The envelope contained a single ballonet for regulating the pressure of the gas.    From Wordnik.com.  [British Airships, Past, Present, and Future] Reference

The remote-controlled AirJelly is kept in the air by its helium-filled ballonet.    From Wordnik.com.  [tingilinde:] Reference

The wind blowing against the opening, which faces it, charges the ballonet with air.    From Wordnik.com.  [Aeroplanes and Dirigibles of War] Reference

Two automatic air valves are fitted to the underside of the envelope, one for each ballonet.    From Wordnik.com.  [British Airships, Past, Present, and Future] Reference

Six valves in all are used, four air valves, one fitted to each ballonet, and two gas valves.    From Wordnik.com.  [British Airships, Past, Present, and Future] Reference

It appears to be rearing up on end, as if the extremity saddled with the ballonet were weighted.    From Wordnik.com.  [Aeroplanes and Dirigibles of War] Reference

One ballonet was contained in the envelope which, at first, had three inflated fins to act as stabilizers.    From Wordnik.com.  [British Airships, Past, Present, and Future] Reference

And the chamber inside the envelope that expands and contracts to compensate for changes in helium pressure is called a ballonet.    From Wordnik.com.  [USATODAY.com - Rare air above the Super Bowl] Reference

The gas-bag comprises a single chamber for the inflating agent, the distended shape of the envelope being sustained by means of an air-ballonet.    From Wordnik.com.  [Aeroplanes and Dirigibles of War] Reference

If ascent is required, the after-ballonet is inflated, thereby driving the gas to the forward end of the balloon, the buoyancy of which is thus increased.    From Wordnik.com.  [Aeroplanes and Dirigibles of War] Reference

If it is desired to descend the gas is driven from the forward to the after end of the envelope, merely by inflating the bow ballonet with air by means of a pump placed in the car.    From Wordnik.com.  [Aeroplanes and Dirigibles of War] Reference

It was cylindrical in form with conical ends, and is of interest because a small balloon or ballonet, 7,050 cubic feet contents, was placed inside the larger one for an air filling.    From Wordnik.com.  [British Airships, Past, Present, and Future] Reference

On making a second ascent, as the airship rises the air must be let out of the ballonet instead of gas from the envelope, and by the time 1,000 feet is reached the ballonets will be empty.    From Wordnik.com.  [British Airships, Past, Present, and Future] Reference

The supply of air for filling these is taken from the propeller draught by a slanting aluminium tube to the underside of the envelope, where it meets a longitudinal fabric hose which connects the two ballonet air inlets.    From Wordnik.com.  [British Airships, Past, Present, and Future] Reference

He may thus be said to have invented the ballonet, or air-chamber of the balloon, and to be the father of later successful airships.    From Wordnik.com.  [The War in the Air; Vol. 1 The Part played in the Great War by the Royal Air Force] Reference

The Airjelly gracefully floats in the air thanks to a helium-filled ballonet, a central electric drive and an intelligent, adaptive mechanical system.    From Wordnik.com.  [doggdot.us] Reference

Santos Dumont was the internal ballonet, inflated automatically by a ventilator, the expedient being designed to preserve the shape of the main balloon itself while meeting the wind.    From Wordnik.com.  [The Dominion of the Air; the story of aerial navigation] Reference

Two automatic air valves, one for each ballonet, are fitted in the underside of the envelope, and, as the air pressure tends to open these instead of keeping them shut, the spring of the valve is set inside the envelope.    From Wordnik.com.  [A History of Aeronautics] Reference

In the kite balloon, the ballonet serves the purpose of a rudder, filling itself through the opening being kept pointed toward the wind -- there is an ingenious type of air scoop with non-return valve which assures perfect inflation.    From Wordnik.com.  [A History of Aeronautics] Reference

The ballonet became particularly valuable as soon as airship construction became general, and it was in the course of advance in Astra Torres design that the project was introduced of using the ballonets in order to give inclination from the horizontal.    From Wordnik.com.  [A History of Aeronautics] Reference

In the S.S. type of airship, two ballonets are provided, the supply of air being taken from the propeller draught by a slanting aluminium tube to the underside of the envelope, where it meets a longitudinal fabric hose which connects the two ballonet air inlets.    From Wordnik.com.  [A History of Aeronautics] Reference

This attachment serves the purpose of a ballonet.    From Wordnik.com.  [Aeroplanes and Dirigibles of War] Reference