This is a replacement sound file for the fsx 747-400 or whatever plane you fancy just copy or unzipe into C:/ or whatever your harddrive is/ programme files/ microsoft games/ microsoft flight simulator x/simobjects/airplanes and then whatever file you want to change, it is better working with the 747-400, I fly 747-400 and it is the most realistic I can put together. Download and seed my other torrents I have Easyjet missions, aer lingus missions and united airlines missions for upload and I should finally have the british airways fsx mission for download within the next couple of days so keep a look out. I if any probs leave me a comment and i will reply asap.