British Airways Boeing 777-336ER G-STBH operating BA7 London Heathrow – Tokyo Haneda was delayed entering Russian airspace due to a flight plan issue and made a loop over Joensuu in Finland. The aircraft then entered Russian airspace and flew for two and a half hours when it turned back close to Sidorovsk due, we understand, to the new flight path being too long to reach Tokyo without refuelling and the failure to find a suitable fuel stop within Russia. The initial plan was to refuel at Helsinki but crew would not then have had sufficient hours to reach Tokyo and so the decision was made to return to London Heathrow.