PWS-10
...that PWS-10 designed in late 1920s was the first Polish fighter to enter serial production?
...that <b id="mwjQ"><a href="./PWS-10" id="mwjg" rel="mw:WikiLink" title="PWS-10">PWS-10</a></b> designed in late <a href="./1920s" id="mwjw" rel="mw:WikiLink" title="1920s">1920s</a> was the first <a href="./Second_Polish_Republic" id="mwkA" rel="mw:WikiLink" title="Second Polish Republic">Polish</a> <a href="./Fighter_aircraft" id="mwkQ" rel="mw:WikiLink" title="Fighter aircraft">fighter</a> to enter serial production?