| Medwecki HL 2 | |
|---|---|
 | |
| Role | Light aircraft |
| National origin | Poland |
| Designer | Jozef Medwecki |
| First flight | September 1927 |
| Number built | 1 |
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.
A light aircraft is an aircraft that has a maximum gross takeoff weight of 12,500 lb (5,670 kg) or less.
Light aircraft design was slow to start in Poland but from 1924 the Airborne and Antigas Defence League, generally known by their Polish acronym L.O.P.P., began to fund amateur builders. One of the first successful bidders was Jozef Medwecki, an aircraft designer with the Samolot company. The result was the HL 2 two-seater which Medwecki built, with Samolot's approval, in their factory in his spare time. It was finished in August 1927. [1]
Air and Chemical Defense League was a mass Polish paramilitary organization, founded in 1928 and based on the previous organization, Air Defense League of the Country. In 1937 it numbered some 1.5 million members, with 14,000 local branches. It had a national character, gathering enthusiasts of aircraft, communications and ballooning. Between 1928 and 1939, its director was general Leon Berbecki
Samolot was the Polish aerospace manufacturer, located in Poznań and active between 1924 and 1930. It manufactured among others aircraft under the Bartel name. The name Samolot itself means airplane in Polish.
The HL 2 had a parasol wing with a quite thick section and a plan that was strictly rectangular apart from a central trailing edge cut-out to improve the pilot's field of view. The wing was in two parts, built around pairs of wooden spars and ply-covered. It was supported over the fuselage on cabane struts, one leaning back from the upper central fuselage to the forward strut and the other a vertical inverted V-strut to the rear spar; the principal bracing members were parallel steel tubes from the lower fuselage longerons to the spars. [1]
The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge rejoins. Essential flight control surfaces are attached here to control the direction of the departing air flow, and exert a controlling force on the aircraft. Such control surfaces include ailerons on the wings for roll control, elevators on the tailplane controlling pitch, and the rudder on the fin controlling yaw. Elevators and ailerons may be combined as elevons on tailless aircraft.
In a fixed-wing aircraft, the spar is often the main structural member of the wing, running spanwise at right angles to the fuselage. The spar carries flight loads and the weight of the wings while on the ground. Other structural and forming members such as ribs may be attached to the spar or spars, with stressed skin construction also sharing the loads where it is used. There may be more than one spar in a wing or none at all. However, where a single spar carries the majority of the forces on it, it is known as the main spar.
Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured boards which includes medium-density fibreboard (MDF) and particle board (chipboard).
Medwecki's greatest problem was to obtain a suitable engine and in the end had to settle for an elderly, three-cylinder 26 kW (35 hp) Anzani lent to him by Samolot, which left the HL 2 seriously underpowered. It was installed in a simple, flat-sided metal cowling with its cylinder heads exposed for cooling. The cowling widened rearwards to match the dimensions of the HL 2's simple, rectangular section fuselage which was built around four wooden longerons and ply covered. Behind the fuel tanks the open cockpits were in tandem and fitted with dual control. The forward one was under the wing and was entered via a car-type door with a special lock to insure integrity of the upper longeron and the rear one, conventionally entered, was under the trailing edge cut-out. [1]
From 1905 to 1915, Alessandro Anzani built a number of three-cylinder fan and radial engines, one of which powered Louis Blériot's 1909 cross-channel flight. An Anzani three-cylinder engine that powers a Blériot XI based in England is thought to be the oldest airworthy engine in the world.
In engineering, a longeron 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 frameworks.
A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a pilot controls the aircraft.
The HL 2's strut-braced tailplane was mounted on top of the fuselage and, like the elevators, was essentially rectangular in plan. The fin was triangular and carried a rectangular rudder. Its fixed undercarriage had mainwheels on a single axle with rubber cord shock absorbers and supported at each end by a V-strut to the lower fuselage longeron. There was a short tailskid under the fin. [1]
A tailplane, also known as a horizontal stabiliser, is a small 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 and gyroplanes. Not all fixed-wing aircraft have tailplanes. Canards, tailless and flying wing aircraft have no separate tailplane, while in V-tail aircraft the vertical stabiliser, rudder, and the tail-plane and elevator are combined to form two diagonal surfaces in a V layout.
Elevators are flight control surfaces, usually at the rear of an aircraft, which control the aircraft's pitch, and therefore the angle of attack and the lift of the wing. The elevators are usually hinged to the tailplane or horizontal stabilizer. They may be the only pitch control surface present, and are sometimes located at the front of the aircraft or integrated into a rear "all-moving tailplane", also called a slab elevator or stabilator.
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other conveyance that moves through a fluid medium. On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane. A rudder operates by redirecting the fluid past the hull (watercraft) or fuselage, thus imparting a turning or yawing motion to the craft. In basic form, a rudder is a flat plane or sheet of material attached with hinges to the craft's stern, tail, or after end. Often rudders are shaped so as to minimize hydrodynamic or aerodynamic drag. On simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, cables, pushrods, or hydraulics may be used to link rudders to steering wheels. In typical aircraft, the rudder is operated by pedals via mechanical linkages or hydraulics.
The HL 2 made its first flights in September 1927 from Samolot's home ground of Poznan-Lawica, flown by Wladyslaw Szulczewski. Despite the lack of power it was capable of aerobatics. It was entered as a competitor in the L.O.P.P.-organised First National Lightplane Contest held at the start of October in Warsaw but engine problems on the way there caused it to fail to meet the deadline. Nonetheless, Szulczewski took part as an unofficial contestant and at first its performance was outstanding but during a cross-country flight the engine failed again. The HL 2 was seriously damaged in the consequent emergency landing and never flew again. [1]
Warsaw is the capital and largest city of Poland. The metropolis stands on the Vistula River in east-central Poland and its population is officially estimated at 1.78 million residents within a greater metropolitan area of 3.1 million residents, which makes Warsaw the 8th most-populous capital city in the European Union. The city limits cover 516.9 square kilometres (199.6 sq mi), while the metropolitan area covers 6,100.43 square kilometres (2,355.39 sq mi). Warsaw is an alpha global city, a major international tourist destination, and a significant cultural, political and economic hub. Its historical Old Town was designated a UNESCO World Heritage Site.
Data from Cynk (1971) [1] except where noted
General characteristics
Performance
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