We propose a large time-step and asymptotic-preserving scheme for the gas dynamics equations with external forces and friction terms.By asymptotic-preserving,we mean that the numerical scheme is able to reproduce at the discrete level the parabolic-type asymptotic behaviour satisfied by the continuous equations.By large time-step,we mean that the scheme is stable under a CFL stability condition driven by the(slow)material waves,and not by the(fast)acoustic waves as it is customary in Godunov-type schemes.Numerical evidences are proposed and show a gain of several orders of magnitude in both accuracy and efficiency.If time permits,an extension of the method to low-Mach number regimes will be discussed.