Le Prieur rocket

The Le Prieur rocket was essentially a cardboard tube filled with 200 grams of black powder with a wooden conical head attached (by doped paper or linen tape) and had a triangular knife blade inserted in a slot across its apex forming a spear point.

As top French military officers had expressed concerns about a fire hazard for the attacking aircraft, Yves Le Prieur first experimented with his weapon by fitting one on a short section of a Voisin aircraft wing bolted on a Piccard Pictet (Pic-Pic) automobile (one of the few period cars with a genuine 120-kilometre-per-hour (75 mph) capability).

Attacks were made in the direction of the length of the balloon and against the wind, the pilot taking aim via the plane's existing gun-sight.

In their first operational deployment, eight aces including Nungesser, Guiguet and Chaput were specially trained by Le Prieur in their use, and in an early morning attack on 22 May 1916 while flying Nieuport 16, managed to down six balloons in short order, panicking the Germans into lowering the remainder along 100 km (62 mi) of the front lines, blinding the German Army for the first French counter-attack on Fort Douaumont.

[4] Users of the rockets included France, United Kingdom, Belgium and to a lesser extent, Germany.