The Kuznetsov NK-12 is a Soviet turboprop engine of the 1950s, designed by the Kuznetsov design bureau. It drives huge eight-bladed (four per propeller) contra-rotating propellers 5.6 m (18ft 4.5in) in diameter (6.2 m (20ft 4.1in) in the NK-12MA and NK-12MV).
Read more about Kuznetsov NK-12: Design and Development, Applications