who is responsible for the design?
Sydney Camm
Hawker Hart
 was designed during the 1920s by Sydney Camm and manufactured by Hawker Aircraft. 
what does the term "hawker hurricane in yugoslav service" mean? The ser vice of Hawker Hurricane Mk I fighters in Royal Yugoslav Air Force. when was it established? UNANSWERABLE were these aircrafts made by the royal yugoslav? No, by Hawker Aircraft Ltd. which country does this company belong to? Britain. what else do they manufacture? Hawker Hind and the Hawker Hart. what is the former? A British light bomber. and the second? A British two-seater biplane light bomber aircraft.
wiki:20190084
Hawker Hart [SEP] Introduction
The Hawker Hart was a British two-seater biplane light bomber aircraft of the Royal Air Force (RAF). It was designed during the 1920s by Sydney Camm and manufactured by Hawker Aircraft. The Hart was a prominent British aircraft in the inter-war period, but was obsolete and already side-lined for newer monoplane aircraft designs by the start of the Second World War, playing only minor roles in the conflict before being retired. Several major variants of the Hart were developed, including a navalised version for the Royal Navy's aircraft carriers. Beyond Britain, the Hart would be operated by a number of foreign nations, including Sweden, Yugoslavia, Estonia, South Africa, and Canada.