> GPS is not essential to air navigation. It’s nice to have, and there are some approaches that legally require it to be operational in order to fly them (IFR procedures) but aviation has other systems in place to guide aircraft under conditions where visual flight navigation is impossible.
This has not been the practical reality for many years for IFR flights (arguably not for VFR flight either but some of the good old boys will still argue that you should still be using a map and compass).
In Europe the minimum requirement has been B-RNAV and aircraft are controlled with reference to intersections which have no defined relationships with underlying VORs, and an expectation of being able to navigate direct to one from any arbitrary point in space. Airliners generally get away with this because they have DME-DME disciplined INS. Smaller aircraft, well the backup is vectors from ATC.
This approach is wrong though, as we’re now seeing.
GPS is comically easy to jam or spoof and assuming it will work all the time is just a silly, dangerous assumption.
We just happened to live through a brief period where you could believe that
Yeah, I agree that GPS is too easy to jam and should ideally not be used exclusively but if you are flying anything from a newish C172 to a Cessna Citation (or any other non-long haul business jet) it is the reality.
Annoyingly all of these systems have VOR and DME equipment, it would be trivial to have a back up position to well within en-route navigation accuracy limits and certainly close enough to prevent this kind of accident. But regulation and certification requirements being what they are they are no one does it.
In an ideal world we'd have some kind of INS but the ring laser gyros and accelerometers required are stubbornly expensive.
In this case the call was coming from inside the house. Another win for uncle Sam.
Does Europe not have VORs?
Of course - though many of them have been decommissioned or are in the process. Though recent developments have probably reduced the enthusiasm for removing them so quickly.
However, that doesn't change the fact that the intersection that ATC are flying you towards are actually now defined as coordinates, not radials or distances from nearby VORs.
If an ATC tells you "direct OKSAW" they won't give you a VOR radial to intercept - you are expected to go straight there in a relatively straight line from your current position. There were boxes like the KNS80 that could do VOR-VOR navigation to do this kind of thing but it's not user friendly by modern standards.
When you file your flight plan, there is a box for "equipment". Put "O" there and they will not do that to you anymore. "DO" if you have DME.
This won't work in the UK/Europe. B-RNAV has been a requirement since 11 April 2011 at all ATS controlled routes and levels (previously only above FL95). The only reasonable equipment is a IFR capable panel mounted GPS.
Of course the UK is extra weird because you can fly IFR in class G airspace which is quite extensive outside of terminal areas. More realistically this is VFR in IMC, with the pilot being responsible for his own terrain and traffic separation (somewhere between relying on the "big sky" theory and these days, hopefully, some TCAS system). We even have a special sub-ICAO IR(R) rating which allows a pilot to punch holes in clouds and even to shoot an approach at a airport but not to access the class A TMAs / airways.
Oof...since 2011? Even with everyone knowing that GPS signals are -125 dBm on a good day and anyone can jam them? Jeez! My condolences. At least here stateside one can still fly IFR with a VOR/DME just fine.