The world's largest Mi-26 transport helicopters utilized by the Russian army could shortly be grounded. The arrest by the SBU of Vyacheslav Boguslayev, erstwhile head of Motor Sich plants, and the breakdown of its grid has deprived Russia of the supply of D-136 engines. Their only maker is the Zaporizhia plant, and a Russian replacement... could go into production in 2025 if the prototype can be completed. Work on it has been ongoing since 2016.