PZL (Państwowe Zakłady Lotnicze - State Aviation Works) was the main Polish aerospace manufacturer of the interwar period, based in Warsaw, functioning in 1928-1939. The abbreviation was thereafter - from late 1950s - used as an aircraft brand and as a part of names of several Polish state-owned aerospace manufacturers referring to traditions of the PZL, belonging to the Zjednoczenie Przemysłu Lotniczego i Silnikowego PZL - PZL Aircraft and Engine Industry Union.