I'm not a pilot or FE but worked in ground handling.. here are some memories of what I remember handling charters operated by Soviet bloc..this was ex-SIN back in the late eighties/early nineties.
"Normal' western charter crews will accept that a copy of the flights ppwk (eg load-sheet, flight-plan, fuel-chit, tech log etc') will remain on the ground to facilitate investigation in the event things dont go as planned.
For these soviet bloc aircraft you were often as not handed a piece of paper with some weights on it in lieu of a load-sheet and that was it. You could usually secure a copy of the ATIS flight plan locally and the passenger/cargo manifest for departure was available locally and that was it. Your station file for this flight was woefully thin compared to other flights!
These crews were usually well-stocked for trade and we usually bought a Casio or Seiko watch when we had one incoming as you could usually trade these for a russian camera or watch. The Russian watch was usually a Raketa or Vostok and the camera was a KNEB which I understand was Kiev. Vodka was available but this was difficult to get out of the airport. They usually had a bagful of those aluminum medals that you see all over Moscow on hand too. One guy used to buy them up and sell them to shop in Orchard Road (Lips), this was during the punk rock era and badges were 'in'. Another place you could find these was in Change Alley (SIN)
The freighters usually worked on 12hr layovers and the crews would stay with the plane. They would place drip pans under the engines and do some work on the donks. It was common to see them dismantling a component and 'overhauling' it. Similar to what I used to do with my bike!
They also were very lax when it came to smoking and drinking. You could usually see several bottles of liquor when the cleaners emptied the bins and smoking on board was common.
The Il-62's did not run any APU and the ground power could only run the ventilation system.. not air-conditioning. Cabin did not smell nice. Cabin attendants were frumpy.
Pushback usually took longer than other aircraft too... the aircraft would be pushed onto the taxiway.. then the holds need to be opened up, the towbar loaded and tied-down, doors closed and then only the thing taxied away. Freighters were usually allowed to park sideways but you needed to be sure that aircraft was not too far from the hydrant point (the airport I worked did not have any power-in/power-out bays).
Flight-planning was also basic in the extreme, they would just ask for the flight plan for the previous flight over the same routing (irrespective of carrier and a/c type) and based theirs accordingly, substituting lower levels and speeds if required. Lazy maybe but it works. Most of the flights I handled ex-SIN were headed home via BKK.
You would also see the crew walking over to the next aircraft and getting some info.. The company I worked for in SIN handled China Airlines, Flying Tigers/Fedex and Northwest Orient on the cargo ramp and there was no evidence of any ill-will. I don't know what they discussed but you could see there was no ill-feeling..and this was before the Iron Curtain fell.
I also went aboard a TU-134 operated by Hang Khong Viet Nam and I second Mr Oleo Strut's comment about the similarities with Victorian Drawing rooms. Heavy dark panelling and plush seats. The first row faced rearwards.
Also remember a Hang Khong Viet Nam IL-18 combi. Passengers were carried in the tail end with the cargo all loaded in the middle. From the looks of the passenger cabin it has done its share of cargo hauling as well! Two cabin crew were on board and they looked really stunning in their Ao Dai's, really out of place in the sad passenger cabin.
Finally, for all the charters operated by Soviet bloc countries which I have attended, not one of them was ever grounded. There were times where there was a lot of discussion and cowl-opening etc but they always departed. Even though all the aircraft departed, I believe not one of them departed on time !
Anil