In this work we consider families of triples of matrices ϕ(ξ) = (E(ξ), A(ξ), B(ξ)) with the parameter vector ξ ∈ R k , representing families of generalized linear time invariant systems in the formarising naturally in a variety of circumstances for example they are used in modelling a three-link planar manipulator.We analyze the structure of the subset of parameters such that the corresponding triples are non-controllable for a oneinput generalized linear dynamical system. For n = 2, 3, explicit formulae describing this set are presented.