modest, possessing a great personality, equally brilliant in theory
as well as in technique, Pénaud was certainly one of the most
clairvoyants precursors in the dawn of aeronautics. Yet, Alphonse,
the son of admiral Pénaud, born in Paris in 1850 was planning
a naval career. It was a crippling illness that brought his creative
spirit to develop an interest in the difficult questions about
In April of 1870, Pénaud invented a mode of propulsion, perhaps
laughable today, but it was an invention that would provide a
mean of performing small experimentation for years to come: it
was the rubber band motor, built of twisted strands of elastic.
The first successful application was a scaled model helicopter.
Built of lightweight materials, this apparatus could climb up
to the ceiling, and sustain flight before returning to the ground.
Pénaud's obsession for perfection led him to have his apparatus
built by Breguet, a clockmaker and engineer. The propellers blades
made of paper were covered with gold platting to increase efficiency,
and the smaller parts were constructed with aluminum.
On August 18th 1871, he demonstrated that continuous flight was
not a fluke. His "Planophore", a scaled model airplane was capable
of achieving flights over a distance of 60 meters. It was a monoplane
fitted with a stabilizing tail section. The rubber band motor
drove either a tractor, or a pushing type propeller, depending
on the model type. The characteristics of his machines, would
remain for a long time those of future airplanes, and were truly
advanced for the era. The fundamental flight experiments of the
"Planophore" was demonstrated on many occasions, and endorsed
by the members of the newly formed Société
Française de Navigation Aérienne (French
society of aerial navigation). Pénaud continued to study the laws
of airplane longitudinal stability. To compensate for the effects
of propeller torque, he installed additional weight on one of
the wings. Later on, he resolved the torque problem with by twisting
the wing's airfoil (known today as wing wash in or wing washout).
Pénaud also developed other means of aerial locomotion, such as
his machine with flopping wings, and he would also return to machines
with rotating wings.
Not ignoring the work of his predecessors, he revived and published
the studies of Caley, another genius precursor. Between 1872 and
1875, he published numerous of his own studies concerning airflow
around the machine, air resistance (drag), and the characteristics
of gliding flight. We therefore owe Alphonse Pénaud the definition
of aviation's three basic problems: air resistance - machine strength
- and light weight engines. Going against the beliefs of the era
which favored steam engines, (i.e. Clément Ader), or electric
engines, Pénaud's faith in the all-new internal combustion engines
His main concern however, was to resolve the aerodynamics problems
of drag and weight.
Where Pénaud demonstrated the true correctness of his visions,
was in an airplane project which he developed in cooperation with
Paul Gauchot. Let's examine and evaluate the characteristics of
this machine for which an invention license was applied for and
accepted in 1876.
It was an amphibian monoplane, somewhat in the form of a flying
wing, propelled with two variable pitch tractor type propellers.
The wing's structure was planned to be built out of wood, or metal,
with a type of covering contributing to strength. Initially, the
first model's wing would have been equipped with struts, to be
replaced eventually with a stronger cantilever wing. And, speaking
of vision for the future: the machine was to be equipped with
a retractable landing gear, fitted with compressed air shock absorbers.
The fuselage was to be waterproof, wingtip floats, possibilities
of being launched by catapult, and way ahead of its time, a single
compensated control for pitch and directional control. Let's not
forget that the year was 1876, twenty-seven years before the historic
Kitty Hawk flight!
Let us also look at some of the details in Pénaud's invention:
Headrest aerodynamically shaped, windshield, relative wind indicator,
bank indicator, anemometer, electric control of the elevators,
and an indicator of air pressure on the wings. The list provided
on this 1876 invention registration goes on and on.
Alphonse Pénaud was not a typical businessman. Finding the necessary
capitals to finance his enterprise was way out of his reach and
depression soon began to ruin his health. He cut all ties with
the Aeronautical Society, and when he was refused further help
from anyone in 1880, he returned home and committed suicide.
A macabre detail: before ending his life at thirty years of age,
he enclosed all of his invention blueprints in a small coffin!
Years later, two young children in the USA were given a Pénaud
helicopter toy by their Father, and they would closely study its
characteristics. Their names:
Orville and Wilbur Wright!