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 special transport bombers. On 4 November 1943, Flight became No. 1586 (Polish Special Duties) Flight at RAF Derna Libya. It was still named locally by their ex 301 crews and Polish authorities as No. 301 Squadron Land of Pomerania. On 22 December 1943, the Polish flight was transferred to Campo Cassale near Brindisi, Italy, from where it flew above the occupied Europe with special duties. Missions flown by the flight included partisan supply drops and agent insertion. A special effort was undertaken to supply Polish insurgents after an outbreak of Warsaw Uprising in August 1944. Flights to central Poland were