What ever number you want to use...4, 5, 6, 7 years of development...and the sounds that are in the game or have been left out all together...wind with open cockpit, landing gear, lawn mower, etc, etc, it just boggles the mind. IMHO most everything in the current game is a place holder but the good news is with the dev team creating all new sounds and guys like Jafa and Big Pickle doing their thing, maybe this porked part of the game will be fixed in a few weeks/months. Hopefully not years