Abstract: The dynamics of the airplane impacting on water was investigated. The arbitrary Lagrangian-Eulerian (ALE) method was employed to describe this fluid-structure interaction problem. The velocity of the airplane after landing was researched by analyzing the velocities of the airplane head and tail. The head and tail velocities changed rapidly in the initial stage of entering water, and then they kept stable. The structural response of the airplane airframe after landing was explored under different vertical velocities, horizontal velocities and landing elevations. The von Mises stress arrived at the peak value in the initial stage, then it decreased rapidly, finally it stayed steady. The maximal structural deformation was achieved in the hundreds milliseconds after landing, and then it relapsed rapidly. Comparison shows that the vertical velocities can affect the structural response of the airplane airframe the most strongly, the following are landing elevations, and the weakest are horizontal velocities.