Lioré et Olivier LeO 45

https://en.wikipedia.org/wiki/Lior%C...Olivier_LeO_45

Lioré-et-Olivier LeO 45 was a French medium bomber that was used during and
after the Second World War. It had been originally designed and developed for
the newly formed Armée de l'air as a modern medium bomber capable of performing
independent strategic operations, unlike the majority of previous French
bombers.

The LeO 45 was a low-wing monoplane, all-metal in construction, equipped with a
retractable undercarriage and powered by two 1,060 hp Gnome-Rhône 14N engines.
The prototype, which made its maiden flight on 15 January 1937, had been
outfitted two 1,100 hp Hispano-Suiza engines. The LeO 45 had been developed with
the aim of providing a modern and advanced bomber for the new Armée de l'air,
which had gained its independence on 1 April 1933. Introduced to operational
service in 1938, it was a very effective and capable bomber.

As only a handful of aircraft had been introduced into the French Air Force by
the outbreak of the Second World War, the LeO 45 had effectively appeared too
late in order for the type to provide any substantial contribution during the
Battle of France in the face of an invasion by Nazi Germany. As a result of the
Armistice of 22 June 1940, the LeO 45 was being operated in quantity by both
sides of the conflict; while the type continued to be manufactured and operated
by occupied Vichy France, the Free France forces also operated the aircraft. The
LeO 45 participated in combat missions throughout the remainder of the war, and
continued to be used for some time after its end by the post-war French Air
Force. The last examples in active service were finally retired in September
1957.

The Lioré et Olivier LeO 45 was a twin-engined medium bomber, which had been
conceived with the aim of producing a suitably advanced bomber to equip the
French Air Force. In contrast to its predecessors, which had relied on machine
guns for self-protection, the emphasis was placed on high-speed high-altitude
cruise. The expectation was that high speed would force enemy fighters into
tail-chase attacks and to that effect the aircraft was designed with a
rear-firing cannon which possessed an unobstructed rear arc of fire thanks to
the design of the twin tailfins.

The LeO 45 featured an all-metal construction and a monocoque fuselage; the
structure included 60 individual fixed frames attached to longitudinal stringers
and was covered by flush-rivetted light alloy panels. As a consequence of the
specified speed requirements of the programme, a lot of effort was spent in
reducing parasitic drag. The fuselage cross-section was reduced via the adoption
of not a main fuselage bomb bay paired to smaller bomb bays that were located
within the wing roots. The low cantilever wing, which employed a structure
designed and patented by Mercier, was constructed in four separate sections.
Specifically, the inner section was built around two spars equipped with steel
booms which had enough room between them to accommodate a 200 kg-class bomb and
large self-sealing fuel tanks; the spars did not continue to the wing-tip but
made way for a box-type structure. The wings were furnished with large
split-type slotted flaps, which were electronically controlled and high
aspect-ratio slotted ailerons, the latter of which being depressed during
takeoff.

Role
Medium bomber

Manufacturer
SNCASE, SNCAO

First flight
15 January 1937

Introduction
1938

Retired
1957

Status
Retired

Primary user
French Air Force

Produced
1938–1942

Number built
561

At the outbreak of World War II, only ten LeO 45s had been formally accepted by
the French Air Force. These aircraft were issued to a front line unit to
experiment with the new type in the field and flew a few reconnaissance flights
over Germany, which resulted in the type's first combat loss.

At the start of the Battle of France on 10 May 1940, only 54 of the 222 LeO 451s
that had been delivered were considered ready for combat, the remainder being
used for training, spares, undergoing modifications and repairs or having been
lost. The first combat sortie of the campaign was flown by ten aircraft from
Groupes de bombardement (bomber squadrons, abbreviated GB) I/12 and II/12 on 11
May. Flying at low altitude, the bombers suffered from heavy ground fire with
one aircraft shot down and eight heavily damaged. Within the next eight days
many of them were shot down, such as the one piloted by sergent-chef Hervé
Bougault near Floyon, during a bombing mission over German troops. By the
Armistice of 25 June 1940, LeO 451 of the Groupement de bombardement 6 (bomber
wing) had flown approximately 400 combat missions, dropping 320 tons of bombs at
the expense of 31 aircraft shot down by enemy fire, 40 written off due to damage
and five lost in accidents. Other statistics state that about 47 bombers were
lost: 26 to fighters, 21 to anti-aircraft fire.

