LOT Polish Airlines Flight 7 increased engine wear, since the engines were under greater load. NK-8-4 engines were not reliable enough. Warranty service life was only 5000 hours, and about half of LOT engines failed after 2000–3000 hours. Because of this, Polish pilots often called the Il-62 "flying coffins". In spite of the low reliability, the airline decided to increase overhaul life intervals to reduce the frequency of repairs, which were carried out in Soviet factories and quite expensive. LOT sent a letter to the Ilyushin Design Bureau containing the results of a test in which it was found that the engines could operate normally
Polish Operation of the NKVD of the Polish diversionist and espionage groups and POW units"," was approved on August 9, 1937 by the Party's Central Committee Politburo, and was signed by Nikolai Yezhov on August 11, 1937. It was distributed to the local subdivisions of the NKVD simultaneously with Yezhov's thirty-page "secret letter," explaining what the "Polish operation" was all about. The letter from Yezhov was titled, ""On fascist-resurrectionist, spying, diversional, defeationist, and terrorist activity of Polish intelligence in the USSR"". Stalin demanded the NKVD to "keep on digging out and cleaning out this Polish filth." The "Order" adopted the simplified so-called "album procedure" (as