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Zbieranski and Cywinski biplane

Страна: Польша

Год: 1911

Zalewski - W.Z.I - 1913 - Польша<– –>АИС - Аист - 1917 - Россия


C.Jerzy Polish Aircraft 1893-1939 (Putnam)


Zbieranski and Cywinski Biplane

  Zbieranski's book O narodzinach lotnictwa polskiego (About the Birth of Polish Aviation), already referred to at some length under the 'Czeslaw Tanski' heading, was devoted mainly to the development and description of the Zbieranski and Cywinski biplane, which was built in 1910-11 in Warsaw. Unfortunately the history of this interesting project, as told by Zbieranski, having his memory as the only source of reference, is at variance with the known facts. The book established one valid point, however: namely that Tanski was in no way connected with the development of the Zbieranski and Cywinski biplane, as erroneously suggested in interwar publications and repeated by several writers, including the author of this work in some of his early articles, after the war.
  According to Zbieranski's own account, at one of the meetings of the Aviators' Circle in Warsaw, held after the 'first demonstration in Poland of a heavier-than-air machine and its attempts at flight, which took place in the summer of 1909' and was undertaken 'by the French pilot Guyot on the Bleriot Cross-Channel Type' (p. 8 of Zbieranski's book), someone suggested that one of the Circle's members should build an indigenous Polish aeroplane. Zbieranski took up the challenge and went abroad to get acquainted with current design trends. Upon his return, he outlined to the Circle a proposal for a tractor biplane constructed of ash and based upon the 40 hp E.N.V. eight-cylinder vee engine driving a Chauviere airscrew. One of the members, Edward Krzeminski, the owner of a lamp factory, offered to buy the engine, and Zbieranski, having this most expensive item assured, decided to construct the aircraft and went abroad again to purchase the necessary materials.
  Zbieranski went first to Paris, where he saw a Voisin biplane built from steel tubes. The simplicity of this solution appealed to him greatly and induced him to change his design from wood to steel tubing. He travelled to Germany and purchased from Deutz a selection of cold-drawn steel tubes, which were not yet on the market. When Zbieranski returned to Warsaw, Krzeminski backed out of his promise to supply the engine, only helping him to hire a shed next to his factory in Solec Street and letting him use his workshop machinery after working hours. Lacking funds for the engine, Zbieranski took a partner with capital, Stanislaw Cywinski, whom he 'immediately despatched to Paris' to purchase the selected French-built E.N.V. engine (p. 12). 'After a few months of disagreeable work in the shed at 103 Solec Street, where rain water poured down on [my] head', he moved the fuselage framework to Hangar No. 1 of the Aviata factory.
  Writing on p. 13 about another candidate for the partnership, Mieczyslaw Glowacki, who shortly left the enterprise, Zbieranski stated that in the spring of 1910 the work on the aeroplane was already being done in the hangar and 'the engine and all materials' were delivered, and on pps. 14 and 125 that his 'partner and friend Stanislaw Cywinski did not hold out to the end' in construction of the aircraft. According to p. 20, the building of the machine was finished in the early autumn of 1910, the first unofficial test took place in the autumn of 1910, and the first official test, in public, in the summer of 1911.
  So much for Zbieranski's post-war revelations; now let us look at facts. The 'first demonstration in Poland of a heavier-than-air machine and its attempts at flight' took place on 15-19 September, 1909, the pilot and aircraft involved being Georges Legagneux on a Voisin biplane (the second was Baron de Caters also on a Voisin), and not Guyot. Guyot displayed his Bleriot in Warsaw only at the beginning of April 1910, and even borrowed the Anzani engine from Tanski, because his own engine developed trouble (see contemporary press reports in Swiat, Kurier Warszawski, Lotnik i Automobilista, etc). Even if it could be accepted that Zbieranski forgot the name of the pilot and had the first demonstration in mind, the meeting of the Circle was held some time after that and later Zbieranski went abroad.
  This means that the study for the aircraft proposed by him could have been conceived only in the winter of 1909-10 at the earliest (by which time Tanski, Libanski and other Polish pioneers were already hard at work on their aeroplanes). Then Zbieranski went abroad again to examine more aircraft and search for materials (to France and Germany), which had to be delivered to Warsaw, and this took time. It took him 'a few months' to build the fuselage at the Solec Street shed. In fact he could not possibly have moved to Aviata earlier than September 1910, because the hangars had not been finished. Tanski was offered accommodation in one of the hangars as soon as they were ready and moved in without delay on 8 October, 1910. By this date only two of the eight hangars were occupied, one of them, No. 1, by Zbieranski. and these apparently went into use only a few weeks, if not days, earlier. Writing to his son Tadeusz, who was studying in France, Tanski said in a letter of 9 October. 1910: 'Zbieranski is doing absolutely nothing, he has no room and no money for the engine'; and later, in a letter dated 10 November, 1910: 'At Zbieranski's (hangar) work is going on in spite of the cold, Cywinski works most.' This contemporary private correspondence establishes three points: that in the late autumn of 1910 the Zbieranski and Cywinski biplane was far from being ready; its designers were still without the engine; and Cywinski was working on the airframe before he went for the engine.
  While Cywinski was alive (he was killed by a German shell in September 1939, while fighting the fires of burning Warsaw), Zbieranski described his participation in the project rather differently. During an interview with a reporter from Ilustrowany Kurier Codzienny, published on 17 July, 1938, he stated: 'As a partner and companion in my work I invited Ing Stanislaw Cywinski. We had great difficulties in our work, because the price of materials which were not yet on the market, or not even in existence, could not be estimated... The whole of the aircraft was made with my own and Cywinski's funds.' This clearly proved that Cywinski was closely associated with the development of the project before Zbieranski purchased the steel tubes from Deutz and before the actual construction of the machine began. That the financial considerations in inviting Cywinski 'as a partner' were not the only ones becomes apparent from the fact that towards the middle of 1910 Zbieranski bought for himself the Bleriot Type No. XI monoplane, which was previously used by Pierre Grand, the French pilot giving flying demonstrations in Poland.
