| M.N.5 | |
|---|---|
 | |
| Role | Civil trainer aircraft |
| National origin | Poland |
| Designer | Józef Medwecki and Zygmund Nowakowski |
| First flight | 21 August 1930 |
| Number built | 1 |
The Medwecki and Nowakowski M.N.5 was an economical Polish trainer aircraft initially aimed at the club market, though there was also some military interest. It performed well but lacked a constructor after Samolot became insolvent in 1930, so only one was completed.
The increasing number of Polish aeroclubs in the early 1930s called for a suitable training aircraft. LOPP, the group that encouraged Polish air-mindedness put out a call for suitable designs, powered by a 60 kW (80 hp) engine, that would be cheap to buy and to run. Three designs received development contracts, the PZL 5, the Sido S.1 and the M.N.5. The latter was designed by Józef Medwecki and Zygmund Nowakowski, both of whom worked for Samolot. With the company's help, two M.N.5 airframes were built, one for static load testing and the other for flight. [1]
The wood-framed M.N.5 was a single bay biplane with stagger and a large interplane gap to ease cockpit access. The equal span upper and lower wings were both in two parts with rectangular plans out to blunted tips. They were built around pairs of spars and largely covered with fabric, together with some plywood. Upper and lower wings were braced together with conventional N-form interplane struts but in addition a long steel tube strut, larger in diameter than the others, ran in the plane of the forward spars from the top of the interplane strut down to the lower spar just outboard of the root. As well as replacing flying wires, this strut supported the leading edge of the lower wing when the wings were disconnected from the root and folded back alongside the fuselage, hinging on the rear spars. The wing root was strengthened by an inverted V-strut from its spars to the upper fuselage longeron. The upper centre section was formed by an aerofoil section fuel tank, held over the upper fuselage by three pairs of struts, the forward-most leaning rearwards to the forward spar and the others, in parallel, outwards to the rear spars. Only the lower wing was mounted with dihedral; it also carried the M.N.5's full span, narrow chord ailerons. With wings folded, the M.N.5 was 3 m (9 ft 10 in) wide. [1]
The M.N.5 was powered by a 60 kW (80 hp) Armstrong Siddeley Genet five-cylinder radial engine enclosed by a Townend ring. The mostly wooden fuselage had four longerons connected by frames, though the forward part was reinforced with steel tubes. Its covering, including rounded decking, was plywood. There were two cockpits in tandem, fitted with dual control. The instructor sat in front under the wing and the student just aft of the trailing edge. Behind the pupil's cockpit there was a third seat under a detachable ply cover. [1]
Its curved and slightly pointed empennage was steel-framed and fabric-covered with a rudder that extended down to the keel. The tailplane's angle of incidence could be adjusted in flight. There were separate elevators, each identical to each other and to the rudder, keeping costs down. [1]
The M.N.5 had a wide track, divided undercarriage with mainwheels on cranked half-axles hinged from the fuselage underside centreline; a Vickers oleo strut from the stub wing and a radius arm formed a V-strut on each side. Its short tailskid had a vertical, rubber cord shock absorber. [1]
It flew for the first time on 21 August 1932 from Poznań-Ławica. Early testing revealed some stability problems which were overcome by moving the engine forward 300 mm (11.8 in) in a longer nose. [1]
The M.N.5 was then flown by both civil and service pilots, who remarked on its good handling and manoeuvrability. The Department of Aeronautics, looking for a replacement for its Hanriots, was enthusiastic and the construction of a second prototype to speed development was proposed. Unfortunately, as Samolot was in the process of liquidation, another builder had to be found. The Ministry proposed PZL who were developing the PZL 5 and showed no interest in helping a competitor, so no more N.M.5s were built. [1]
The lone example was bought by the Vilnius aeroclub in 1931 and, registered as SP-AEH, served them for many years. It took part in many rallies and competed in regional and national championships. [1]
Data from Cynk (1971) [1]
General characteristics
Performance
The PWS-5 or PWS-5t2, was a multi-seated Polish liaison aircraft, developed in 1928 by PWS.
The Meyers Midget was a one-off small, low-powered, sporting single-seat sesquiplane, designed and built in the United States in 1926, incorporating several innovative structural features.
The Hanriot HD.15 was a French two seat fighter aircraft fitted with a supercharger for good high altitude performance, built in the 1920s. Three were ordered by Japan but lost at sea during delivery.
The Hanriot H.26 was a French single seat fighter aircraft prototype completed in 1923. Only one was built.
The Albatros L.71 was a two-seat, single pusher engined biplane built in Germany in the 1920s.
The Villiers IV or Villiers 4 was a French two seat naval floatplane. Two were built, the first with twin floats and the second with one. The first was short-lived but the second set several world and national records; it later became the Villiers XI.
The Heinkel HD 20 was a twin engine, three seat German biplane built in 1926 for civil survey work.
The Skraba S.T.3 was a two-seat Polish biplane built in 1928. It was the first all-metal aircraft designed in Poland; only one was completed.
The Medwecki HL 2 was a Polish two seat lightplane flown in 1927. Handicapped by a low power, unreliable engine, its flying life lasted little more than a month.
The Offierski O.2 was a one-off, two seat, low powered lightplane built in Poland on the late 1920s. It flew in 1928 but an old and unreliable engine prevented its development.
The Medwecki and Nowakowski M.N.3 or just M.N.3 was a low-powered, four seat, Polish aircraft flown in 1928. The sole example was modified into a more powerful two-seater which served aeroclubs until World War II.
The Rogalski and Wigura R.W.1 was designed and built by a pair of students at Warsaw Technical University in 1927. The single example was a two-seat parasol-wing monoplane which entered two national competitions, served the Warsaw Academic Aeroclub and also towed an advertising banner.
The Gabriel P 6 was a Polish training aircraft and the P 7 a tourer. The difference between them was the wing configuration, chosen to optimise their speed range for their role, so the P 6 was a biplane and the P 7 a parasol wing aircraft.
The Silesia S-4 was a Polish, low-power parasol wing aircraft built in 1925. After an engine change and airframe modifications it became one of the Silesian Aeroclubs fleet. It was lost in a take-off accident in 1931 and was the last Silesia aircraft to fly.
The Działowski D.K.D.4 was a Polish, parasol-wing, sports two-seater built in 1928. One won the Second National Lightplane Contest, with another coming fifth.
The Zalewski W.Z.XI Kogutek I was a basic, single seat sport aircraft designed and built in Poland in the 1920s. Its engine was also designed and built by Zalewski, making it the first all-Polish aircraft to fly.
The Kozlowski WK.3 was a one-off Polish biplane trainer. It first flew in 1933 and was later re-engined, serving an aeroclub until the invasion of Poland.
The Sido S.1 was a Polish two seat, parasol wing trainer aircraft, first flown in 1930.
The American Eagle Phaeton was an American three seat, single engine sports biplane produced from 1929 until American Eagle failed financially in 1932. About 34 were built.
The Franklin Sport is a two seat sport and training biplane built in the U.S. in 1930. Several different engines, in the power range 55–90 hp (41–67 kW), were fitted. Two remained airworthy in 2011.