The Junak is a Polish trainer aircraft, used from 1952 to 1961 by the Polish Air Force and until 1972 by Polish civilian operators. It was designed in the LWD bureau and produced in the WSK Warszawa-Okęcie factory.
The aircraft was designed in response to a Polish Air Force requirement of 1946 for a trainer to replace the Soviet UT-2, which was obsolete. The new aircraft was designed in 1947 in the LWD (Lotnicze Warsztaty Doświadczalne - Aircraft Experimental Workshops) - the first Polish post-war construction bureau. The chief designer was Tadeusz Sołtyk. A prototype named the LWD Junak, later the Junak 1, was flown on February 22, 1948 (its name means "brave young man"). The entire design was Polish, except for the engine, which was a license-built Soviet radial, the Shvetsov M-11D (93 kW, 125 hp).
After tests, an improved variant, the Junak 2 was flown on July 12, 1949. Notable changes from the Junak 1 included the cockpit being moved forward, the fin being increased in area, a more powerful M-11FR engine (118 kW, 160 hp) was fitted and the massive landing gear covers were deleted. The plane's handling improved. The LWD team disbanded in 1950 and Junak 2 development was continued by the CSS workshops in Warsaw. After further improvements the prototype was designated the Junak-2bis, but finally entered production in 1951 as the Junak-2. Tadeusz Sołtyk was given a State Award in 1952 for the design. From 1951 to 1954, 105 Junak 2s were produced in the WSK-Okęcie in Warsaw (the first 3 in the WSK-Mielec).
LWD may refer to:
Logging while drilling (LWD) is a technique of conveying well logging tools into the well borehole downhole as part of the bottom hole assembly (BHA).
LWD tools work with its measurement while drilling (MWD) system to transmit partial or complete measurement results to the surface via typically a drilling mud pulser or other improved techniques, while LWD tools are still in the borehole, which is called "real-time data". Complete measurement results can be downloaded from LWD tools after they are pulled out of hole, which is called "memory data".
LWD, while sometimes risky and expensive, has the advantage of measuring properties of a formation before drilling fluids invade deeply. Further, many wellbores prove to be difficult or even impossible to measure with conventional wireline tools, especially highly deviated wells. In these situations, the LWD measurement ensures that some measurement of the subsurface is captured in the event that wireline operations are not possible. Timely LWD data can also be used to guide well placement so that the wellbore remains within the zone of interest or in the most productive portion of a reservoir, such as in highly variable shale reservoirs.