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
LOT Polish Airlines Flight 5055 involving an Ilyushin Il-62, and to date, it remains the deadliest aviation crash in Polish history. It was determined to have been caused by the disintegration of an engine shaft due to faulty bearings. The aircraft was a 186-seat Ilyushin Il-62M built in the third quarter of 1983, registered SP-LBG and named "Tadeusz Kościuszko", after the Polish military leader and national hero. All of the crew members were Polish. The captain, Zygmunt Pawlaczyk, was 59 years old, with 19,745 flight hours' experience (5,542 on Ilyushin Il-62s), and a captain of the type from 11 May 1978. The first officer, Leopold