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
No. 1586 (Polish Special Duties) Flight especially difficult, lasting up to eleven hours. The flight was disbanded on 7 November 1944 at RAF Brindisi, Italy to resume operations as No. 301 Polish Bomber Squadron. No. 1586 (Polish Special Duties) Flight No. 1586 (Polish Special Duties) Flight was first formed at RAF Derna, in Libya on 4 November 1943, equipped with Handley Page Halifax II special duties aircraft. The origin of 1586 flight was the remnants of 301 (Polish) Squadron after disbandment on 31 March 1943 by the Polish HQ due to lack of staff and trained crews. Volunteer crews and aircraft formed C Flight of 138