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
Darwin Airline airlines: As of September 2017, the Darwin Airline fleet included the following aircraft: Darwin Airline Darwin Airline SA was a Swiss regional airline with its head office in Bioggio, Lugano flying under the brand name Adria Airways Switzerland. It operated scheduled domestic and international services in some western European countries. It used the brand name Etihad Regional from January 2014 to July 2017, when Etihad Airways sold its 33% stake to the owner of Adria Airways. It previously also operated flights on behalf of Alitalia. Its bases were Geneva Airport and Lugano Airport. In November 2017, the Swiss authories suspended