The Š 7 was designed by Alois Smolik and built in 1923 to participate in an official competition for single-seat fighters powered by the 300 hp Skoda-manufactured Hispano-Suiza 8Fb engine. Of similar mixed construction to preceding Smolik¬ designed fighters, the Š 7 was an equi-span single-bay staggered biplane with twin 7,7-mm gun armament. The Š 7 was initially flown with a ring-type frontal radiator, but cooling problems dictated redesign of the radiator system and the prototype was fitted with a redesigned engine cowling and a ventral radiator as the Š 7a. This type failed to attract a production order and further development was discontinued.
Engine: 220 hp V-8 Skoda HS 8Fb Span, 30 ft 6 ½ in (9,30 m) Length, 22 ft 10 3/8 in (6,97 m) Height, 8 ft 8 1/3 in (2,65 m) Wing area, 238.43 sq ft (22,15 sq.m) Max speed, 158mph (255 km/h) Time to 3,280 ft (1 000 m): 15 min Empty weight, 1,682 lb (763 kg) Loaded weight, 2,315 lb (1 050 kg)
Intended as a successor to the Spad 7 and 13 in service with the newly-created Czechoslovak Air Force, and selected in preference to the Š 3 parasol monoplane, the Š 4, initially designated S HS. 1, was a single-bay unstaggered biplane of mixed construction with fabric-covered wooden wings and metal fuselage and tail.
Flown in 1922, the Š 4 was powered by a 220 hp Hispano-Suiza 8Ba engine and carried an armament of two synchronised 7,7-mm Vickers machine guns.
A series of S-4 fighters was ordered, but 20 of these were completed with the 180 hp HS 8Aa engine as Š 4a aerobatic trainers. As a result of low manufacturing standards a number of difficulties were experienced with the S4 which was grounded in 1927, the surviving aircraft being rebuilt in 1928 to Š 4a trainer standard.
Letov Š -4 / SHS-4 Engine: 1 x 220hp Hispano-Suiza 8Ba Max take-off weight: 980 kg / 2161 lb Empty weight: 673 kg / 1484 lb Wingspan: 8.00 m / 26 ft 3 in Length: 6.58 m / 21 ft 7 in Height: 2.62 m / 8 ft 7 1/8 in Wing area: 16.43 sq.m / 176.85 sq ft Max. speed: 232 km/h / 144 mph Cruise speed: 200 km/h / 124 mph Rate of climb: 323 m/min / 1050 ft/min Climb to 5000m: 21 min 50 sec Service ceiling: 5500 m Range: 500 km / 311 miles Armament: 2 x 7.7mm Crew: 1
The first original fighter design to be produced by the Vojenská továrna na letadla (State Aircraft Works) “Letov”. The Š 3 was created by Ing Alois Smolik who had formerly worked for the Austro-Hungarian government Initially designated as S B.1, the original prototype was destroyed in a fire at the Prague-Letnany factory on 5 November 1921, but a second prototype entered flight test early in 1922.
A single-seat parasol monoplane powered by a 185 hp BMW l1la six-cylinder in-line engine and carrying an armament of two 7,7-mm Vickers machine guns, the Š 3 was of mixed construction with a wooden wing and metal fuselage and tail. The Š 3 participated in the International Meeting in Zurich in 1922, taking third place in the precision take-off and landing contest and seventh place in the aerobatic contest. Further development was discontinued in favour of the S 4.
Š.3 Crew: 1 Engine: 1 x 185hp BMW IIIa Max take-off weight: 928 kg / 2046 lb Empty weight: 662 kg / 1459 lb Wingspan: 10.13 m / 33 ft 3 in Length: 7.08 m / 23 ft 3 in Height: 3.04 m / 10 ft 12 in Wing area: 17.60 sq.m / 189.44 sq ft Max. speed: 225 km/h / 140 mph Cruise speed: 195 km/h / 121 mph Rate of climb: 508 m/min / 1650 ft/min Time to 9,840 ft (3000 m): 5.9 min Range: 472 km / 293 miles Armament: 2 x 7.7mm
Since the first controllable heavier-than-air flights had been made, the Austria-Hungarian administration did not intend to establish aeroplane manufacturing in Bohemian or Moravian Lands. An Aeroplane Repairs Works “Al-Ma” was set up by Dr. Martius, being of German origin, in the Prague district of Holešovice in 1916. Several days after the independent state of Czechoslovakia had come into existence on October 28, 1918 the Air Force Corps was founded and an order to move all the aeroplanes and air material to Prague was issued. On November 18, 1918 nine planes were seized by the Czechs and eight of them ferried from the town of Cheb to Prague situated near border on Germany so that the Germans were prevented from flying them into Germany. This unexpected raid was commanded by Cpt. Adamec [Addammaets] who was later appointed the Aeroplane Arsenal`s CO. The ninth Czech pilot had to land in Germany and his aircraft was confiscated.
