The message you’ve posted suggests that the site isn’t down, but rather you’re being blocked from it for some reason.
So I tried accessing it, and yep, it loaded just fine for me.
It’s not down.
Followup: my phone uses a web service that obscures its location by default, and that’s what loaded the site.
Using my laptop (which does not do the same thing), I get the same message you do and then get redirected to the US/English version of the Aeroflot website after a moment.
Interesting.
So it seems they’re actively screening who has access to it, apparently on a geographic basis.