Louis
Charles Breguet


Louis Charles
Breguet
French Aviation Pioneer
Engineer and Industrialist
Place of Birth: Paris, France
Date of Birth: January 2, 1880
Date of Death: May 5, 1955
Louis Charles Breguet developed an early interest in aviation
technology. He developed a wind tunnel in 1905 which would measure
and evaluate the effects of airflow on airfoils. He a pioneer
aircraft designer who understood the need for pre-flight
experimentation and testing.
His first aircraft was a rugged biplane produced in 1909. This
aircraft set speed records, and standards of quality accepted in the
aviation industry.
Breguet was very successful during World War I. The company
produced over 8000 Breguet XIV reconnaissance aircraft for the
Allied Forces. The Breguet XIX made history in the postwar years as
a long distance aircraft capable of flying across oceans and
continents.
In 1919, Louis Breguet established a commercial air
transportation company, Compagnie Des Messageries Avienne, now named
Air France.
Unlike the airplane, the helicopter had a long and
trouble-plagued development. Whereas the Wright brothers get most of the
credit for developing the airplane, many more people, on several
continents, contributed to the development of the helicopter.
The biggest problem with the various early helicopter designs produced by
Louis and Jacques Bréguet, Igor Sikorsky, Juan de la Cierva, and others
was that although they could lift off the ground, they could not be
controlled in flight. Inventors did not understand the aeronautical forces
facing the helicopter and did not know how to design mechanical devices to
address these forces.
To control a helicopter, inventors had to devise a means of directing the
downward thrust of the rotors slightly off-center so the craft would move
in the opposite direction. They also had to find a way to overcome the
twisting motion, or torque, induced by the heavy turning rotor blades.
By the early 1930s, Louis Bréguet, one of the pioneers of helicopter
development, began to think about helicopters again, establishing the
Syndicate for Gyroplane Studies and hiring a young engineer named Rene
Dorand. Bréguet took a far more cautious approach than he had more than a
decade before. He oversaw the building of a helicopter that attempted to
solve the problems of stability and control. He cautiously named this
aircraft the Gyroplane-Laboratoire, clearly identifying it as an
experimental aircraft.
To make the most of a limited budget, Dorand built the craft as much as
possible from available bits and pieces. He used a Bréguet 19 airplane
fuselage for the craft's body and a surplus aircraft engine to power it.
The craft consisted of a thin metallic frame with a tail and three
wheels—one on either side mounted on outriggers and a smaller one at the
front of the aircraft. The engine was located forward, and the pilot sat
behind it in an open cage. Two twin-bladed rotors, each nearly 54 feet
(16.5 meters) long, were stacked coaxially on top of each other, rotating
in opposite directions and thereby canceling out their torque. The rotor
blades were attached to the shaft with a hinge mechanism (they were
"articulated"), and the pitch of the rotor could be increased or decreased
on each revolution (cyclic pitch control), thereby controlling lift. If
the propellers were angled so they pushed the air down more, lift would
increase, and the craft would rise.
Bréguet had confidence in his machine despite warnings from his mechanics
that the controls were not yet perfected. In November 1933, he scheduled a
demonstration flight for his investors. A former French Army pilot named
Maurice Claisse reluctantly agreed to make the test. He climbed into the
craft and started the engine as three men stood by on the ground to hold
the machine. The rotors turned and the craft immediately tilted to the
right. As bystanders—including the ground-handlers—ran for cover, the
rotor blades hit the ground and shattered. Fortunately, no one was hurt,
but the aircraft was badly damaged, postponing any further tests.
Throughout 1934 and 1935, Bréguet extensively modified his craft and
performed ground tests. His most important addition was a new system for
controlling the direction of flight. By tilting the axle on which the
rotors turned, pitching the rotor disk, the helicopter could be made to
move forward, sideways, or even backward. He added a system for
controlling the yaw of the helicopter (turning the helicopter to the left
or right) by allowing the two rotors to each have a different pitch
(differential collective pitch).
On June 26, 1935, test pilot Maurice Claisse hopped in the craft again.
This time he was able to lift it off the ground without crashing. He then
made several flights at speeds of 18 to 30 miles per hour (29 to 48
kilometers per hour). The French Air Ministry was so impressed it gave
Bréguet a contract that covered the cost of flight trials and provided a
million-franc-bonus if all performance goals were achieved.
By December 1935, Bréguet began the series of test flights. He then
proceeded to push his aircraft far beyond the limits of any previous
rotary aircraft. He was not always successful. Occasionally the rotors
collided with each other (a problem that still exists today on helicopters
with a similar design) upon landing or the rivets popped out. But Bréguet
repaired the craft in time for each new test flight. The craft achieved a
record speed of 75 miles per hour (121 kilometers per hour) and climbed to
a record altitude of 518 feet (158 meters), remaining in the air for more
than an hour. It stayed in a hover over one spot for ten minutes—also a
record. Bréguet completed his initial tests in late 1936 and received the
one-million-franc bonus.
Bréguet received another Air Ministry contract for further development but
made little progress over the next several years. One big concern about
helicopters was what would happen if the engine failed in flight. An
airplane could glide to the ground, but a helicopter needed to descend
while "autorotating," essentially using the rotor as a parachute.
Bréguet's aircraft was badly damaged during an autorotation test in 1939.
With war imminent, Bréguet put his craft in storage and turned his
attention to the full-scale production of bombers. His helicopter was
ultimately destroyed in 1943 during the Allied bombing of the Villacoublay
Airfield.
The stacked rotors that Bréguet used for his Gyroplane was not a popular
design in the West. However, it was used by the Soviet designer Kamov for
a number of anti-submarine helicopters such as the Ka-25 Hormone and the
Ka-27 Helix, as well as the attack helicopter known as the Ka-50 Werewolf.
Although Bréguet's aircraft was capable of lifting off the ground, it was
too heavy for long flights. It also had limited maneuverability. Many
aviation experts consider Bréguet's aircraft to be the first completely
successful helicopter. But it was soon upstaged by a more impressive
German craft, the Fa 61.
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