Every plane was concentrated at the Prague Fair Facility until February 1919. A young P/O Alois Smolik was in charge of repairs. He used to be as an asistant to the Air Expert and Scholar Profesor Miess. The Sm-1 biplane designed by Alois Smolik and flight-tested in Apríl 1919 persuaded the Czechoslovak government to prefer the home-production aircraft to ones imported from France, though 115 French planes were presented them.
Originally built in 1910 as the SH-1 with 127 kW (230 hp) Hiero L engines, the SH-1 was later redesignated Š-1. 28 were built.
The Letov Š-1 was a single-engined, two-seat biplane surveillance aircraft. Designed by Alois Šmolík at Letov Kbely, it was first military aircraft built in Czechoslovakia.
The Š-1 first flew in 1920.
The SM-1 variant was powered by 194 kW (260 hp) Maybach Mb.IVa engines and later redesignated Š-2. 64 were built. This 2 seater was armed with one forward firing machine gun and had a twin movable machine gun in the rear. 28 were built.
Letov Š-2 (re-engined Š-1) at the Kbely museum
The Sm A 1 was a commercial variant with a canopy over the rear cockpit for 2 passengers.
The Letov Š-10 of 1921 was an Š-1 trainer variant with a 100 hp 6-cyl Breitfeld & Danek Blesk (Czech Mercedes DI) engine.
The Letov Š-5 was an Š-1 modified for evaporate cooling trials.
The primary user was the Czechoslovakian Air Force.
S-1
SH-1 / Š.1 Engine: 1 × Hiero 6L inline engine, 169 kW (230 hp) Wingspan: 13.23 m (43 ft 4.75 in) Length: 8.31 m / 27 ft 3 in Height: 3.10m / 10 ft 2 in Empty weight: 861 kg Max takeoff weight: 1,375 kg (3,031 lb) Maximum speed: 194 km/h (120 mph) Range: 715 km / 445 miles Climb to 5000 m: 52 min Service ceiling: 6,000 m / 19,685 ft Crew: 2 Armament: 1x fixed machine gun, 1x twin machine gun on swivel mount
SM-1 / Š.2 Engine: 1 x 260hp Maybach Mb.IVa Max take-off weight: 1492 kg / 3289 lb Empty weight: 970 kg / 2138 lb Wingspan: 13.02 m / 43 ft 9 in Length: 8.52 m / 28 ft 11 in Height: 3.31 m / 11 ft 10 in Wing area: 36.17 sq.m / 389.33 sq ft Max. speed: 198 km/h / 123 mph Cruise speed: 167 km/h / 104 mph Ceiling: 6500 m / 21350 ft Range: 667 km / 414 miles Armament: 3 x 7.7mm, 120kg of bombs Crew: 2
In early 1916 the contemporary reconnaissance aircraft of the Aéronautique Militaire, such as the Caudron G.6, Morane-Saulnier T and Salmson-Moineau SM.1 were proving to be less than sparkling in operations and testing. To provide a suitable replacement The STAé, its Director Colonel Dorand and Établissements Letord, formulated the A3 specification and co-operated in the design of the only respondent, the Letord Let.1.
In 1916, the Letord “Let”, in prototype form, recorded its first flight and this three-man, twin-engined platform was developed along the lines extended-range reconnaissance. To cover the distances required of the type, a multi-engine arrangement was used and this fitted to a relatively large airframe.
The aircraft relied on a traditional biplane wing arrangement for lift and control and the crew required to man its various systems numbered three. “Negative wing stagger” was present in the over-under wing arrangement where the lower planes were set well-forward of the upper sections, making the parallel struts angle rearwards.
Power was from 2 x engines of various makes and models throughout the service life of the aircraft and each was charged with driving two-bladed propellers. The engines were held outboard of the fuselage and atop the lower wing assembly. Each of the three crewmen sat in separate open-air cockpits so communication between them was limited. The undercarriage showcased double-wheeled main legs and a tail skid though a nose leg was usually added to prevent “nose-over” accidents when ground-running (common to larger aircraft of the war). The tail unit was marked by a single vertical fin and low-mounted horizontal planes.
