Installation noise caused by the interaction between jet flow and structures like wings or flaps has become a significant concern for commercial aircraft manufacturers, particularly due to the emergence of pronounced tonal peaks in the acoustic spectrum. To better understand this phenomenon, we developed a global stability analysis tool that combines the compressible nonlinear solver dNami with the source transformation automatic differentiation tool Tapenade. The analysis involves solving the unsteady Reynolds-averaged Navier-Stokes (URANS) equations using the Spalart-Allmaras turbulence model. A 2D global stability analysis at high Reynolds numbers will be presented and the results will be compared with experimental data obtained from wind tunnel by CNRS-PPrime laboratory.