François Denhaut (1877–1952) was a French
aviator
An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators because they a ...
notable for designing, constructing and flying the first
flying boat
A flying boat is a type of seaplane with a hull, allowing it to land on water. It differs from a floatplane in having a fuselage that is purpose-designed for flotation, while floatplanes rely on fuselage-mounted floats for buoyancy.
Though ...
in 1912.
[Nicolaou, p.17]
Life
He was born on 4 October 1877 at
Champagnat,
Creuse
Creuse (; or ) is a department in central France named after the river Creuse. After Lozère, it is the second least populated department in France. It is bordered by Indre and Cher to the north, Allier and Puy-de-Dôme to the east, Cor ...
and after some success as a racing cyclist became interested in aviation. In 1908 he constructed his first aircraft, a canard biplane powered by a Anzani.
engine constructed with the help of a mechanic called Bouyer a M. Mercier. It was briefly flown in August 1909, with Bouyer at the controls,
In 1911 he gained his pilot's license and became the chief pilot of
Pierre Levasseur's flying school.

He died at
Bellegarde-en-Marche in 1952. An Air Memorial is dedicated to him in Bellegarde, at the
Maison Chevanne, a 17th-century house that is also the village's tourism office and library.
Aircraft
1910 monoplane
1911 Model
In 1911 Denhault conceived the idea of the
flying boat
A flying boat is a type of seaplane with a hull, allowing it to land on water. It differs from a floatplane in having a fuselage that is purpose-designed for flotation, while floatplanes rely on fuselage-mounted floats for buoyancy.
Though ...
, an aircraft whose fuselage formed the main float of the aircraft. Previous aircraft intended to fly from water had all used an arrangement of floats mounted below the aircraft in place of wheels. The hull was triangular in
cross section, with the apex at the top. To provide hydrodynamic lift, the hull was fitted with an angled plate mounted below the nose. It was powered by a
Gnome Omega
The Gnome 7 Omega (commonly called the Gnome 50 hp) is a French seven-cylinder, air-cooled aero engine produced by Gnome et Rhône. It was shown at the Paris Aero Salon held in December 1908 and was first flown in 1909. It was the world's ...
driving a
pusher propeller mounted below the upper wing. To allow for maneuvering on the ground, an undercarriage was fitted, with two wheels attached.
[Parrochia p.131] Denhaut took particular advantage of this aspect of the design by taking off from the ground when he made the initial tests. This project was financed by Jacques Donnet, and the craft was later named after him.
The first proper test of the craft took place on 12 March 1912. Denhaut took off and flew over the
River Seine
The Seine ( , ) is a river in northern France. Its drainage basin is in the Paris Basin (a geological relative lowland) covering most of northern France. It rises at Source-Seine, northwest of Dijon in northeastern France in the Langres p ...
. However, when preparing to land, misjudged his approach, the nose-mounted hydroplane dug in, and the aircraft turned over; Denhaut managed to escape from the submerged
cockpit, and took refuge on the bottom of the upturned hull. The craft was towed back to shore.
[Noetinger, p.323]
1912 modifications
Denhaut, with the advice of
Robert Duhamel, decided to rebuild the aircraft, making the necessary modifications to the first design model. He changed the hull to be rectangular in shape, because it had previously been very slender, and had tended to dip into the water. He also made slight modifications to the position of the undercarriage.
He tested the modified design on the ''Grand Etang'' (Great Pond), a stretch of water in the eastern corner of
Port-Aviation (often called "Juvisy Airfield") at
Viry-Châtillon, where he had first tested the older model. After this test, the wheels were replaced temporarily with water floats.
On 13 April 1912, slightly over a month since the initial test of the first design, Denhaut's craft flew from Port-Aviation and landed on muddy ground close to the
Seine
The Seine ( , ) is a river in northern France. Its drainage basin is in the Paris Basin (a geological relative lowland) covering most of northern France. It rises at Source-Seine, northwest of Dijon in northeastern France in the Langres plat ...
. The aircraft was pushed into the water where it took off and alighted seven or eight times. Denhaut then returned to the bank of the Seine. Denhaut's second model had succeeded in becoming the world's first flying boat. Many later designs for flying boats can be seen to be very clearly based upon Denhaut's design.
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{{DEFAULTSORT:Denhaut, Francois
1877 births
1952 deaths
People from Creuse