Complex sentence: By some sources it was equipped with Kuznetsov NK-12 outboard engines, and Kuznetsov NK-14 inboard nuclear powered engines, although its nuclear reactor did not help in the actual flight of the aircraft.
Split into simpler sentences: By some sources it was equipped with Kuznetsov NK-12 outboard engines, and Kuznetsov NK-14 inboard nuclear powered engines. Although its nuclear reactor did not help in the actual flight of the aircraft.