I tried http://rasp.yandex.ru (http://Yandex.Timetables), probably the most comprehensive search engine for transport in Russia, and it shows that 5N 799 flyes on Mondays, Wednesdays and Fridays (including August), departing from Arkhangelsk at 10-50am.

The Arkhangelsk airport site is showing today's flight to Murmansk/Tromso as "departed" which strongly suggests it does exist, it is not just a figment of the imagination

Thanks very much for your replies.

I'd seen the schedule for 5N 799 which showed flights for August, but yesterday I couldn't get the Nordavia system to find any flights on which I could book a ticket, whether for August or for next week. I had tried last month and had been able to book tickets for flights three months ahead, but no further - so I thought that there was some kind of weird three-month restriction on bookings (that's when I sent Nordavia an enquiry about booking ahead). However, yesterday, I couldn't get the system to find flights for any dates - as Marassa said, it probably was not working properly.

Interestingly, I tried again this morning on the Nordavia site and I could do a dummy booking for flights up to the end of May - but not for any time beyond that.

I tried the tutu.ru site but it only showed indirect flights via Moscow for our date - we're hoping to do the direct flight if we can so that we don't have to backtrack (and it does seem to exist!).

I suppose that I'll just have to keep trying the website at random occasions and hope that it works - or change our itinerary.

Thanks again for your help!