Noggin: Once I was flying Northbound over the Kalahari using the few ground features available to check my postition (something like a specific tree or a dry pond,...).
The A/C I flew was equipped with a wonderful ADF (not my opinion) and later during the flight I began to get a strong signal (audio) and a clear indication of where the needle wanted to go. Great I thought!! Those things really work. Well, not quite because after a little while, despite listening the identifier I realised I couldn't tell where I was anymore. As a matter of fact I could see very large pan that I had never seen before (having done the route regularly). Was I still in the same country or across the border (over a country filled with land mines

). I really didn't know so when I finally spotted a village, without hesitation I landed nearby. I then walked to the local school where the teacher very kindly gave my a lesson of geography on one of these map you get in any classroom.
The irony was that I was actually carrying a GPS on board.... but in the pod
Needless to say that even when I get a very good NDB ident, I don't trust them much anymore.
Makes me laugh when someone tries to tell me how wonderful NDBs are because they aren't. GPS aren't perfect either but I know which one I prefer when flying single pilot SE/IFR in storm(ADF love it)/icy conditions.
For information, we don't shoot GPS approaches but we are BRNAV and when on our homebase NDB approach, we like to monitor it with the GPS. Much better for situation awareness.
Safe Flying.
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If you can't save the engine...save the airframe