Aircraft structural dynamic and aeroelastic analyses are performed using sophisticated Finite Element (FE) models. The modeling of mass properties is a key milestone in building these dynamic FE models. This paper performs a comparative analysis of different mass modeling strategies, according with the different type of masses of an aircraft: Operational Empty Weight (OWE), payload, fuel, external pods, etc. For this exercise, the dynamic FE model of the future heavy military transport aircraft A400M will be used. The different modeling strategies have a significant impact on the results obtained with these models from the structural dynamics and aeroelasticity standpoint. The paper will show the effect on: Normal mode frequencies and mode shapes; Dynamic loads resultant from a severe 12 fps sink speed landing. The paper will address the different options and will propose the most suitable strategies to obtain the best results from the aeroelastics and structural dynamics point of view. The paper ends with lessons learned and proposals for future developments.