Letov Projects

borovik

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Visual addendum to:Letov Pre-1945 Designations
http://www.secretprojects.co.uk/forum/index.php/topic,5788.0.html
Airliners-
 

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  • Letov S -30.jpg
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  • Letov S-41 (variant).jpg
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  • Letov S-41 twin-fuselage var..jpg
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  • Letov S-50D (transport).jpg
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borovik

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Bombers-
 

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  • S-50 (in Brusel).jpg
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  • Letov S-49.jpg
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  • Letov S-43.jpg
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  • Letov S-29.jpg
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borovik

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Fighters, attack aircraft and others-
source: V. Nemechek "Czechoslovak aircraft 1918-1945" Volume 1.,
 

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  • Letov S-51.jpg
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hesham

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a great stuff,thank you my dear Borovik.
 

Apophenia

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Yes, fabulous stuff Borovik. Many thanks.

I've added some of the details to the Letov designation list. Cheers!
 

Sarastro

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Hi,
Letov Š.49, two-seaster fighter and battle-plane. It did not get beyond the stage of a full-size model, 1936. Walter Sagitta engines, span: 15,8 m, length: 11,5m.
From: Československá letadla vol.1 V.Něměček and my speculative drawing.
Letov Š.49.jpg Letov Š.49_.jpg
 
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Sarastro

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Hi,
in the period from November 1938 to February 1939, chief designer Šmolík and his team worked intensively on the Letov Š.50D type. Compared to the military version, it was to have a completely new, larger fuselage, the wings and tail surfaces, on the contrary, remained identical to the type of Š.50. The model was measured in a wind tunnel, the aircraft was close to building a prototype. Two Avia RK 17 engines, 10 passengers, span 17.3 m, length 13.2 m.
From: Československá letadla vol.1 V.Něměček and my speculative drawing. Letov Š.50D.jpg View attachment Letov Š.50D_.jpg
 
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Sarastro

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Hi,
Letov Š.44B.
1936 was a turning point in the attitude of the MNO (Ministry of National Defense) towards the modernisation of the Air Force. The immediate impetus for activating the Czecoslovak aviation companies was the prototype construction programme, prepared by the Aviation department of the MNO in January 1936 and issued under the filing number 23-308 dův. III/.36. It requested proposals for four categories of aircraft: Type I - single-seat fighter, Type II - two-seat fighter/attack aircraft. Type III - Three-seat day/night observation aircraft and Type IV - multi-place day/night light bomber.
The only type that corresponded to the Type I category and was built in prototypes was the Avia B.35. Other aircraft factories were also preparing their projects. One of them was Letov Š.44B and Aero A-107 (https://www.secretprojects.co.uk/threads/aero-projects.9099/). Letov Š.44B was to have a span of 9.5 and a length of 8.7 m. It was only slightly larger than the A-107 (span 8.4 m, length 7.6 m), so we can assume that with the same type of engine (both aircraft had Walter Sagitta), they would have similar performance. No information has been preserved about the Š.44B Type, so I present the Aero A-107 performance table.

The presumed performance parameters of the Aero A-107.
wingspan 8,4 m
overall length 7,6 m
wing area 11,3 m²
empty weight 941 kg
take off weight 1 434 kg
maximum horizontal airspeed at 3 700 m 490-500 kph
cruising speed at 3 700 m and 70 % power 420-430 kph
time to 4 000 m 4 min 40 s
service ceiling (m) 8 800

From: Československá letadla vol.1 V.Něměček and my speculative drawing. Letov Š.44B_.jpg Letov Š.44B_0.jpg
 
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Sarastro

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Hi,

Letov Š.41c from 1934. The project was developed in several variants, version Š.41 and version Š.41b are mentioned in Bittner's collection, which is located in the National Technical Museum in Prague. Calculated dimensions of the aircraft from the picture. Length 16.1 m, span 23.5 m and fuselage height in the passenger compartment 1.6 m.
I would like to know what led the main designer Šmolík to choose this concept. The thickness of the wing profile is considerable, the fuselage would pass through the wing beams, which would prevent movement (similar to the Boeing 247). And I'm not talking about a retracted chassis wheel, which would also take up a lot of space. It would be a total discomfort for the passengers, but also for the pilot...

