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
Three-letter acronym Three-letter acronym A three-letter acronym (TLA), or three-letter abbreviation, is an abbreviation, specifically an acronym, alphabetism, or initialism, consisting of three letters. These are usually the initial letters of the words of the phrase abbreviated, and are written in capital letters (upper case); three-letter abbreviations such as "etc." and "Mrs." are not three-letter acronyms, but "TLA" is a TLA (an example of an autological abbreviation). Most three-letter abbreviations are "initialisms": all the letters are pronounced as the names of letters, as in "APA" . Some are acronyms pronounced as a word; computed axial tomography, CAT, is almost always pronounced as