  Stefan Kozlowski, designer of the first Polish aircraft to leave the ground, in Warsaw, wrote as follows to the author of this work on 30 January, 1961: 'Ing Cywinski visited me in my hangar a few times (in the late spring of 1910) bringing with him some drawings of his aircraft project; we discussed this subject and I shared with him the experience which I had already acquired in this field. It looked to me as if he was evolving the design alone. At this period I did not know Zbieranski.' Similar statements were made by members of the Cywinski family and his surviving friends, who confirmed that Cywinski was passionately absorbed in the preparation of the design and drawings for the biplane, on which he apparently worked alone.
  In view of these conflicting statements, the question as to who was really the designer of the biplane will presumably always remain a matter of controversy. However, while it is possible that the initiative to develop the aircraft and its initial sketches did originate with Zbieranski, a businessman who throughout his life showed great interest in various engineering enterprises, there can be no reasonable doubt that Cywinski, who remained an aircraft designer until his death, was involved in the project right from its inception and played a substantial and vital part in the development of the design. The available evidence also establishes that the project was evolved in the spring of 1910, the fuselage built at Solec Street in the summer, presumably during June-September 1910, and the machine completed about a year later, in the spring of 1911.
  Zbieranski mentioned more than once in his book the 'unofficial' flight attempt, but discreetly omitted the identity of the pilot involved and any details regarding the results of the trial. In fact, the test, which presumably took place in May 1911 (according to Zbieranski, after the Lodz Aviation Exhibition, where his E.N.V. engine was shown), was made by none other than Stanislaw Cywinski. There are confused reports as to what really happened during that attempt, Zbieranski disclosing only that the biplane 'received minor damage because of a fire which resulted from faulty connection of the cables'. A number of eye witness reports (including the testimony of Karol Milobedzki, prepared specifically for Zbieranski's book and printed there on p. 27) clearly indicated that the aircraft made on that occasion a short flight which ended in a minor mishap. Again, contrary to Zbieranski's statements (pps. 14 and 125), the fact "that Cywinski worked on the machine right until its final completion and test is beyond dispute. Indeed, Zbieranski himself, somewhat shattered by the hot reception which his book received in Poland, admitted this in his article in Skrzydlata Poiska in 1960 (Nos. 43 and 44).
  The first wholly successful flight of the Zbieranski and Cywinski biplane was carried out from Mokotow aerodrome by one of the best-known and respected pilots, Michal Scipio del Campo. According to Zbieranski this unfortunate take-off for Moscow' and his aircraft thus became 'the second flying prototype of steel in Europe and the first Polish aeroplane to meet all the principles required from the heavier-than-air machine, i.e. which could freely take-off from the ground and be freely controlled by man in the air' (p. 23). It is easy to establish from the study of contemporary materials that 'Scipio del Campo's unfortunate flight' (to Petersburg and not to Moscow) began on 26 September, 1911. The Zbieranski and Cywinski aircraft was therefore tested on 25 September (in any case Scipio del Campo began to fly in Warsaw only on 13 August, 1911, and this test was made some weeks later).
  Apart from the Polish designs evolved abroad (Warchalowski Wrobel), the Zbieranski and Cywinski biplane was not the first Polish aeroplane to make a sustained and controlled flight. Libanski's Jaskolka, built in Lwow and tested in Wiener-Neustadt, successfully flew in August 1911, and the Glowinski monoplane, built and flown in Tarnopol, achieved a similar distinction sometime in the spring of 1911. Sensing the challenge to his claim from the Jaskolka, Zbieranski eliminated it with an astonishing fabrication that the machine was the work of 'an Austrian' (see Jaskolka). The Glowinski monoplane was not favoured with any mention in his book. Furthermore, the biplane was not 'of steel', but of composite construction, only its fuselage being of steel tubing, and this was not uncommon (Libanski built a steel fuselage a year earlier).
  The September flight of the Zbieranski and Cywinski biplane was a complete success. The machine circled Mokotow aerodrome four times, covering a distance of 15-20 km (9.3-12.4 miles) at a height of 50-60 m (164-197 ft) and achieving a speed of about 70 km/h (43.5 mph). Michal Scipio del Campo described the test as 'exceeding his expectations'. The biplane 'took-off at the first attempt, was manoeuvrable, fast, and docile in landing. It had ... some minor, easily curable, shortcomings, i.e. indicated a tendency to drop its nose. Its main fault was the unsuitable engine, too heavy and weak for its own and the aircraft's weight.' As the designers did not have another powerplant, Scipio del Campo offered to lend the 50 hp Gnome rotary from his Morane monoplane. The engine was installed in the biplane, but Scipio del Campo recollected: 'circumstances beyond my control prevented me from making a test flight with this new engine... This I regret even now, as results could have been outstanding.'
  In the autumn of 1911, because of misunderstandings arising from financial arrangements, and presumably also from disagreements regarding the use of the aircraft (Cywinski, inexperienced as a pilot, was believed to have been stopped by Zbieranski from further flight attempts), Cywinski decided to withdraw from the partnership. As Zbieranski was unable to repay Cywinski's share, the latter accepted the E.N.V. engine, which he sold to someone for installation in a motorcar. Towards the end of the year the Aviata factory required its hangar No. 1 for its own use and asked Zbieranski to vacate it. Having nowhere to go, Zbieranski offered his aircraft to ZASPL and in 1912, at ZASPL initiative, the engineless machine was transported by rail from Warsaw to Krakow. The biplane was displayed in Krakow for a long time in order to raise funds for its upkeep and transport to Lwow. However, it never left Krakow and was completely burned out in the first days of World War 1 when the building in which it was stored was accidentally set on fire.
  The aircraft in question was outstandingly advanced in overall concept and design and the most successful among the machines constructed in Poland at that time. It was also the first Polish aircraft to achieve a fully sustained and controlled flight in Poland's capital city. On these grounds it should have a lasting place in the history of Polish aviation.
  In view of the conflicting evidence as to who really designed the biplane, any honest historian must allot the credit equally between Cywinski and Zbieranski. The author decided to retain the designation 'Zbieranski and Cywinski Biplane', as this was used in most contemporary publications, Zbieranski's name being then mentioned first because of his handling of all commercial transactions (such as purchases of materials, hiring of the shed and hangar, etc) associated with the building of the machine.

