Mustafa Seydulayevich Chachi (Russian: Мустафа Сейдулаевич Чачи; 25 May 1935 – 15 February 1970) was the director of the 5th division of the "Five-Year Plan of the Uzbek SSR" sovkhoz[1] in Oqqoʻrgʻon District of Tashkent region, Uzbek SSR, and an innovator of organizing productive labor and implementing new methods.
He was awarded the title of Hero of Socialist Labor in 1966 and was one of the signatories of the notorious letter of seventeen telling other Crimean Tatars to give up dreams of returning to Crimea.
[3] By the decree of the Presidium of the Supreme Soviet of the USSR on 30 April 1966, Mustafa Chachi was awarded the Order of Lenin and the “Hammer and Sickle” gold medal and the title of Hero of Socialist Labor for his achievements in increasing cotton production and silkworm breeding.
[4] Mustafo Chachi's experience of efficient labor was studied by visitors from all over the Soviet Union, as well as from foreign countries.
At the end of the 1960s, when the Crimean Tatars were allowed to move more freely throughout the country, he signed the notorious and widely criticized letter of seventeen in March 1968 that encouraged other Crimean Tatars from giving up their dreams of returning to Crimea and avoid succumbing to "provocations" encouraging them to return, and claimed that the real tragedy would be leaving the Uzbek SSR.