This study evaluates the potential danger of hail impacts on stiffened composite aircraft structures. Test specimen are created using Carbon Fiber Reinforced Polymer (CFRP) with and without an Aluminium longitudinal stringer. These specimen are first indented to explore the effect and behaviour of stiffening elements and varying boundary conditions. Then an impact gun is used to impact the specimen with ice balls, simulating hail impacts in order to assess the potential danger of hail stones impacting the stiffened structure. It is concluded that the critical locations for damage formation are where deformations are most suppressed, such as the stringers and ribs of the aircraft. In these locations more damage at the same energy levels as well as a lower threshold energy level for damage initiation is observed. Additionally, it is shown that repeated impacts in close proximity of each other, such as during hailstorms, can increase the resulting damage compared to separate single impacts. Ice impacts demonstrate only a fraction of the kinetic energy is absorbed during an impact, but large hailstones occurring during rare hailstorms can definitely cause serious damage in the critical locations in aircraft. So, for future research, testing and certifying the potential of hail impacts must be recognised and determined in the critical stiffened locations within an aircraft