Also changes in the status-quo of international politics: Russia has been chronically sabotaging non-Russian navigation systems in neighboring countries, beaming jamming and spoofing signals across the borders.
Russian airplanes aren't affected because nobody has chosen to retaliate in kind... Yet.
Planes have inertial measurement units which are the primary source. GPS or GNSS are just backups. You can switch these off with zero consequence during the flight. It may cause your satellite TV and internet to stop working but no critical systems will be impacted.
Russian airplanes are commercially purchased from the same sources as the rest of the world and are generally outfitted with identical equipment.
The impacts to flights has to do with certain types of GPS coordinated instrument approaches for landings. Most of these runways have alternative approach strategies that can be used during jamming or other unavailability.
There is no need to jam GLONASS. Russian planes are affected using other means--sanctions have cut them off from access to parts and maintenance. It's more impactful because all planes are affected by this, not just those that fly near the border of NATO countries.
I feel like that is mixing separate issues. The sanctions aren't because of the jamming and spoofing. If some other country started foisting the same pollution/sabotage onto its neighbors, those neighbors would still have a problem deciding on how to respond.
The main point is that the bar for someone breaking your navigation system has been lowered. It's not just something you'd expect in a small area or for a short time around an imminent violent confrontation, chronic disruption in a peaceful country is now A Thing That Happens.
That, in turn, changes the engineering considerations for how robust a product needs to be.
The bar has been crossed. Finland and other airlines flying in Northern Europe are suffering from GPS disruptions that make landing at smaller less-equipped airports impossible:
Russians definitely increased their jamming activity after sanctions were imposed. The point I was making is that you do not need to make operation of Russian airplanes more difficult by jamming GPS/GLONASS signals, it is sufficient to deny access to maintenance and parts.
> The point I was making is that you do not need to make operation of Russian airplanes more difficult
I'm saying that "make flights difficult" is kinda-besides-the-point. The real goal is to impose some kind of return-pain to make the offender stop. Poetic symmetry is merely an ideal bonus.
In other words, it may be true that "the ideal retaliation is not very effective because of other circumstances", however that is not the same as "there is no need to retaliate at all."
