I found an interesting site while I was looking for airport ringtones.
This site collects various sound data files that can be distributed as creative commons. All data are posted by registered users. You can find many sound data files of an announcement at the airport, in an airplane, etc.
These are links for example.
http://www.freesound.org/samplesViewSingle.php?id=59605
http://www.freesound.org/samplesViewSingle.php?id=36434
You can preview sound by clicking on the playing button which you can find at ‘Waveform & Preview’. If you want to download data, you have to register. Enjoy!