Parachute valve hot air balloon. This causes the balloon to slow its ascent. Since the hottest air sits at the top this releases the balloons most buoyant air and increases the speed of descent. The balloon will descend at a faster rate than if it were allowed to cool naturally.
The parachute valve is an opening at the top of the balloon envelope. Using the parachute valve and the burners allows very accurate vertical control of an hot air balloon. The first untethered manned hot air balloon flight was performed by jean francois pilatre de rozier and francois laurent darlandes on november 21 1783 in paris france in a balloon created by the montgolfier brothers.
If the pilot keeps the valve open long enough the balloon will sink. The yellow circular section at the crown of the envelope is the parachute valve. This causes the balloon to slow its ascent.
When the pilot pulls the attached cord some hot air can escape from the envelope decreasing the inner air temperature. Parachutes have been used since from the end of the 18th century. Attached to a parachute valve at the very top of the balloon.
If the pilot keeps the valve open long enough the balloon will sink. This also causes the remaining air to begin gradually cooling and the balloon slowly sinks back toward earth. The parachute valve is a vent in the top of the envelope that allows some of the hot air to escape.
A parachute is meant for slowing down the speed while falling whereas a hot air balloon is meant for floating by propelling and maintaining a high altitude with the help of a burning gas. When closed it traps hot air from the burner inside the balloon making the hot air balloon rise. The hot air balloon is the first successful human carrying flight technology.
By pulling on ropes in the basket the valve can be opened and some hot air released.