Were civilian aircraft allowed to overfly the Soviet Union? The great-circle route from Western Europe to, say, Japan involves putting in a lot of miles above Russia, for example like this (London Heathrow&ndash;Tokyo Narita; map from gcmap.com).



Would routes like that have been possible during the days of the Soviet Union or would civilian planes have had to take a more circuitous route, flying south of the USSR and maybe even avoiding the Warsaw Pact countries, too?

I'm aware that at least some of Soviet airspace was prohibited which, for example, led to the Soviet Air Force shooting down Korean Air Lines flight&nbsp;007. Presumably, the route shown in the map would be prohibited, since it goes over the Kola Peninsula, where the Northern Fleet is based and Novaya Zemlya, a major nuclear weapons test site.
During the Cold War, Soviet airspace was very restricted to other countries. Flights from the US often had to follow polar routes to Asia and Europe that avoided entering Soviet airspace. The end of the Cold War allowed new routes to be used.


Source

Flights to the USSR were allowed on a limited basis, often in conjunction with service by Aeroflot. Air Canada had the first service (via Copenhagen) from North America in 1966. Some flights were allowed to cross the USSR (JAL started in 1985) but would often stop on Moscow. Otherwise, Anchorage was a typical stop on such a route. International relations may have improved since the Soviet era, but even today not every airline gets permission to overfly Russia.

The strict policies are the reason that flights such as Korean Air Lines flight 007 were shot down when deviating from these routes, and the flight of Mathias Rust to Moscow was a big deal.