"We know well of An-2 Annushka, but, it has a sibling An-3, that's less known. An-2 flew in Aug 1947, and the An-3 (though numerically designated just "1+") flew 33 years later, in May 1980. So, although it is designated An-3, this number was not assigned in chronological sequence. Antonov assigned "-3" designation to the plane because it was meant to replace the An-2. It was possible to assign "-3" to this plane, because, in the serial list of Antonov aircraft, after An-2, appear An-6 (Maiden flight 1948) and An-4 (Maiden flight 1951) i.e. An-3 designation was skipped and left unfulfilled, an
