which organization used this aircraft?
Royal Egyptian Air Force and Royal Indian Air Force.
Hawker Hart
The Hart proved to be a successful export, seeing service with the Royal Egyptian Air Force, Royal Indian Air Force, South African Air Force, Estonian Air Force, Southern Rhodesia, Sweden (where it was designated B4) and the Kingdom of Yugoslavia. 
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. who is responsible for the design? Sydney Camm when ? During the 1920s.
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Hawker Hart [SEP] Operational history
Though obsolete compared to the United Kingdom's opposition at the start of the Second World War, the Hart continued in service, mainly performing in the communications and training roles until being declared obsolete in 1943. The Hart proved to be a successful export, seeing service with the Royal Egyptian Air Force, Royal Indian Air Force, South African Air Force, Estonian Air Force, Southern Rhodesia, Sweden (where it was designated B4) and the Kingdom of Yugoslavia. The Rhodesian Hardys saw service on the Allied side during the opening moves of the East African theatre of World War II.