Which you should be able to do anyway, unless you’re VFR on top where that’s legal?)
The other decision is if a GPS failure is a land at the nearest airport issue or a minor inconvenience. That depends on airspace structure, your flight rules, and the weather. Any old plinker should be able to tune the nearest on airport VOR and head straight there. (Assuming it’s not on the other side of class A/B airspace.)
I was going to write much the same as Patrick.
For me, the big difference would be if the failure was known before flight or not.
Before I started to use GPS, I would plan my flights so that the turning points were at big easily identified features. By easily identified, I mean that if I was off course, I could still see them from a few miles away, and if I was over them, there would be no doubt about it. Good features were lakes, edge of an easily identifiable mountain range, particularly large towns or cities and particularly identifiable joining of big rivers. Bad were small villages, castles…..things that you can only see from overhead or where one looks much like the other.
If I knew I was doing a flight without GPS, I’d plan all my turns at these bigger waypoints.
With GPS, waypoints are often small villages, IFR waypoints, and even random ones which just give me enough room to avoid a particular airspace. Apart from the small villages, these would impossible to find as they don’t physically exit. So a loss of GPS in such a situation would require some quick re-planning. I always carry a plog, because it takes no effort…..my GPS software produces it for me. But if the waypoints are IFR points, it probably won’t do me a lot of good other than in the initial stages where I have something to follow while coming up with a new plan.
Of course if the GPS outage is widespread and unexpected, then ATC might get overloaded with pilots asking for help!
The other point is that it would make a huge difference where it happened. A trip from EIWT Weston, to the Arran Islands, wouldn’t be an issue. It’s a route I know well, and there isn’t a huge amount of airspace to be worried about infringing. But if it were to happen in a complicated, crowded bit of airspace that I don’t fly in all that often (like the south east of the UK, or around the Paris region) then things might be more difficult!
172driver wrote:
it is in place. Just for fun I planned a theoretical KSMO – KHHD (Las Vegas Henderson) flight for tonight in ForeFlight and sure enough, there it is. In real life, the NOTAM advising of ‘lights out / night goggle training’ in the en route MOAs would worry me one heck of a lot more!
That’s a relatively easy one minus GPS: stay low to the Rose Bowl, then climb and follow the base of the mountains east to Cajon Pass, remaining north of Highway 210. Then follow Highway 15, remaining south of the Highway to avoid the MOAs. Call KHND tower overhead Jean, make straight in 
214 nm by Old School IFR
Silvaire wrote:
That’s a relatively easy one minus GPS: stay low to Pasadena, then climb and follow the base of the mountains east to Cajon Pass, then follow Highway 15, remaining south of the Highway. Call KHND tower overhead Jean, make straight in
True, that’s real I *F*ollow *R*oads IFR. Even easier: duck under the Bravo around DTLA, then climb via POM direct HEC, direct BLD till you get +/- the LAS 320 radial, turn north and straight in. The 430 & S-Tech 60 will get you there all by themselves
But I guess, we digress…….
Islamic State presumably uses GPS to guide its drones
I suspect we will see a fair few GPS outages over the next decade or two.
kwlf wrote:
I suspect we will see a fair few GPS outages over the next decade or two.
Not too sure about that, at least not widespread. GPS is embedded in so many functions of our society that – short of all-out war – it’s very hard to turn this off over a wide area. Locally, that may well be very different, although I have no idea how precisely this can be done.
