The titular error of this film occurs when Kochin (N. Dodokhin) brings home plans for a new supersonic aircraft he's constructing. Unfortunately for him, his morally conflicted girlfriend (Lyubov Orlova) has been blackmailed by a foreign spy to help photograph the plans. As she is killed before she can confess her wrongdoing, it falls upon Kochin. However, the warmhearted NKVD secret police chief and his assistant track down the real criminals and clear Kochin's name. Engineer Kochin's Error features a script written in part by author Yuri Olesha, who was criticized for his literary decline under Stalinism.
~ Rebecca Flint Marx, All Movie Guide