PZL Bielsko SZD-6x
Encyclopedia
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The SZD-6x Nietoperz was a single-seat tail-less experimental glider aircraft
that was designed and built in Poland
at Szybowcowy Zakład Doświadczalny
(Glider Experimental Works) in Bielsko-Biała
in 1951. Only one example was constructed (with registration SP-1220).
, and placed the pilot at the centre of gravity, so that differing pilot weights had little impact on stability.
The first 'hop' was made on 5 January 1951 at Bielsko
to test control effectiveness and stability. For more comprehensive trials the glider was transported to Katowice
airfield which suffered less turbulence from high ground. On 12 January 1951, the pilot Adam Zientek took an exploratory aero-tow behind a PWS-26
piloted by T. Hill, which nearly ended in disaster. The SZD-6x suffered PIOs (pilot induced oscillations) while still at low altitude over the airfield, hit the ground hard and was damaged. The first "real" flight took place on 2 February 1951, flown by A. Zientek. Later flights were completed successfully, but all the pilots agreed that the aircraft was not suitable for production due to inherent control problems.
The control system of the SZD-6x was designed to allow the aircraft to be flown with several different control configurations. The trailing edges of the wings carried three surfaces each, all of which could be linked to form elevons or operated individually as ailerons, elevators or flaps. The metal-skinned split ailerons also formed the airbrakes
, opening out to give increased drag. The ailerons/airbrakes could be connected to the rudder pedals to be used as drag rudders, similar to the drag rudders used on the Northrop
flying wings. The controls were tested in three configurations:
The prototype was used in the SZD for experimental purpose between 18 April 1952 and 26 February 1964, and it also took part in several air shows, even performing aerobatics
.. With the interesting flying characteristics of the SZD-6x most pilots were not keen to fly the aircraft but Adam Zientek persevered for some time before the aircraft was retired to the Kraków Aviation Museum in 1964.
The SZD-6x Nietoperz was a single-seat tail-less experimental glider aircraft
Glider aircraft
Glider aircraft are heavier-than-air craft that are supported in flight by the dynamic reaction of the air against their lifting surfaces, and whose free flight does not depend on an engine. Mostly these types of aircraft are intended for routine operation without engines, though engine failure can...
that was designed and built in Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
at Szybowcowy Zakład Doświadczalny
Szybowcowy Zakład Doświadczalny
Szybowcowy Zakład Doświadczalny , Glider Experimental Works was a glider design and research centre of the Polish aerospace industry after World War II, located in Bielsko-Biała. Through its history it underwent many organizational and name changes, among others in 1946-1948 it was Instytut...
(Glider Experimental Works) in Bielsko-Biała
Bielsko-Biała
-Economy and Industry:Nowadays Bielsko-Biała is one of the best-developed parts of Poland. It was ranked 2nd best city for business in that country by Forbes. About 5% of people are unemployed . Bielsko-Biała is famous for its textile, machine-building, and especially automotive industry...
in 1951. Only one example was constructed (with registration SP-1220).
Development
The SZD-6x Nietoperz (Bat) was designed and built to research tail-less aircraft, and the control of them. Main designers were Władysław Nowakowski and Justyn Sandauer. Built in a conventional fashion using wood throughout, fabric covering and steel for highly stressed parts and fittings the SZD-6x was a cantilever monoplane with the cranked wing attached to a short fuselage pod at the mid position. The inner portion of each wing was markedly swept forward out to approx. quarter-span, where the swept-back outer wing panels were attached. This is arrangement allowed for maximum distance between the centre of gravity and the vertical stabilizerVertical stabilizer
The vertical stabilizers, vertical stabilisers, or fins, of aircraft, missiles or bombs are typically found on the aft end of the fuselage or body, and are intended to reduce aerodynamic side slip. It is analogical to a skeg on boats and ships.On aircraft, vertical stabilizers generally point upwards...
, and placed the pilot at the centre of gravity, so that differing pilot weights had little impact on stability.
The first 'hop' was made on 5 January 1951 at Bielsko
Bielsko
Bielsko was until 1950 an independent town situated in Cieszyn Silesia, Poland. In 1951 it was joined with Biała Krakowska to form the new town of Bielsko-Biała. Bielsko constitutes the western part of that town....
to test control effectiveness and stability. For more comprehensive trials the glider was transported to Katowice
Katowice
Katowice is a city in Silesia in southern Poland, on the Kłodnica and Rawa rivers . Katowice is located in the Silesian Highlands, about north of the Silesian Beskids and about southeast of the Sudetes Mountains.It is the central district of the Upper Silesian Metropolis, with a population of 2...
airfield which suffered less turbulence from high ground. On 12 January 1951, the pilot Adam Zientek took an exploratory aero-tow behind a PWS-26
PWS-26
-References:*Andrzej Glass: "Polskie konstrukcje lotnicze 1893-1939" , WKiŁ, Warsaw 1977 -See also:...
piloted by T. Hill, which nearly ended in disaster. The SZD-6x suffered PIOs (pilot induced oscillations) while still at low altitude over the airfield, hit the ground hard and was damaged. The first "real" flight took place on 2 February 1951, flown by A. Zientek. Later flights were completed successfully, but all the pilots agreed that the aircraft was not suitable for production due to inherent control problems.
The control system of the SZD-6x was designed to allow the aircraft to be flown with several different control configurations. The trailing edges of the wings carried three surfaces each, all of which could be linked to form elevons or operated individually as ailerons, elevators or flaps. The metal-skinned split ailerons also formed the airbrakes
Air brake (aircraft)
In aeronautics, air brakes or speedbrakes are a type of flight control surface used on an aircraft to increase drag or increase the angle of approach during landing....
, opening out to give increased drag. The ailerons/airbrakes could be connected to the rudder pedals to be used as drag rudders, similar to the drag rudders used on the Northrop
Northrop Corporation
Northrop Corporation was a leading United States aircraft manufacturer from its formation in 1939 until its merger with Grumman to form Northrop Grumman in 1994. The company is known for its development of the flying wing design, although only a few of these have entered service.-History:Jack...
flying wings. The controls were tested in three configurations:
- with pitch and roll control provided by all four elevons, and yaw controlled by the rudder. In this configuration the aircraft proved to be stable in pitch, being able to be flown hands-off during aero-tow, and pitch controlled simply by the pilot leaning forwards or backwards to adjust the centre of gravity. Lateral stability was noted to be poor to fair but acceptable and the aircraft was safe and capable of flying simple aerobatics.
- as above for pitch and roll, but with the rudder locked and the pedals operating the airbrakes differentially for yaw, lateral control prove barely adequate.
- the rudder fixed in place. This configuration was inherently dangerous as any application of ailerons gave instant adverse yaw, and pitch and roll in the opposite direction to that intended.
The prototype was used in the SZD for experimental purpose between 18 April 1952 and 26 February 1964, and it also took part in several air shows, even performing aerobatics
Aerobatics
Aerobatics is the practice of flying maneuvers involving aircraft attitudes that are not used in normal flight. Aerobatics are performed in airplanes and gliders for training, recreation, entertainment and sport...
.. With the interesting flying characteristics of the SZD-6x most pilots were not keen to fly the aircraft but Adam Zientek persevered for some time before the aircraft was retired to the Kraków Aviation Museum in 1964.
Specifications
External links
- http://www.piotrp.de/SZYBOWCE/pszd6.htm
- http://en.wikipedia.org/wiki/Polish_Aviation_Museum