tartare,
My flights in a Yak-40 and Yak-42 were in consecutive years, immediately after the breakup of the USSR.
My first flight in the Yak-40 was from Usinsk to Ukhta in the Komi Republic in Arctic Russia, after arriving in Usinsk in a Canadian 727. I was part of a group going to visit a Canadian-British-Russian Oil Joint Venture. I remember being somewhat taken aback on arrival at Ukhta when the first time I saw the ground was over the threshold! There was no ILS so I assume we did a GCA.
At the end of our two-week trip, we were ferried to Moscow in another Yak-40, but this was a VIP version with plush seats, some couches and a fake wood interior. It was the personal aircraft of the chairman of the JV's Russian partner. One of our group had a NatGeo map of the USSR. The pilots were intrigued and asked to see it. They told us, through our translator, that they had never seen a map like this!
The following year, on a visit to another oil company, we flew from Moscow to Saratov on the Volga River, in an Aeroflot Yak-42 ( a Tridentski?).
I was quite taken aback when most of the passengers carried all their luggage on board. Suitcases were stacked in the aisles!
Our return journey was quite unpleasant. My seat mate was a large man, stinking of Vodka, who kept falling asleep, with his head on my shoulder. I kept pushing him off, to avoid him slobbering on me!
During our stay in Saratov, we were ferried by an Aeroflot Mi-18 to visit an oilfield.
Two things about this flight stick in my memory. One was how we were nearly blown over by the downwash as it came in to land to pick us up - 13 tonnes maximum AUW. The second was sitting sideways in foldable seats, looking at each other, across a large auxiliary fuel tank in the centre of the cabin!