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
Letter of Reconciliation of the Polish Bishops to the German Bishops 1000 years of the baptism of Poland. Most German linguists were forced to sign a letter of protest; those who refused were fired from their universities. In addition, the authorities twice refused permission for a planned visit of Pope Paul VI to Poland in 1966. The following year the Polish United Workers' Party planned to limit the number of religious schools, which was also seen as a penalty for the Letter of Reconciliation. The anti-church campaign lasted until Gomułka's downfall in 1970. Letter of Reconciliation of the Polish Bishops to the German Bishops The Pastoral Letter of the Polish Bishops