Although the LeOs were typically faster than many fighters and also faster than
almost all other types of bomber, the Luftwaffe was equipped with fighters that
were even faster (such as the Bf-109 and Bf-110). The cruise speed, up to 420
km/h (7 km/min), was one of the strengths of the LeOs performance and made them
difficult to intercept. The diving and climbing speeds were very good as well
(the Italian SM.79 took 17 minutes to reach 5,000 m, compared to 14 for the
LeO), even if not that useful for a bomber. LeOs were optimized for
medium-altitude operations (5,000 m) but were forced to go far lower to search
for and destroy tactical targets, rarely with even a basic fighter escort (P-75,
D.520). LeOs were not unarmed and German fighters had to keep a look out for
their dorsal turret: on 6 June 1940, gunner sergeant Grandchamp, GB II/11 shot
down two Bf 110Cs with the Hispano cannon. German fighters came to avoid this
danger by attacking from below, forcing the LeOs to deploy their retractable
turret, which slowed them.

Another problem had been caused by the Germans' initial strike. Groupement 6 had
50 LeOs but these aircraft had not been dispersed and even lacked capable AA
defence on their airfields. When the Luftwaffe attacked, a total of 40 bombers
were lost. In spite of this, Groupement 6 continued the fight, since the LeOs
were produced at a fast pace (around 4–5/day, over 200 built within 45 days)
allowing them to re-equip. Losses remained high and, on missions, 13 LeOs were
intercepted and four shot down by Luftwaffe fighters. Groupement 6 totalled
around 70 losses both in air and ground but still continued to fight until the
end.

The Germans were not especially interested in the type but on 21 May 1943, the
Luftwaffe requested the Regia Aeronautica to hand over 39 LeO 451s captured by
Italians troops in the SNCASE factory in Ambérieu-en-Bugey (Lyon). The
Luftwaffe, claiming to have previously bought the LeOs, gave in exchange a stock
of 30 Dewoitine D.520s. The 451s were converted into transport aircraft for fuel
and troops. Other LeOs were delivered to the Regia Aeronautica and 12 were put
in service with a ground attack unit, although they saw almost no active
service.

Following the war, the 67 surviving aircraft were mostly used as trainers and
transports. The LeO 451 was retired in September 1957, making it the last
pre-war French design to leave active duty.

Specifications (LeO 451)

General characteristics
Crew: 4
Length: 17.17 m (56 ft 4 in)
Wingspan: 22.52 m (73 ft 11 in)
Height: 5.24 m (17 ft 2 in)
Wing area: 66 m² (710 ft²)
Empty weight: 7,530 kg (16,600 lb)
Max. takeoff weight: 11,398 kg (25,130 lb)
Fuel capacity: 3,235 l (855 US gal)
Powerplant: 2 × Gnome-Rhône 14N -48/49 (or -38/39 or -46/47) 14-cylinder
air-cooled radial engine, 790 kW (1,060 hp) each

Performance
Maximum speed: 495 km/h (260 knots, 300 mph) at 4,000 m (13,125 ft)
Cruise speed: 420 km/h (225 knots, 260 mph)
Range: 2900 km (1,565 nm, 1,800 mi)
Service ceiling: 9,000 m (29,530 ft)

Armament

Guns: 1 × 20 mm Hispano-Suiza HS.404 cannon in dorsal turret, 120 rounds
1 × 7.5 mm (0.295 in) MAC 1934 fixed forward-firing machine gun, 300 rounds
1 × 7.5 mm MAC 1934 in "dustbin" retractable ventral turret, 500 rounds

Bombs: Up to 1568 kg (3,457 lb) of bombs in fuselage and wing root bomb bays 7 ×
200 kg bombs (actual bomb weight: 224 kg or 494 lb)




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