A vol (French for "flight") is a once-obscure heraldic symbol consisting of a pair of outstretched, usually plumed bird's wings, which are connected together at their shoulders without having any bird's body in the middle.

All derivatives of this symbol in the twentieth century ultimately derive from its use by the French Armée de l'Air, one of the first Air forces in the world. A vol was selected for its cap badge, instead of the eagle which was selected by many of the world's other air forces. The reason why the French Air Force chose to differ is that the eagle in France is associated with the Napoleonic empire.

Read more about Vol:  Cap Badges, Insignia of Branch of Service, Pilot's Insigne, Rank Insigne, Collar Tab Insigne, Heraldic Use