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
Royal Flight (airline) Royal Flight (airline) Joint stock company Royal Flight airlines (), formerly Abakan-Avia (), is a charter airline based in Abakan, Russia. It operates charter services between Russian cities and holiday destinations in Sri Lanka, Egypt, Thailand, Turkey, India, Indonesia, United Arab Emirates, Bulgaria, Macau, Taiwan, Maldives, and Vietnam. Its main bases are Abakan Airport (ABA) and El Obeid Airport, Sudan. The airline was established in 1992 as Abakan-Avia and started operations in 1993. It was established from a former Aeroflot unit, and started domestic cargo flights in 1993 and international flights in 1994. Sobol acquired a 70% share in 1999.