Bartel BM-2

infobox Aircraft
name =Bartel BM-2
type =Primary trainer aircraft
manufacturer = Samolot


caption =
designer =
first flight = 7 December 1926
introduced =
retired =
status = Prototype
primary user =
more users =
produced =
number built =1
unit cost =
variants with their own articles =

The Bartel BM-2 was a Polish biplane primary trainer aircraft prototype of 1926.

Design and development

The aircraft was designed by Ryszard Bartel, a chief designer of Samolot factory in Poznań. It was the first Polish design of a trainer plane. Initially it was known as Bartel M-2, then BM-2 (M was for designer's wife Maryla). The prototype was flown on 7 December 1926 in Poznań. In June 1927 it was shown at the first Aviation Exhibition in Warsaw. It was tested in 1927 and evaluated as quite good, but it was not built in series, because Bartel decided to design an improved aircraft, which resulted in the Bartel BM-4 trainer, which was produced in quantity. After flight testing, the prototype was removed from service.

A distinguishing feature of the BM-2 and all Bartels was an upper wing of a shorter span, because the lower and upper wing halves were interchangeable (i.e. the lower wingspan included the width of the fuselage). Also Bartel put a stress on standardizing the construction materials used: steel pipes, metal sheet etc, in order to make production and repairs easier. A distinguishing feature of the BM-2 was the upper wing directly over the lower wing - unstaggered wings, while in later Bartel designs, the wings incorporate forward stagger - where the upper wing is mounted ahead of the lower wing.

pecifications

Description

Wooden construction biplane, conventional in layout. Fuselage rectangular in cross-section, plywood-covered (engine section - metal covered). Rectangular two-spar wings, plywood- and canvas-covered. Crew of two, sitting in tandem in open cockpits, with individual windshields. Cockpits with twin controls, the instructor seated aft. Fixed landing gear, with a rear skid (main gear with a common axle, sprung with a rubber rope). Radial engine in the fuselage nose, without a cowling. Two-blade wooden propeller 2.24 m diameter. Fuel tanks: 120 l. Cruise fuel consumption: 34 l/h.

aircraft specifications
plane or copter?= plane
jet or prop?= prop

ref=
crew= 2, student and instructor
capacity=
length main= 7.8 m
length alt= 25 ft 7 in
span main= 11.77 m
span alt= 38 ft 7¼ in
height main= 3.08 m
height alt= 10 ft 1¼in
area main= 28.6 m²
area alt=308 ft²
airfoil=
empty weight main= 695 kg
empty weight alt= 1,529 lb
loaded weight main= 970 kg
loaded weight alt= 2,314 lb
useful load main= 275 kg
useful load alt= 605 lb
max takeoff weight main=
max takeoff weight alt=
more general=
engine (prop)=Salmson 9 Ac
type of prop= 9-cylinder air-cooled radial engine
number of props=1
power main= 90 kW
power alt= 120 hp
power original=

max speed main= 128 km/h
max speed alt= 69 knots, 80 mph
cruise speed main= 100 km/h
cruise speed alt= 54 knots, 62 mph
never exceed speed main=
never exceed speed alt=
stall speed main= 65 km/h
stall speed alt= 35 knots, 40 mph
range main= 320 km
range alt= 173 nm, 199 miles
ceiling main= 4,000 m
ceiling alt= 8,800 ft
climb rate main= 2.9 m/s
climb rate alt= 570 ft/min
loading main= 33.8 kg/m²
loading alt= 7.51 lb/ft²
power/mass main= 0.093 kW/kg
power/mass alt= 0.052 hp/lb
more performance=
armament=
avionics=

ee also

aircontent
related=
*Bartel BM-4 - Bartel BM-5
similar aircraft=

lists=
see also=

References

*Andrzej Glass: "Polskie konstrukcje lotnicze 1893-1939" ("Polish aviation constructions 1893-1939"), WKiŁ, Warsaw 1977 (Polish language, no ISBN)

External links

* [http://www.airwar.ru/enc/other1/bm2.html Photo and drawings] at [http://www.airwar.ru Ugolok Neba site] (in Russian)