The TV series "Les Chevaliers du Ciel" is based upon a series of comics "Les Aventures de Tanguy et Laverdure", that's probably why these two names are mentioned in the credit titles: "Dans la série 'Les Aventures de Tanguy et Laverdure'... Les Chevaliers du Ciel..." (In 'The Adventures of Tanguy and Laverdure' series... The Sky Knights...").