The paper is concerned with the following n × n Dirac type equationWe show the existence of triangular transformation operators for such equation under additional uniform separation conditions on the entries of the matrix function B. Here we apply this result to study direct spectral properties of the boundary value problem (BVP) associated with the above equation subject to the general boundary conditions U(y) = Cy(0) + Dy(ℓ) = 0, rank(C D) = n.As a first application of this result, we show that the deviation of the characteristic determinants of this BVP and the unperturbed BVP (with Q = 0) is a Fourier transform of some summable function explicitly expressed via kernels of the transformation operators. In turn, this representation yields asymptotic behavior of the spectrum in the case of regular boundary conditions. Namely, λ m = λ 0 m + o(1) as m → ∞, where {λ m } m∈Z and {λ 0 m } m∈Z are sequences of eigenvalues of perturbed and unperturbed (Q = 0) BVP, respectively.Further, we prove that the system of root vectors of the above BVP constitutes a Riesz basis in a certain weighted L 2 -space, provided that the boundary conditions are strictly regular. Along the way, we also establish completeness, uniform minimality and asymptotic behavior of root vectors.The main results are applied to establish asymptotic behavior of eigenvalues and eigenvectors, and the Riesz basis property for the dynamic generator of spatially non-homogenous damped Timoshenko beam model. We also found a new case when eigenvalues have an explicit asymptotic, which to the best of our knowledge is new even in the case of constant parameters of the model.