From: Československá letadla vol.1 V.Něměček and my speculative drawing.
Letov&Bittner.png Letov Š.41c.jpg Letov Š.41c_.jpg
 
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Sarastro

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Hi,

project of fighter Letov Š.51from 1937. This is one of the two proposed forms of the aircraft, the second is mentioned in Bittner's collection (no further information). Length 10 m and span 11.4 m, Gnome-Rhône 14N engine, two 20 mm cannons. With similar dimensions and with the same engine, the performance would correspond to the Bloch MB.152 aircraft...

From: Československá letadla vol.1 V.Něměček and my speculative drawing. 1.png Letov Š.51.jpg Letov Š.51_.jpg
 
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Sarastro

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Hi,

Letov Š.41a one of the five variants of this aircraft. I have no information about the other three, but Bittner's collection mentions them (see my post above in this thread). Span 22.2 m, length 16.1 m, 12 passengers.

From: Československá letadla vol.1 V.Něměček and my speculative drawing.
Letov Š.41a.jpg Letov Š.41a_.jpg
 
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Sarastro

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Hi,

Some information about Letov's pre-war aircraft. Unrealized studies and types about which there is no information are marked in bold.

Chief designer Alois Šmolík (1893-1952) after the occupation of Czechoslovakia in 1939 was forced by the new German leadership to resign. At the end of November 1943, he left Letov permanently and moved to the small town of Příbram, where he devoted himself fully to the management of his engineering plant and foundry, which he inherited. He never returned to work in the aviation field...

Letov Š.A, Š.1. Prototype and 28 serial aircraft for MNO.

Letov Š.137. A seven-engine transatlantic transport aircraft for 50 passengers. Total engine power 2,400 hp, aircraft weight 22,000 kg, cruising speed 200 km / h, study 1920.

Letov Š.2. Model No. 1 built under license from the company Aero in the number of 40 pieces 1921.

Letov Š-B-1, Š.3. Experimental upper wing. 1 prototype 1921.

Letov Š-HS-1.01, Š.4. Prototype and 20 serial machines 1921.

Letov Š.5. Test reconnaissance aircraft, identical in shape to Š.1. 1st prototype 1923.

Letov Š.6. Bomber. Prototype and aircraft series of 35 aircraft 1923.

Letov Š 7. Experimental fighter aircraft. 1 ptotoyp 1923.

Letov Š.8. Racing topplane. 1 prototype 1923.

Letov Š.9. Three-engine bomber with a tandem landing gear in large gondolas under the wings. One 450 hp engine and two 240 hp engines, 1923 study.

Letov Š.10. School plane built 36 pieces, a copy of the Brandenburg B-1 1923.

Letov Š.11. A twin-engine bomber with two Walter engines of 220 hp, study 1923.

Letov Š.12. Upper plane, whose thick wing of great depth was mounted on the fuselage W.4. 1 prototype 1923.

Letov Š.13. Biplane with a thick profile of new semi-self-supporting wings mounted on the fuselage W.7. 1 prototype 1923.

Letov Š.14. Installation of the Hispano Suiza 8Fb engine by 300 hp into the airframe Š.4.20. 1 prototype 1923.

Letov Š.? 15. Light experimental sports aircraft with a Walter engine with a power of 30k. Mr. Šmolík returned to this project in 1931 with project Š.39, study.

Letov Š.16. Bomber and reconnaissance aircraft with an all-metal skeleton, built 125 pieces in 1925.

Letov Š.116. Bomber and reconnaissance aircraft, built 3 prototypes 1928.

Letov Š.216. Bomber and reconnaissance aircraft, built 1 prototype 1928.

Letov Š.316. Bomber and reconnaissance aircraft, built 3 prototypes 1928.

Letov Š.416. Bomber and reconnaissance aircraft, built 1 prototype 1929.

Letov Š.516. Bomber and reconnaissance aircraft, built 2 prototypes of 1930.

Letov Š.616. Bomber and reconnaissance aircraft, built 12 pieces in 1931.

Letov Š.716. Bomber and reconnaissance aircraft, built 1 prototype 1930.

Letov Š.816. Bomber and reconnaissance aircraft, built 2 prototypes of 1931.

Letov Š.17. Bomber and reconnaissance aircraft, built one prototype, BD-500 engine, based on type Š.16 1928.

Letov Š.18. School plane, made a series of 34 pieces 1924.

Letov Š.118. School plane, made a series of 14 pieces 1925.

Letov Š.218. School plane, built 34 pieces 1928.

Letov Š.19. Transport aircraft, during the construction of the building units of the aircraft Š.6, 7 pieces were assembled for ČSA 1924.

