Antonov Design Bureau and Volga Dnepr AN124 fleets currently provide the core of the world's bulk cargo airlift capacity.
Users include Boeing, Bombardier, Rolls Royce, UK Ministry of Defence, US Govt, United Nations plus a host of individual companies ranging from generator manufacturers to car race and rally teams.
Most flights are either one off or long term contract charters but some consolidated loads are flown when the opportunity arises.
Over the years, loads have included military hardware from most nations taking part in UN peacekeeping and military campaigns, aircraft engines, railway engines, large generators and power station parts, famine and refugee relief items, aircraft fuselages (including RAF Nimrods) - in fact both companies operate on a basis of "if we can lift it, we'll deliver it, anywhere in the world we can land the aircraft".
The crews are assigned to an aircraft and are very much self sufficient, operating like the tramp steamers of old. Some crews don't see home for months at a time and Seattle, Shannon, Toronto, Kabul, Sydney are as much "home" as Kiev or Ulyanovsk.
Volga Dnepr now has a base in Houston, geared to the oil industry.
Antonov Design Bureau AN124s are marketed ny Air Foyle/Heavylift (Heavylift having previously been joint operators with Volga Dnepr).
Here in the West of Ireland, it is not uncommon to see up to 5 124s on the ground at Shannon with 1 or 2 Volga Dnepr aircraft on maintenance, one on standby and a couple of others (Volga or ADB) calling for fuel.