The Bartel BM 6 was a Polish biplane trainer

fighter aircraft Fighter aircraft are fixed-wing military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air superiority of the battlespace. Domination of the airspace above a battlefield ...

of 1930. It did not advance beyond the

prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototyp ...

stage.

Design and development

The aircraft was designed by

Ryszard Bartel Ryszard Bartel (22 March 1897 – 3 April 1982) was a Polish engineer, aircraft designer and aviator, one of Poland's aviation pioneers. Life and career Bartel was born in Sławniów village near Pilica. He was interested in aviation from h ...

in the

Samolot Samolot (full name: Wielkopolska Wytwórnia Samolotów ''Samolot'' '' S.A.'') was the Polish aerospace manufacturer, located in Poznań and active between 1924 and 1930. It manufactured among others aircraft under the Bartel name. The name ''Samo ...

factory in

Poznań Poznań () is a city on the River Warta in west-central Poland, within the Greater Poland region. The city is an important cultural and business centre, and one of Poland's most populous regions with many regional customs such as Saint John ...

, as a trainer-fighter plane. The BM-6 prototype, designated BM 6a, was flown on 8 April 1930 in Poznań. Its advantage was an easy construction and maintenance, according to Bartel's design philosophy. A distinguishing feature of all Bartels was an upper wing of a shorter span, because lower and upper wing halves were interchangeable (i.e. the lower wingspan included the

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

width). It first introduced a mixed construction to Bartel's designs. After trials, the prototype was modified in July 1930. The prototype was later redesignated BM 6a/II after it was substantially modified. It offered quite good flight characteristics and was capable of

aerobatic Aerobatics is the practice of flying maneuvers involving aircraft attitudes that are not used in conventional passenger-carrying flights. The term is a portmanteau of "aerial" and "acrobatics". Aerobatics are performed in aeroplanes and glid ...

flight. It was demonstrated in a fighter-plane competition in

Bucharest Bucharest ( , ; ro, București ) is the capital and largest city of Romania, as well as its cultural, industrial, and financial centre. It is located in the southeast of the country, on the banks of the Dâmbovița River, less than north of ...

in 1930, along with the similar

PZL P.1 The PZL P.1 was a Polish fighter, designed by the engineer Zygmunt Puławski, manufactured by the PZL state-owned factory. It remained a prototype, but it was the first of the Polish PZL gull wing fighter series, leading to the PZL P.7, PZL P.11 ...

. The second prototype BM 6b, with a

Wright Whirlwind The Wright Whirlwind was a family of air-cooled radial aircraft engines built by Wright Aeronautical (originally an independent company, later a division of Curtiss-Wright). The family began with nine-cylinder engines, and later expanded to incl ...

220 hp

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ca ...

, was ordered, but work upon it ceased with closure of the Samolot factory in mid-1930. The

PWS PWS may refer to: * Pressure wave supercharger, a type of super-charger technology *Performance work statement, term used to summarize the work that needs to be done for a contract * Personal weather station, a weather station owned and operated by ...

works, which inherited many of Samolot's projects, did not continue the project, for it had its own similar design, the

PWS-11 The PWS-11 was a Polish aerobatic and trainer aircraft, developed in 1928-1929 by PWS (''Podlaska Wytwórnia Samolotów'' - Podlasie Aircraft Factory), which remained a prototype. Design and development In parallel with development of a fighter ...

Description

Mixed construction

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

. Steel framed

, rectangular in cross-section, canvas covered (engine and upper sections - aluminum covered). Rectangular two-spar wings with rounded ends, plywood and canvas covered. Upper wing span: 7.36 m, lower wing span: 8.10 m. Lower and upper wing halves were interchangeable. Single pilot, sitting in open

cockpit A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...

, with a windshield. The

V8 engine A V8 engine is an eight-cylinder piston engine in which two banks of four cylinders share a common crankshaft and are arranged in a V configuration. The first V8 engine was produced by the French Antoinette company in 1904, developed and us ...

Hispano-Suiza 8 The Hispano-Suiza 8 was a water-cooled V8 SOHC aero engine introduced by Hispano-Suiza in 1914, and was the most commonly used liquid-cooled engine in the aircraft of the Entente Powers during the First World War. The original Hispano-Suiza ...

Be was modified to lower power output (from 220 hp to 180 hp).

Radiator Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars, buildings, and electronics. A radiator is always a ...

below the fuselage. Fixed

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...

, with a rear skid. Two-blade wooden

propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...

of fixed pitch. Fuel tank in fuselage: 168 L capacity.

Operational history

After state trials in 1931, the prototype was used in an advanced training school in

Grudziądz Grudziądz ( la, Graudentum, Graudentium, german: Graudenz) is a city in northern Poland, with 92,552 inhabitants (2021). Located on the Vistula River, it lies within the Kuyavian-Pomeranian Voivodeship and is the fourth-largest city in its prov ...

, then in an aviation training center in

Dęblin Dęblin is a town at the confluence of Vistula and Wieprz rivers, in Lublin Voivodeship, Poland. Dęblin is the part of the agglomeration with adjacent towns of Ryki and Puławy, which altogether has over 100 000 inhabitants. The population of ...

Operators

; *

Polish Air Force The Polish Air Force ( pl, Siły Powietrzne, , Air Forces) is the aerial warfare branch of the Polish Armed Forces. Until July 2004 it was officially known as ''Wojska Lotnicze i Obrony Powietrznej'' (). In 2014 it consisted of roughly 16,425 mil ...

(single prototype)

Specifications (BM 6a)

References

External links

Photos and drawingsUgolok Neba site
(in Russian) {{Bartel aircraft BM 6 Single-engined tractor aircraft Biplanes 1930s Polish military trainer aircraft Aircraft first flown in 1930