The prototype was constructed using parts of a broken up RWD 6 (initially it was even supposed to be designated RWD 6bis), but its construction was more similar to newer RWD 9. It first flew on 15 January 1935 (registration SP-AOA). Since the RWD 13 was not supposed to be a competition aircraft, the main differences from the RWD 9 were: an inline engine with lower power output, instead of a radial engine, and simpler wing mechanization. It still had advantages, like short take-off and landing and ease of flying, with good stability. By 1939, some 85 were produced.