which is the nearest major russian airport to Cheboksary that has cheap/regular flights to any london airport?

Answer 1

From the looks of it, I'd say Moscow (MOW) return flights for 250 to 350 pounds (cheapest one on Expedia was Allitalia)

Answer 2

I hope you aren't talking to a young Russian girl and have to arranged to meet her somewhere out of Russia. If you are you are being victimized. Cheboksary is one of the top cities where these scammers operate.
If you have been talking with her through e-mails, the chances are about 98% that you are being scammed.
Are you being sent photos? If you are, do this: Ask for a photo with the girl holding a sign with your name, date and some other word. If it is not forthcoming within 48 hours, get away fast!!!!!
More than likely, it is some guy who has found photos on some web site and is using them to scam you.
There have been thousands of men who have fallen prey to this and a few girls as well.

Do this: offer to go there to see her. I bet she will have all kinds of excuses as to why it is better for her to come see you.

Answer 3

Cheboksary itself have an airport (code CSY) with services provided by UTair Aviation (code P2). There are flights from there to Ekaterinburg (SVX) and Moscow (MOW) where you can catch direct flights to London (LON).
Your second option would be Kazan (KZN). There are no airlines providing direct services to London from there, but there are some airlines that can provide nice connecting services. They are:

Lufthansa (LH) through Frankfurt (FRA)
Turkish Airlines (TK) through Istanbul (IST)
Uzbekistan Airways (HY) through Tashkent (TAS)

Otherwise, the closest airport with direct services from London would be Moscow Domodedovo (DME) with services from London provided by British Airways (BA) and Transaero (UN).