Abstract
The Japanese ocean area of about 4,470,000km^2 is the sixth in the world. Therefore, it is newly necessary to establish an appropriate transportation other than a ship to utilize the Japanese ocean effectively. In addition ultra light seaplanes are attracting attention recently from the viewpoint of natural environmental protection. Accordingly the JRPS is now developing FRP float for these planes. In this paper, we simulate the behavior at landing of the seaplane by using the Smoothed Particle Hydrodynamics (SPH) method which is one of the functions in PAM-CRASH and are able to show the tendency of the vertical acceleration change in the float part for the first step in deriving a crash force from analytical data.