While the Morane-Saulnier MS.406 struggled against the Luftwaffe in 1940, it found its true calling in the Finnish Air Force. Finland received 30 MS.406s from France during the Winter War, and they proved to be rugged and effective interceptors. Finnish pilots highly praised the aircraft’s maneuverability. Later, Finnish engineers famously modified the design by installing captured Soviet Klimov M-105 engines, creating the superior “Mörkö-Morane” (Ghost Morane). The MS.406 served with distinction throughout the Continuation War, claiming numerous victories against much more modern Soviet opposition.