It appears that the Russian Republic refrains from registering "western build" airplanes with its national RA-xxxxx type registry. I do not know the status of VP-BKO, which is probably leased by Aeroflot.
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By the way, Aeroflot North is not a subsidiary... It is a "directorate" of Aeroflot, as Aeroflot domestic structure consists of separate regional "directorates" which are based in various Russian cities.
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A few years ago (2005) I ferried as captain, the first 4 "TransAero" 747-200s from USA storage to Moscow Domodedovo. These airplanes were ferried (and now operate) with a Bermuda registry VP-Bxx, and their status is "leased" to TransAero, a Russian charter airline.
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Happy contrails