Letov Š.20. Fighter, built a series of 114 pieces in 1924.

Letov Š.21. Training fighter, built 2 prototypes 1925.

Letov Š.22. Fighter high-altitude aircraft, built 1 prototype, Škoda L engine, 450 to 1925.

Letov Š.23. Bittner collection, study.

Letov Š.24. Night bomber modified from Š.16, study 1927.


Letov Š.25. School continuation aircraft, built 3 prototypes 1928.

Letov Š.26. Bittner collection, study.

Letov Š.27. Three-engine airliner, Walter Jupiter engines, 18 passengers, study 1928.


Letov Š.27. School continuation aircraft, construction of 2 pieces canceled in advanced condition, 1931.

Letov Š.28. Observation and light reconnaissance aircraft, built 1 prototype 1928.

Letov Š.128. Observation aircraft, Walter Jupiter engine, built 19 pieces of 1930.

Letov Š.228. Observation aircraft, built 5 pieces, 1931.

Letov Š.328. Observation aircraft, built 412 pieces, 1932.

Letov Š.428. Observation aircraft, built one prototype, 1929.

Letov Š.528. Observation aircraft, built 7 pieces, 1935.

Letov Š.29. Four-engine bomber, study 1929.

Letov Š.30. Transport four-engine aircraft, Walter Jupiter engines, 18 passengers, study 1928.

Letov Š.31. Fighter, made 22 pieces 1929.

Letov Š.131. Fighter, made 2 prototypes, 1929.

Letov Š.231. Fighter, made 24 pieces, 1931.

Letov Š.331. Fighter, built 1 prototype, 1935.

Letov Š.441. Fighter, made 1 prototype, 1936.

Letov Š.32. Transport aircraft, originally single-engine, designed as a three-engine, built 5 pieces in 1929.

Letov Š.33. Single-engine bomber, built 1 prototype 1929.

Letov Š.34a three-engine biplane, bomber, span 32 m, study from the late twenties.

Letov Š.34b, single-engine three-seater bomber, evolution of the type Š.33, study, early 1930s.

Letov Š.35. No information.

Letov Š.36. Project I, II, Bittner collection.

Letov Š.37. No information.

Letov Š.38. No information.


Letov Š.39. Sports high-altitude aircraft, built 21 pieces, 1931.

Letov Š. 139. Sports aircraft, built 5 pieces, 1933.

Letov Š. 239. Sports aircraft, built 16 pieces, 1935.

Letov Š.40, Š.40a, projects I, Š.40, Š.40b projects II. Airliners, Bittner Collection, study 1934.

Letov Š.41 project I, Š.41, Š.41a, Š.41b, Š41c projects II. Airliners, Bittner Collection, study 1934.

Letov Š.42. Twin-engine bomber biplane, derived from the transport Š.40, made a model for tests in the wind tunnel, Bittner collection, study 1935.

Letov Š.43. Twin-engine bomber, competitive design with type Aero A-300 and Avia B-158, expected speed 435km / h, study 1936.

Letov Š.44a, Š.44b. Light fighter, model made for wind tunnel tests, expected speed 518km / h, Bittner collection, study 1936.

Letov Š.45. No information.

Letov Š.46. No information.

Letov Š.47. No information.

Letov Š.48. Twin-engine bomber, Bittner collection, study 1936.

Letov Š.49. Twin - engine heavy fighter and combat aircraft, study, Bittner collection, study 1936.


Letov Š.50. Twin-engine light bomber, completed 1 prototype out of 2 ordered,

Letov Š.50. Bittner Collection, Project I, II, III, 1936.

Letov Š.50D. Transport twin-engine aircraft, derived from Š.50, Bittner collection, study 1938.

Letov Š.51. Fighter, Bittner collection, project I, II, study 1938.

Letov Š.52. Twin-engine training aircraft, designed for training pilots of multi-engine aircraft, derived from Š.50, study 1938.

Letov Š.53. No information.

Letov Š.54. No information.

Letov Š.55. No information.

Letov Š.56. Twin-engine two-seater fighter, shell construction of the wings and fuselage as in Š.50, study 1938.

Letov Š.57. Connecting aircraft, study 1938.
 
