  The flow taking place in the rear part of the fuselage during the emergency
landing on water is investigated experimentally in realistic conditions. To
this aim, tests on a double curvature specimen have been performed at
horizontal velocities ranging from 21 m/s to 45 m/s. Tests data highlight
different cavitation and/or ventilation modalities which are highly dependent
on the horizontal velocity, with substantial variations in the flow features
occurring with velocity variations of few meters per second. For the specimen
considered here, the inception of the cavitation is found at about 30 m/s,
confirming that scaled model tests performed at small horizontal velocities are
unable to capture the hydrodynamics correctly. By comparing pressure data,
underwater movies and force measurements, it is shown that the transition from
cavitation to ventilation condition has a significant effect of the
longitudinal distribution of the loading which, together with inertia,
aerodynamic loads and engine thrust, governs the aircraft dynamics.
