Many years ago, the NTSB ran umpteen accident cases through a computer, and told it to find any common thread.
One item that it did come up with was that there was somebody in the cockpit whistling in the last 30 minutes prior to the accident.
Soooo - DON'T WHISTLE WHILE YOU ARE IN FLIGHT. It's dangerous.
Or, if you do, just be very careful for the next 30 minutes. Simple.
