Alphonse Penaud (1850 – 1880) only began his focus on aeronautics after a crippling illness that stopped him from pursuing a career in the navy.

His work began in April 1870 when he invented a mode of propulsion using a rubber band motor which he made from twisted bands of elastic. Using this motor, he built a model helicopter which successfully climbed towards the ceiling in a sustained manner before returning the ground.

His quest for building high quality models led to him having the clock maker and engineer Breguet making the models for him. This led to the paper propeller blades being covered with gold plating to increase the efficiency of the blades. He also had the smaller parts made from aluminum.

On August 18, 1871, he was able to demonstrate his Planophore at Tuileries Gardens in Paris, France. This led to a flight of over 60 meters (181 feet) in 11 seconds. This model was fitted with a stabilizing tail section, later to be called the “Penaud Tail”. After numerous demonstrations the model was endorsed by the newly formed Société Française de Navigation Aérienne (French Society of Aerial Navigation).

The characteristics of the model would remain in place for many years to come.

From there Penaud continued to study the laws of airplane longitudinal stability. This led to the addition of weights to one of the wings to compensate for the propeller torque. In time, he resolved the problem by twisting the wing’s airfoil (known today as wing wash in or wing wash out).

Penaud also revived and worked from the earlier studies of Caley.

Between 1872 and 1875 he published many of his own articles about the airflow around the machine, air resistance and the characteristics of gliding flight. From this work the three problems of aviation were determined: air resistance, machine strength and light weight engines.

He went against the current beliefs that steam engines or electric engines were the way forward for powered flight, instead opting for the newly developed internal combustion engine. He felt the biggest obstacle was the aerodynamic problems of drag and weight.

In 1876, Penaud began working with Paul Gauchot on a large amphibious monoplane.

This machine was well ahead of its time. The list of additions includes: retractable landing gear, waterproof fuselage, wingtip floats, an indicator showing air pressure on the wing, windshield, relative wind indicator, anemometer, and the list goes on for this 1876 invention registration.

Unfortunately, Penaud and Gauchot failed to attract enough money to have the machine built. Penaud became so despondent when he realized a full sized machine would not be funded that he ceased contact with the Aeronautical Society.

In 1880 he went home and committed suicide, but before doing so he enclosed his invention blueprints into a small coffin.

Years later, the blueprints were used to make a toy helicopter for two boys going by the name of Orville and Wilbur Wright.