Design of this aircraft was attributed to Emile Dorand.
The Letord A3 reconnaissance bomber family, the Let.1 to Let.7, were essentially similar biplanes with, variously unequal span or equal span wings, with prominent and characteristic negative stagger on their wings, powered by two tractor engines in nacelles mounted short struts or directly on the lower wings and had a fixed tailskid undercarriage. Some aircraft were equipped with a strut-mounted nosewheel to protect the aircraft and its crew from “nosing-over” accidents while landing. The pilot sat in an open cockpit under the upper wing trailing edge, with a gunner in an open position immediately aft, and a third crew-member in an open position in the nose where he could act as gunner, observer, and bomb-aimer.
Let.4
Aircraft were completed, variously, with equal span 4-bay wings or unequal span 3-bay wings with longer span upper wings braced by an A-frame king-post and wires. All the Letord reconnaissance bombers shared similar plywood covered wooden structure fuselages and wooden structure wings and conventional tail-unit.
Of the 250-300 built, the Letord Let.5 was probably the most numerous of a family of 3-seat reconnaissance bombers, designed and built in France from 1916, originally to an A3 (reconnaissance aircraft 3-seat) specification from the STAé (Service Technique d’Aéronautique).
Let.7
The Letord reconnaissance bombers saw widespread service throughout the Aéronautique Militaire, from mid-1917, with 121 operational on the Western Front by November 1917. Most were no longer in front-line use by the Armistice in November 1918.
Variants:
A Letord Let.1
Let.1 A.3 initial reconnaissance version three bay wing. Engines: two 150 hp (110 kW) Hispano-Suiza 8A
Let.2 A.3 reconnaissance aircraft similar to Let.1 three bay wing. Engines: two 200 hp (150 kW) Hispano-Suiza 8Ba
Let.3 Bn.3 night bomber four bay wing. Engines: two 200 hp (150 kW) Hispano-Suiza 8Ba
Let.4 A.3 reconnaissance aircraft also used as a bomber three bay wing. Engines: two 160 hp (120 kW) Lorraine-Dietrich 8A
Let.5 A.3 reconnaissance aircraft three bay wing and missing the nosewheel. Engines: two 240 hp (180 kW) Lorraine-Dietrich 8B Propeller: 2-bladed wooden fixed-pitch Wingspan: 18.06 m (59 ft 3 in) Wing area: 62.3 sq.m (671 sq ft) Length: 11.17 m (36 ft 8 in) Height: 3.66 m (12 ft 0 in) Empty weight: 1,660 kg (3,660 lb) Gross weight: 2,445 kg (5,390 lb) Maximum speed: 170 km/h (110 mph, 92 kn) at 2,000 m (6,600 ft) Maximum speed: 152 km/h (94 mph; 82 kn) at 3,000 m (9,800 ft) Range: 455 km (283 mi, 246 nmi) Endurance: 3 hours Service ceiling: 4,900 m (16,100 ft) Time to altitude: 2,000 m (6,600 ft) in 10 minutes Time to altitude: 4,000 m (13,000 ft) in 20 minutes Armament: Up to 4 7.70 mm (0.303 in) Lewis machine-guns on single or double T.O.3 flexible mounts. Bombload: 130–150 kg (290–330 lb) Crew: 3
Let.6 Ca.3 fighter based on the Let.3 four bay wing. Engines: two 220 hp (160 kW) Hispano-Suiza 8Be Armament: 37 mm (1.5 in) cannon
Let.7 Bn.3 night bomber four bay wing of increased span. Engines: two 275 hp (205 kW) Lorraine-Dietrich 8B engines
In April 1912 Fernand Lescarts, with the financial help of King Albert, travelled from Belgium to the Congo bringing with him a Farman biplane. The Farman was destroyed during the journey whereupon Lescarts designed and built a new biplane, and named it N’Deke Mwaope (White Bird), which flew pretty well until a violent windstorm wrote an end to the story.
An earlier glider had been designed by Le Prieur based on a drawing from a French pamphlet. But when a test flight failed, Le Prieur turned to his friend Aibara for assistance, and Aibara brought in Tanakadate, an aviation pioneer in his own right, to help with the design.