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Sarastro

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Hi,

Design of the Letov Š.29 bomber from 1927. On December 30, 1927, Letov sent to the MNO (Ministry of National Defense) the specifications of this aircraft, stating: „Biplane with a five-member crew, 2 pilots, observer, radio operator, shooter. Engines in tandem between the wings symmetrically placed two on each side. Metal propellers, three Lewis machine guns, bomb load capacity 1500 kg, max. Speed 175 km / h."

From this version Š.29 was derived type Š.34 (the first with this designation), a biplane, which was to have three Walter Jupiter engines. Two engines were to be between the wings, the third in the bow of the fuselage. Span 32 m.

In 1929, the chief designer Šmolík decided to thoroughly modernize Š.29 to the form drawn by Mr. Němeček in his book. The span of this version was to be 34 m and the length 18 m.

From: L+K and Československá letadla vol.1 V.Něměček
Letov Š.29 1927.png Letov Š.29a.jpg
 

Sarastro

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Hi,

On March 22, 1930, the MNO (Ministry of National Defense) ordered two pieces of the Š.34 aircraft from the Letov company. It was to be a three-seater single-engine aircraft, with a carrying capacity of 800 kg bombs, speed 200 km / h. The construction was probably never started, because Letov had a lot of problems with the type Š.33, from which the Š.34 was based directly. In these photos, the image of type Š.34 is probably captured.

From: L+K
Letov Š.34.png Letov Š.34_.png
 

Sarastro

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Hi,

The proposed Š.43 bomber was to be i rival for the Aero A-300 type and the Avia B-158b bomber version in the Type IV category (Type IV - multi-place day/night light bomber, one of the four categories of aircraft required by the Czechoslovak Ministry of Defense, 1936).

From: Československá letadla vol.1 V.Něměček and my speculative drawing.
Letov Š.43.jpg Letov Š.43_.jpg
 
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Sarastro

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Hi,

Perhaps as early as Januar 1938, a design for the Letov Š.52 was developed for the training of crews of multi-engine aircraft. Surprisingly, it was of mixed-construction althoung its outline matched roughly the concept on the Š.50 and the power units remained the same Avia Rk-17 engines, evidently with the aim of cost reduction. The fuselage was to be based upon a tubular-steel structure covered by fabric and the wings were to be of wooden structure. Span 18,7 m, length 14 m.

From: Československá letadla vol.1 V.Něměček and my speculative drawing.
Letov Š.52.jpg Letov Š.52_.jpg
 

Sarastro

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Hi,

Project of the Š.57 aircraft from the summer of 1938. Span 10.6 m, length 7.0 m. Walter Major 4 engine with an output of 95 hp. This project concluded the pre-war type series of aircraft of chief designer Šmolík at the company Letov.

From: Československá letadla vol.1 V.Něměček and my speculative drawing. Letov Š.57.jpg Letov Š.57_.jpg
 

hesham

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Hi Sarastro,

I got those Projects from Letectvi magazine of late 1940s,but I can't specify what was the issue ? could
you ? ;

S.9 transport for 30-passenger
S.10 trainer aircraft
S.11 twin-engined commercial monoplane,may be never completed
 

Sarastro

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Hi Sarastro,

I got those Projects from Letectvi magazine of late 1940s,but I can't specify what was the issue ? could
you ? ;

S.9 transport for 30-passenger
S.10 trainer aircraft
S.11 twin-engined commercial monoplane,may be never completed
Hi Hesham,

In the chronology of the designation Letov is given under the number:

Š.9 Three-engine bomber with a tandem landing gear in large gondolas under the wings. One 450 hp engine and two 240 hp engines, 1923 study.
Š.10. School plane built 36 pieces, a copy of the Brandenburg B-1 1923.
Š.11. A twin-engine bomber with two Walter engines of 220 hp, study 1923.

I have no information that there were other aircraft projects under this designation. Bittner's collection mentions that there was also only one type of aircraft under these numbers.

PS: After 1945, the designation of Letov aircraft changed, instead of the letter Š, they are marked L, so I assume that your question concerns pre-war projects.

1.png Letov Š.9.jpg
 

hesham

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Thank you Sarastro,

and I want to know the issue of Letectvi magazine of late 1940s,which mentioned
those Projects ?,if you know.
 

Sarastro

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Thank you Sarastro,

and I want to know the issue of Letectvi magazine of late 1940s,which mentioned
those Projects ?,if you know.
Hi Hesham,

I have had the Letectví magazine in my archive since 1963. The exception is the complete year 1950, but there is nothing about the Letov company in it.
 

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