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
Airline codes has been in place for 20 years. The codes issued to date comply with IATA Resolution 762, which provides for only two characters. These codes thus comply with the current airline designator standard, but use only a limited subset of its possible range. There are three types of designator: unique, numeric/alpha and controlled duplicate. IATA airline designators are used to identify an airline for commercial purposes in reservations, timetables, tickets, tariffs, air waybills and in telecommunications. A flight designator is the concatenation of the airline designator, xx(a), and the numeric flight number, n(n)(n)(n), plus an optional one-letter "operational suffix" (a).