In 1934, the Ministry of
Air issues a specification for the realization of a plane capable
of flying over the South Atlantic, connecting Dakar to Natal in
Brazil. The demand was a cruising speed of 250 km / h at 2/3 of
the engine power and the aircraft had to be able to carry 1000 kg
of load with a range of 3000 kms.
Many manufacturers are responding
to the program, and the Lioré & Olivier Company receives,
on October 10, 1935, an order for the supply of a prototype: the
LéO H47.
The design of the aircraft
is led by Mrs Mercier and Benz who were responsible for the wings
and the fuselage respectively. The company Lioré & Olivier
has a wind tunnel, which explains the very elegant and successful
design of the prototype. This one, manufactured in the Argenteuil
plant, is delivered in two parts to Antibes where the final assembly
is made. The aircraft made its first flight on July 25, 1936.
The Leo H.47 is of all-metal
construction. It is powered by four Hispano-Suiza 12Ydrsl / Yfrsl
grouped in pairs. The different tests are going well. The aircraft
greatly exceeds the technical requirements of the program. It flies
at 300 km / h at 3/4 of power, and at 361 km / h at maximum power.
It has an autonomy of 4000 kms. Air France ordered, in March 1938,
five standard aircraft, under the designation of Leo H470. The Navy
is also interested in the aircraft, which could become an excellent
Naval reconnaissance aircraft.
But, on May 19, 1937, when
the Leo H47 was soon to be delivered to Air France, the ptrototype
suffered a serious accident. Following a structural weakness, the
plane sinks to the landing causing the 5 crewmen: there will be
no survivors.
This accident does not question
the order of Air France for 5 aircrafts. The company Lioré
& Olivier, integrated into the SNCASE since the nationalizations,
thus began the manufacture of the aircrafts in his factory of Vitrol.
The serial version differ slightly from the prototype. Following
the accident of the latter, the fuselage is reinforced, and the
design of the mats connecting the wing to the fuselage is modified.
The design of the drift is changed and the fuel capacity is increased.
Under the engine nacelles, we see a device to increase the engine
thrust (see photo below)
The first flight of the series
aircraft took place July 23, 1937 in Vitrol, and after some internal
tests, it is sent to Saint-Raphael for official tests. Air France
crews have had time to fly a bit with the LéO H470, but none
of the 5 LeO H470s will be delivered to Air France ... At the outbreak
of hostilities, the Navy commandeers the 5 machines that are modified
in Saint-Raphael for their new mission of distant reconnaissance.
The fuselage is extended in its front part to receive the glazed
position of the observer / navigator. It receives a defensive armament:
4 machine guns of 7.5mm and offensive with 4 lances bombs for a
maximum of 600kgs of bombs.
The E11 Squadron, based on
the Berre pond, received two aircrafts on December 4, 1939, followed
four days later by a new H470. But this one will be quickly destroyed,
when, on December 10, his pilot puts it by mistake on Lake Urbino
(Corsica), not deep enough ... The last two LéO H470, will
be taken care of on February 15, 1940. before that the Squadron
E11 leaves the pond of Berre for the Lake of Biscarosse. Back on
the pond of Berre from 24 April 1940, the squadron E11 will participate
until the Armistice, with patrols in Mediterranean sea.
After the Armistice, the
LéO H470s are used as transport planes, freight and passengers,
on links between the metropolis and Tunisia. On August 10, one of
the H470s will be shot down by the Italians near Sardinia. On August
1, 1944, Squadron E11 is renamed 11E, but the unit is disbanded
as of August 15. The three surviving H.470s are transferred to the
E9 Squadron based on the Berre Pond. In June 1941, they joined Dakar,
to participate, as aircraft "petroleum", with tests of
refueling at sea, seaplanes torpedo-boats Laté 298 of Escadrille
6T.
After the Allies landed in
North Africa in November 1942, under the colors of Free France,
the LéO H470s will be used to cover allied convoys leaving
Dakar. But the invasion of the free zone by the Germans will ban
the delivery of spare parts, and the Leo H470 are quickly put out
of service. The last Leo H470 will be reformed in August 1943.