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.
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
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.
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.
Vectoring by the controller to a visual or ILS approach still works but they'd be juggling a lot of planes. And while lots of the bigger/older airports still have ILS, many VORs and DMEs are being retired and many smaller airports don't have ILS at all.
Denied access to GPS in a large area in bad weather would likely result in lots of flight cancellations and contingency plans getting put in motion to get anything still in the air landed safely. But controllers would get very busy and ILS runways very congested.
Here in Europe, there have been a few cases of GPS denied areas especially closer to Russia. Mostly pilots and controllers at e.g. Helsinki airport are able to deal with this.
But yeah, IFR is getting more dependent on gps approaches…
which is incredibly stupid because it becomes trivial to disrupt air navigation. It’s a bit better with newer chipsets that support GPS, Galileo, GLONASS, and BeiDou… but I’d venture that when the military is jamming I’d does them all. I can buy a jammer that will take out GPS over about a kilometer for less than $1k. They are used all over the place by criminals in many countries, because there often aren’t standardized addresses and if your drug house can’t be located on gps in the favella, you get a lot more warning before a raid. That same transmitter with a directional antenna could knock out a 10 degree sector for 30km.
VMC prevailed at the time of the accident, although it was a dark moonless night. The flight in question only needed to maintain an altitude above the mountains until a visual to the airport was established along with their distance from the runway.
My guess based on the flight path is they had a visual on the airport but were lost and didn’t know where they were. If the gps hadn’t come back on for a minute they probably would have been fine, but it came back on and they fixated on the shiny screen instead of using their navigation skills.
Unless you want trust your life to an instrument, you fly like it might not be trustworthy. Granted, there are many instruments in an airplane we trust our lives to, but they can mostly be cross-referenced against other inputs. The trouble with gps is that it enables procedures that make that essentially impossible, and the major failure mode is not one you can carry an extra for. In aviation, situational awareness is life.
Pilots were so used to "the plane won't make a mistake" that they were not aware/not trained properly about things that are nothing to do with the FMS like frozen pitot tubes and also that the autopilot has a number of "modes" which mean you need to go back to basics like altitude, attitude and air speed.
Of course there have also been crashes where pilots wrongly dismissed sensor data.
In the Kegworth air disaster [1] the pilots had sensor data telling them the left-hand engine was at fault - but a previous model of the plane had a reputation for unreliability in that sensor, and the pilots shut down the right-hand engine on the basis of other evidence.
So we don't want pilots blindly trusting broken sensors - but we also don't want them to dismiss working sensors as broken.
[1] https://www.faa.gov/lessons_learned/transport_airplane/accid...
If it isn’t true, then the military is partially responsible for the crash of this aircraft.
VOR Candidate Retention List | Federal Aviation Administration https://www.faa.gov/ato/navigation-programs/vor-retention-li...
> The VOR MON program is designed to enable aircraft, having lost GPS service, to revert to conventional navigation procedures. This will allow users to continue through the outage area using VOR station-to-station navigation or to proceed to a MON airport where an Instrument Landing System (ILS), Localizer (LOC) or VOR approach procedure can be flown without the necessity of GPS, Distance Measuring Equipment (DME), Automatic Direction Finder (ADF), or surveillance. Any airport with a suitable instrument approach may be used for landing, but the VOR MON assures that at least one airport will be within 100 Nautical Miles (NM).
* https://www.faa.gov/about/office_org/headquarters_offices/at...
2011:
* https://www.federalregister.gov/documents/2011/12/15/2011-31...
Is climate change going to make it more difficult to see outside?
Yes, the change we are undergoing and that the current administration seems to be doing their best to accelerate includes an increase in heavy precipitation across north america.