Construction: The Zbieranski and Cywinski aircraft was a single-seat unequal-span two-bay biplane of composite construction. The wings, with a total area of 31 sq m (333.7 sq ft), were conventional wooden frameworks of double-surfaced type, and the interplane struts were of steel tubing. The lower wing, with a span of 9 m (29 ft 6 3/4 in), featured slight dihedral, the interplane gap reducing from 1.85 m (6 ft 1 1/4 in) in the centre to 1.6 m (5 ft 3 1/4 in) at the tip. Chord of the top wing was 1.75 m (5 ft 9 in) and of the lower wing 1.6 m (5 ft 3 1/4 in). Ailerons were fitted only to the upper wing. The open fuselage frame, of triangular section, was built up of cold-drawn steel tubes, the smaller diameter tubes being filled with solid wood for strength. No welding was used, the whole frame being assembled with the help of connecting joints and steel screws. The pilot's position, behind the engine, was provided with a conventional control stick and rudder bar. The tail unit, of biplane configuration and structure similar to that of the wings, embodied full-chord tip elevators and twin rudders. The landing gear, incorporating special rubber shock-absorbers, consisted of two wheels and two skids, the skids being lowered on first contact of the wheels with the ground and supporting the machine during landing. Power was supplied by the E.N.V. Type D eight-cylinder upright vee water-cooled engine developing 40 hp at 1,700 rpm and driving the 2.25 m (7 ft 4 3/4 in) diameter Chauviere airscrew. The whole airframe could easily be dismantled into four major sections for transport. Dimensions included a span of 10 m (32 ft 9 3/4 in) and length of 8.5 m (27 ft 11 in). The loaded weight was 340 kg (749 lb).

C.Jerzy - Polish Aircraft 1893-1939 /Putnam/
Zbieranski and Cywinski biplane, ihe most promising machine among early aircraft constructed in Poland, which successfully flew in September 1911.