The glider was developed by Yves Le Prieur, a military attache at the French Embassy in Tokyo, Lieutenant Shiro Aibara of the Japanese Navy, and Professor Aikitsu Tanakadate of Tokyo Imperial University’s School of Science, now the University’s Faculty of Science (at the time the University of Tokyo was named Tokyo Imperial University). Also known as the Aihara-Le Prieur, built by Japanese Lieutenant Shiro Aihara and French 2nd Lieutenant Le Prieur using bamboo for the structure.
The team first planned to use an automobile to pull the glider, but on the day of the trial the car broke down and didn’t make it to the test site. Instead they put a small boy aboard and a group of students pulled on the cable attached to the craft.
On the morning of December 5, 1909, a bamboo-framed and white cloth-covered glider was hauled onto the Daiichi Senior High School’s athletic field, Ueno Park, Toyko, today a part of the University of Tokyo’s Faculty of Agriculture on the Yayoi campus. A large number of students took hold of a rope attached to the glider, and then ran as fast as they could, pulling the glider behind them. Soon, spectators witnessed the craft, with a boy aboard, ascend slowly and fly at a height of 3.6 meters for a distance of some 15 meters before drifting down to a smooth landing. “
This was apparently the first, though unofficial, glider flight in Japan, and it represents the very beginning of airplane research.
In the subsequent December 9 test flight, piloted by Le Prieur himself, a car was used, which drove along a street near Shinobazu Pond, Tokyo, towing the glider. This was the first certified fixed-wing aircraft flight in Japan.
In 1911 a biplane with an 18-foot wingspan was designed and built by Lennert in the USA.
Willie Lennert flew in his 18 ft. wing span Lennert Biplane (similar to a Demoiselle-type monoplane but with a second wing added below) powered by a Lennert 20 h.p. engine.
The first non-fatal accident at Cicero occurred in June 1911, to Willie Lennert while he was attempting to fly his small self-built Lennert Biplane.
The Karl Lemberger designed Lemberger LD20b cantilever biplane was one of this kind, designed with readily detachable wings and tailplane so that it could be towed by a car. Whilst towing, the wings were stowed alongside the fuselage. The tailskid was linked to the car via a luggage rack-like frame.
The upper and lower wings of the LD20b were very similar, with the same span, area and straight, near-constant chord, plan. The lower wings were attached to the lower fuselage longerons and the upper ones to cabane struts above the front of the cabin. They were arranged with considerable stagger. The wings were built around two closely spaced spars, with plywood skin from the rear spar forward forming a torsion box and fabric covering behind. Differential ailerons were mounted only on the lower wings.
The wooden, rectangular fuselage was plywood-covered to just behind the pilot’s seat and fabric-covered further aft apart from a curved plywood decking behind the cabin. The fin was integral with the fuselage and unusually shallow with the variable incidence tailplane mounted on top of it, a little above the fuselage and bearing damped elevators. The balanced rudder was much taller than the fin. The enclosed cabin seated two in tandem with the front seat under the upper wing and over the centre of gravity. Dual control was fitted. In front, a Walter Mikron inverted 4-cylinder engine drove a two-bladed propeller.
The LD20b was completed in 1971. Its first flights were made from EDSZ Rottweil-Zepfenhahn,(Germany), piloted by a Me 109 pilot. The next flight from Friedrichshafen, Germany, piloted by Arnold Wagner, an airline pilot, the Swiss aerobatic champion and designer of the Hirth Acrostar.
After its presentation at Friedrichshafen, Leonhard Kurt Kienlein took over ownership and the task of making the structural changes in order to make sure the plane did reach stable flight characteristics. He also maintained the aircraft. An enclosed, all-weather trailer was built to house the LD20. The last flight after a total of 368 hours was in 1998.
Engine: 1 × Walter Mikron 4-cylinder inverted air cooled, 46 kW (62 hp) Propeller: 2-bladed Length: 6.67 m (21 ft 11 in) Wingspan: 7.28 m (23 ft 11 in) Height: 2.20 m (7 ft 3 in) Wing area: 14.00 m2 (150.7 sq ft) gross Empty weight: 300 kg (661 lb) Max takeoff weight: 538 kg (1,186 lb) Maximum speed Est: 178 km/h (111 mph; 96 kn) at maximum take-off weight. Cruising speed: 160 km/h (99 mph; 86 kn) Time to altitude: 1,000 m (3275 ft) in 7 mins Capacity: 2
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