The Działowski D.K.D.1 was the first powered aircraft designed by . It was a low-power

high-wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple wings. A monoplane has inherently the highest efficiency and lowest drag of any wing config ...

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple wings. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

with a cabin for one passenger. After attending an aviation exhibition in

Warsaw Warsaw, officially the Capital City of Warsaw, is the capital and List of cities and towns in Poland, largest city of Poland. The metropolis stands on the Vistula, River Vistula in east-central Poland. Its population is officially estimated at ...

in 1927 it was badly damaged when the engine failed as it left and it did not fly again.

Design and development

In the early 1920s Stanisław Działowski was head of aircraft assembly at the military flying school at

Bydgoszcz Bydgoszcz is a city in northern Poland and the largest city in the historical region of Kuyavia. Straddling the confluence of the Vistula River and its bank (geography), left-bank tributary, the Brda (river), Brda, the strategic location of Byd ...

. He and his brother Mieczysław began aircraft design with a glider, the Bydgoszczanka, which flew at the 1925 Second Polish Glider Contest. In the same year they began work on the D.K.D.1. The surname initials D.K.D were those of the two brothers and of Jan Kruger, a local shoemaker who provided some funding and also bought the Gabriel brothers the Haacke engine that had been used in the Gabriel P 5 and P 6. The wing was built in the military workshop but they were later forced out to a cellar in the town. The D.K.D.1 was a high wing aircraft with an enclosed cabin for one passenger and an 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 ...

for the pilot. It had a one-piece wooden wing of trapezoidal plan with an unswept

leading edge The leading edge is the part of the wing that first contacts the air;Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, 1997. alternatively it is the foremost edge of an airfoil sectio ...

, built around two

spars SPARS was the authorized nickname for the United States Coast Guard (USCG) Women's Reserve. The nickname was derived from the USCG's motto, "—"Always Ready" (''SPAR''). The Women's Reserve was established by law in November 1942 during Wor ...

and fabric covered. The wing was braced with V-struts from the lower fuselage

longeron In engineering, a longeron or stringer is a load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural fram ...

s to the spars. The aircraft first flew with the wing centrally fixed directly to the top of the fuselage but flight testing revealed poor forward visibility from the cockpit and the wing was raised a short distance on four vertical, faired

strut A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. A stay is sometimes used as a synonym for ...

s, allowing the pilot to look forward under the wing. There was a large, deep cut-out in the

trailing edge The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 1997. ...

over the cockpit. The generous balances on its

ailerons An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

extended beyond the squared wing tips. The D.K.D.1 was powered by a Haacke HFM-2 air-cooled flat twin engine mounted onto the rectangular section steel tube fuselage frame under single-curvature

duralumin Duralumin (also called duraluminum, duraluminium, duralum, dural(l)ium, or dural) is a trade name for one of the earliest types of age hardening, age-hardenable aluminium–copper alloys. The term is a combination of ''Düren'' and ''aluminium'' ...

sheet, with its cylinder heads exposed for cooling. Behind it the deep, flat-sided fuselage was fabric covered apart from its rounded,

plywood Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboa ...

covered decking. The enclosed, single seat passenger cabin was immediately behind the engine and ahead of the cockpit. It had a small window on each side and was entered by a port-side door. Both

fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. F ...

and

tailplane A tailplane, also known as a horizontal stabilizer, is a small lift (force), lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters ...

, the latter located on top of the fuselage, were small and rectangular in shape, mounting large, balanced control surfaces. These were also approximately rectangular but the bottom of the rudder was cut at an angle to allow the one-piece

elevator An elevator (American English) or lift (Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems suc ...

to operate. All the rear surfaces were wooden framed and fabric covered. Its

undercarriage Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include: *The landing gear of an aircraft. *The ch ...

was fixed and of the tailskid type, with mainwheels with rubber cord shock absorbers on a single axle. The axle was mounted on short steel tube V-struts hinged from the lower fuselage longerons, with further steel struts from both the longerons and central fuselage underside to the axle's centre.

Operational history

The D.K.D.1 first flew in February 1926, piloted by Muślewski and the early tests led to the raising of the wing noted above and to other changes to the centre-section. Its designer also flew it and in late April 1927 took it to an aviation exhibition held in Warsaw. His , bad weather leg from

Toruń Toruń is a city on the Vistula River in north-central Poland and a World Heritage Sites of Poland, UNESCO World Heritage Site. Its population was 196,935 as of December 2021. Previously, it was the capital of the Toruń Voivodeship (1975–199 ...

to Warsaw has been reported as "the first long cross-country flight to be made on a Polish-designed lightplane". Their earlier base at Bydgodaszcz had become unreceptive to civilian flying but another regiment at

Kraków , officially the Royal Capital City of Kraków, is the List of cities and towns in Poland, second-largest and one of the oldest cities in Poland. Situated on the Vistula River in Lesser Poland Voivodeship, the city has a population of 804,237 ...

was much more sympathetic, so he attempted to take the D.K.D.1 there. Early in the flight the old Haacke engine failed and the D.K.D.1 was badly damaged in the emergency landing. Its remains were taken to Kraków and parts of it were used in the group's next aircraft, the D.K.D.3.

Specifications

References

{{reflist, refs= {{cite book, title=Polish Aircraft 1893-1939, last=Cynk, first=Jerzy, year=1971, publisher=Putnam Publishing, location=London, isbn=0-370-00085-4, pag
600-602
url-access=registration, url=https://archive.org/details/polishaircraft1800cynk/page/600 Cynk (1971 pp.678-80 {{cite journal , last=Kaftal , first=André , date=9 May 1927, title=L'exposition de Varovie, journal=Les Ailes, issue=309, pages=9, url=http://gallica.bnf.fr/ark:/12148/bpt6k6568341h/f1 {{cite web , url=http://www.samolotypolskie.pl/samoloty/844/126/DKD-I2, title=DKD-2, 1926 , access-date=21 December 2017 Single-engined tractor aircraft High-wing aircraft 1920s Polish sport aircraft Aircraft first flown in 1926