What type of balloon did Pilâtre de Rozier attempt to fly across the English Channel?

Pilâtre de Rozier attempted to cross the English Channel in a Rozière balloon, a hybrid craft combining hot air and a lifting gas.

The design was named after Rozier, who proposed using separate chambers for heated air and hydrogen. Hot air could be controlled with a burner, while hydrogen supplied continuous buoyancy. In theory, this combination offered advantages over using either system alone.

Rozier’s 1785 aircraft contained hydrogen and hot air, but the experiment ended in disaster when the balloon caught fire near Wimereux. Rozier and Pierre Romain were killed, making the accident the first fatal aviation accident.

Modern Rozière balloons generally use helium rather than hydrogen because helium is non-flammable. The type has nevertheless retained Rozier’s name. It should not be confused with an ordinary hot-air balloon, which rises solely because air inside its envelope is heated.