Direct Numerical Simulations (DNS) were carried out to investigate the laminar-turbulent transition for blunt (right) cones (7◦ half-angle) at zero angle of attack. Two cases with different Reynolds numbers based on the nose radius were investigated. Linear stability calculations were carried out employing a high-order compressible Navier-Stokes solver and using very small disturbance amplitudes in order to capture the linear (primary) instability characteristics. The results of the linear stability calculations were then used to determine which nonlinear mechanism may likely be relevant and to choose the forcing parameters (frequency and azimuthal wavenumber) for "controlled" transition simulations that may lead to the transition. In order to determine if the disturbance waves identified from the linear calculations may indeed be able to trigger nonlinear breakdown, the disturbances were introduced in the entropy layer at high amplitudes.