Kraków 2020-02-22
00127a Section 1927-12-20
WWS „Samolot” Bartel BM-4
History
Wielkopolska Aircraft Factory SA „Samolot”.
On 1923-08-11, a joint-stock company under the name Wielkopolska Wytwórnia Planów – "Airplane" was founded, which became the second company, after the E. Plage and T. Laśkiewicz Mechanical Works in Lublin, producing aircraft in Poland. The company was founded on the initiative of the president of the Polish Aviators Union – Czesław Wawrzyniak. On 1924-04-27, a solemn blessing of the factory took place with the participation of the President of the Republic of Poland, Professor Stanisław Wojciechowski.
Initially, the company was not located at Ławica Airport. Her offices and design workshops were located in buildings between the airport and the city center, about 3 km from the airport. It wasn’t until later that the company received the workshop and hangar at Ławica Airport, renting it from the 3rd Air Regiment. Ultimately, WWS Airplane at Ławica Airport had an area of 12.5 ha. Initially, about 100 employees worked in the company. In 1925, as many as 500 people were employed. From 1926, the number of employees decreased.
The managing directors were successively; Piotr Tułacz, Eng. Roman Rosinkiewicz, Kazimierz Nencki. The design office was led by Piotr Tułacz, and from 1926, engineer Ryszard Bartel. It is from his name that some constructions received the name Bartel BM.
One of the reasons for establishing the company was the order for a liner by the Air Navigation Department in 1923. The project was the WZ-VIII-bis aircraft developed by Władysław Zalewski. However, the prototype was not built and production started.
The first aircraft built at the factory was Hanriot-14, which was baptized on 1925-02-22. The act was made by general Włodzimierz Zagórski. This was related to the order received by WWS "Airplane" in 1924 for Hanriot school aircraft. Semi-finished products delivered from France were used for machine construction. In the period 1925-1926, the company built 120 machines, which were initially designated HD-14, and a little later Hanriot H-28. A design office based on Hanriot H-28 has developed a sanitary version for transporting one wounded on a stretcher. The aircraft received the designation H-28s. 80 Hanriot H-19 aircraft were also built. In total, around 200 aircraft from France were built.
Initially, planes were built under a French license. French ways of organizing work were also used. The first own construction of the plant was the SP-1 sport aircraft, whose leading constructor was engineer Piotr Tułacz. The aircraft was built and flown in July 1926.
In December 1926, another sports plane was created, this time under the direction of engineer Ryszard Bartel. The aircraft was designated BM-2. The plane proved to be better than its predecessor. Already in 1927, an improved school aircraft marked BM-4 was created. The plant received an order for its serial production and in 1928, made 22 machines. Bartel BM-4 planes were created in several engine versions. Also in 1928, the BM-5 was created, also intended for training. It was mass-produced in 1929-1930.
Bartel BM-2
The BM-2 made its first flight on 1926-12-07, after half a year of construction. The aircraft proved successful and it was planned to launch its serial production. Ultimately, production was not undertaken.
Bartel BM-4
The construction of the BM-4 prototype began in March 1927. The plane had identical wings as the Bartel BM-2. In addition, the upper and lower wings are interchangeable. Many components and materials have also been unified.
The Bartel BM-4 aircraft made its first flight on 1927-12-20. The pilot was Edmund Hołodyński, who was the factory pilot of WWS "Airplane".
The BM-4 turned out to be better than the BM-2 and much better than the Hanriot H-28, which was produced in WWS "Airplane". The BM-4 was stable, controlled and correct in flight. The plane did not tend to easily get into the corkscrew. In March 1927, the BM-4 aircraft was presented at Mokotów Airport. The aircraft underwent tests conducted by the Department of Aviation Commission and the Institute of Aviation Technical Research. Finally, the BM-4 was approved as an advanced training aircraft in the Polish Army.
The Bartel BM-4 airplane was equipped with a 85 HP "Walter" star engine. Such a plane was donated by the Polish Government, King of Afghanistan – Aman-Ullach, during his visit to Poland in 1928.
Due to the large number of "Le Rhone" rotary engines available, 80hp, the Polish Army ordered 22 Bartel BM-4 planes with these engines. The BM-4a prototype with the "Le Rhone" engine made its first flight on 04-27-1928. The aircraft was accepted into service on 06-20-1928. The planes were directed to military schools and later to Aeroclubs.
Other versions Bartel BM-4
Other versions Bartel BM-4 to:
BM-4c with engine engineer W. Zalewski "Avia WZ-7", 80 HP.
