Abstract: The invention is a ballonet system for a lighter-than-air-vehicle, the vehicle having a lift producing gas bag and a longitudinal, vertical and lateral axis. In detail, the ballonet system includes a plurality of ballonets located within the gas bag positioned along the longitudinal axis and on each side of the vertical axis of the vehicle. Each of the ballonets include a flexible sheet joined at its periphery thereof to a portion of the wall of the gas bag. A ballonet pressurization system is coupled to each ballonet for pressurizing them with air that includes the portion of the wall of the gas bag forming the ballonet having a plurality of holes therethrough. A manifold having an inlet port is joined to the wall covering the holes therein and is adapted to diffuse the pressurized air entering therein.