The Bartel BM 6 was a Polish biplane trainer

fighter aircraft Fighter aircraft (early on also ''pursuit aircraft'') are military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air supremacy, air superiority of the battlespace. Domina ...

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 prototype ...

stage.

Design and development

The aircraft was designed by Ryszard Bartel 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 Warta, River Warta in west Poland, within the Greater Poland region. The city is an important cultural and business center and one of Poland's most populous regions with many regional customs such as Saint John's ...

, 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 language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...

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 "aeroplane" and "acrobatics". Aerobatics are performed in aeroplanes and gl ...

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

Bucharest Bucharest ( , ; ) is the capital and largest city of Romania. The metropolis stands on the River Dâmbovița (river), Dâmbovița in south-eastern Romania. Its population is officially estimated at 1.76 million residents within a greater Buc ...

in 1930, along with the similar

PZL P.1 The PZL P.1 was a Polish single-seat gull-wing fighter prototype, designed by the engineer Zygmunt Puławski, and manufactured by the Państwowe Zakłady Lotnicze, PZL state aircraft factory. It remained a prototype, but was the first of the Poli ...

. 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 in ...

220 hp

radial engine The radial engine is a reciprocating engine, reciprocating type internal combustion engine, internal combustion engine configuration in which the cylinder (engine), cylinders "radiate" outward from a central crankcase like the spokes of a wheel. ...

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

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, on the front part of an aircraft, spacecraft, or submersible, from which a pilot controls the vehicle. The cockpit of an aircraft contains flight instruments on an instrument panel, and the controls th ...

, 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. Origins The first known V8 was the Antoinette, designed by Léon Levavasseur, a ...

Hispano-Suiza 8 The Hispano-Suiza 8 is a Internal combustion engine cooling, water-cooled V8 engine, V8 SOHC aero engine introduced by Hispano-Suiza in 1914 that went on to become the most commonly used liquid-cooled engine in the aircraft of the Entente Powers ...

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

Radiator A radiator is a heat exchanger 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 taxiing, takeoff or landing. For aircraft, it is generally needed for all three of these. It was also formerly called ''alighting gear'' by some manufacturers, s ...

, with a rear skid. Two-blade wooden

propeller A propeller (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 a working flu ...

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 (, ) 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 province. Grudziądz is one of the oldest citie ...

, then in an aviation training center in

Dęblin Dęblin is a town at the Confluence (geography), 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 together have over 100,000 inhabitan ...

Operators

; *

Polish Air Force The Polish Air Force () is the aerial warfare Military branch, 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 26,000 military personnel an ...

(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