BM-4e also with the Polish engine engineer F. Peter "Peterlot", with 85 hp.
BM-4f also with the Polish engine of Nowkuński engineer "G-594 Czarny Piotruś", with 100 HP. The aircraft was built in 1930 in PZL Warsaw.
BM-4g with Gipsy engine, 105 HP. The aircraft was built in 1931 in the LOT Polish Airlines workshop.
BM-4h with a Walter-Junior engine, 100 HP. The aircraft was built in 1931, and produced serially at the PWS plant in Biała Podlaska.
Bartel BM-5
The Bartel BM-5 aircraft is a modernized Bartel BM-4 aircraft. The BM-5 aircraft was built in versions a / b / c. The BM-4 and BM-5 aircraft delivered to the Army served in schools in Bydgoszcz and Dęblin as well as in the Naval Aviation in Puck.
In March 1930, another aircraft marked BM-6 was created, but its production was no longer started.
About 20 aircraft were built monthly at WWS "Airplane" plant. A maximum of 35 machines could be built in a month. After the WWS factory fire, a dozen or so planes were built outside of Poznań. In total, approximately 75 Bartel BM-4 aircraft of all versions were built.
Written by Karol Placha Hetman
Kraków 2020-02-22
00127a Rozdział 1927-12-20
WWS „Samolot” Bartel BM-4
Construction
Bartel BM-4 is a school and sports plane, two-seater, biplane, wooden structure.
Wings with wooden structure, interchangeable between position at the top or bottom. The upper lobes are extended in relation to the lower ones. Between the wings there are N-shaped posts made of steel pipes that have been profiled. The crucifixion was made with steel wires. The wing fittings are metal. The wings have a Bartel 37 II a profile, with a profile thickness of 15.8%. The wings cover in the front is plywood, the rest is covered with canvas. The shuttlecocks are on all wings.
The BM-4 fuselage has a rectangular cross-section and slightly rounded from above. The front part of the fuselage is of circular cross-section, made of sheets that cover the engine. The engine bed is made of steel pipes and is attached to wooden stringers with the help of fittings. Behind the engine there is a fuel tank with a capacity of 82 liters and an oil tank with a capacity of 7.5 liters. The engine space from the hull is separated by a firewall made of aluminum sheet. Two-seater cabin. The controls are in both cabins. The onboard instruments are only in the first cabin. Some of them are on the pillars to be visible from the other cabin. The seats are adjustable and adapted for sitting and back parachutes.
Classic fitting made of steel pipes connected by welding. The cover was made of canvas.
Classic chassis. Main landing gear wheels 0.70 m in diameter, mounted on a common axle. Shock absorbers made of rubber rings.
Engines on Bartel BM-4 planes.
Version BM-4a – "Le Rhone" rotary motor, 80 HP, 120 revolutions per minute. The engine weight is 115 kg. Fixed propeller, two blades, Szymański HT-2, made of wood, gluing method. The propeller diameter is 2.55 m.
Version BM-4b received a star engine, 7-cylinder, "Walter" with 85 hp.
Version BM-4c with engine engineer W. Zalewski "Avia WZ-7", 80 HP.
Version BM-4e also with the Polish engine of engineer F. Peter "Peterlot", with 85 HP.
Version BM-4f also with the Polish engine of Nowkuński engineer "G-594 Czarny Piotruś", with 100 HP. The aircraft was built in 1930 in PZL Warsaw.
Version BM-4g with Gipsy engine, 105 HP. The aircraft was built in 1931 in the LOT Polish Airlines workshop.
Version BM-4h with Walter-Junior engine, 100 HP. The aircraft was built in 1931, and produced serially at the PWS plant in Biała Podlaska.
Data T-T Bartel BM-4a
Span 10.17 m
Length 7.22 m
Height 2.89 m
Bearing area 25 m2
Curb weight 538 kg
Total weight 791 kg
Fuel weight 65 kg
Maximum ceiling of 3,750 m
Top speed 125 km / h
Landing speed 55 km / h
Climbing time 9 minutes 40 seconds on 1,000 m
Climbing time 23 minutes 20 seconds on 2,000 m
Written by Karol Placha Hetman
Kraków 2020-02-22
00127a Section 1927-12-20
WWS „Samolot” Bartel BM-4
Tally
Bartel BM-4 is a school and sports plane, two-seater, biplane, wooden structure. About 75 aircraft were built.
Written by Karol Placha Hetman