The paper considers a characteristically loaded equation of a mixed hyperbolic-parabolic type with degeneration of order in the hyperbolicity part of the domain. In the hyperbolic part of the domain. we have a loaded one-velocity transport equation. known in mathematical biology as the Mac Kendrick Von Forester equation. https://www.lecoureures.shop/product-category/ski-de-fond-accessoires-piece-de-rechange/