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Aircraft buoyancy is an important consideration in safe aircraft design. FAR 25.801 requires that in the event of emergency water landings, an aircraft must float long enough for passengers and crew to escape and board life rafts.

Current methods do not include any analysis of stability, and each solution must be developed for an exclusive aircraft and configuration.

To demonstrate compliance with this regulation, this study describes an improved method using a dynamic computer simulation developed with Simcenter Amesim that models the aircraft's position, orientation, weight, center of gravity, and center of buoyancy during a water landing. Internal geometry is modeled at points where water can leak into the plane as air tanks with variable flow rate orifices, allowing a simulation to show the change in buoyancy characteristics as water leaks into the aircraft and predict how much time passengers and crew will have for safe egress.

This method improves upon past methods, allowing for a wider range of testing. Physical validation is beyond the scope of this study.

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