From the discussion under the article published by Dziennik.pl here: http://news.journal.pl/events/articles/332959, did-Russians-spoil-in-Smolensk-hel-yes-suspect-mecenas-rogalski.html Comment ~serena: First a fewer  details about aircraft flight. The wing bearing force (for subsonic speeds) is dependent on 4  factors; the wings surface, the angle of the wing approach comparative  to the flight line, the plane velocity  and the most crucial  detail- density of the centre. Consider a situation in which a plane flying at a certain velocity  will enter [...]