Note that "most aircraft" maybe applies if you count globally and include all the ones sitting still in a hangar.
Larger aircraft never fly on NDB. Everything with a flight management system (which is all airliners currently in service in developed countries) will use GPS + DME/DME + inertial systems as backup and auto-tunes VOR also as a backup. The computer will not use NDB to update the position, even if GPS fails.
We do fly procedures (holdings for example often in Europe) based on NDB, but we do it using the GPS position of the NDB, not the actual radio signal.
I helped ferry an open cockpit biplane from Colorado to the Chicago area with more or less basic VFR equipment - compass and maps. (We did have a handheld GPS... which did not seem to stay connected) Eight hours of hand flying was a wild change of pace from the normal equipment we were use to. Started 'chasing' the compass when my co-pilot wanted a course modification... and I had missed our heading while already in turn. Embarrassing. It had been a long time since I actually tried navigating with an actual compass, and had to pay attention to mentally adjusting for compass errors in acceleration and turns.
With a plane and engine like you were flying, if you were getting low on fuel and flying over a highway with little traffic, could you have successfully refueled at a roadside reststop?
In this video from Alaska they land at a roadside gas station and refuel in a fuel emergency. In an in-flight emergency you can deviate from any rule... still poor planning by the pilot.
Not OP, but my guess is that their fuel requirements are different than automotive gasoline. Doesn't mean it won't work, but might not work as expected...
I haven't seen an airplane with NDB or ADF ever, and I've been regularly flying for about 5 years. They are super rare to find on charts, at least in the US. VOR is still common but most people use GPS.
NDB in the US is almost unheard of anymore. I don’t know a single pilot that willingly flies an NDB approach. I am not sure there are any NDE approaches still published in the US. And VOR in the US is being slowly phased out as well. As a side note, HIWAS is being ended in January. I don’t know of any GA aircraft that are manufactured in the past 20 years that had NDB as standard equipment and DME in modern aircraft is pretty rare (true DME, not the GPS substitute.)
I wouldn’t say “most aircraft” rely on NDB — at least not most IFR-certified aircraft actually flying. It’s pointless to use it. ILS and RNAV are by far the most common. NDB approaches aren’t required anymore on an instrument checkride.
A lot of my navigation training involved a stop watch, map and a compass just a year or so ago!
--- https://en.wikipedia.org/wiki/Non-directional_beacon https://en.wikipedia.org/wiki/Radio_direction_finder#Automat... https://en.wikipedia.org/wiki/VHF_omnidirectional_range https://en.wikipedia.org/wiki/Course_deviation_indicator