We use a range of sources to track aircraft re-registrations.
Firstly we have our internal register tracking tools which have highlighted some aircraft moving between registers. Please note that whilst we do monitor the publicly available Russian register, they only tend to update every 2-3 months and we haven’t had a recent update. However, alongside that we have our internal tail tracking tools which are alerting us to new aircraft on Russian airline schedules, and there are a whole number of enthusiast / amateur forums that are monitoring HEX codes transmitted by these aircraft – we then do research to work out the tie up for the new registration. We are monitoring all these sources constantly in what is a very fluid situation.
With regard to tracking re-registrations, please refer to the attached screenshot that demonstrates a sample Fleets Analyzer search.