Computing electromagnetic scattering and radar cross section for electrically large objects like aircraft presents major computational challenges. This whitepaper compares numerical methods for efficiently simulating RCS of large aerospace structures: Method of Moments (full-wave), Extrapolated MoM, Physical Optics, and hybrid techniques. Simulations of a 40-meter civilian transport aircraft at 0.5-1.0 GHz demonstrate that approximative methods achieve accuracy comparable to full-wave…