If the prop is windmilling at impact, it will be stopped by the impact more or less at contact time and bend mostly flat. If a prop is under power at impact, it will continue trying to turn well into the impact sequence, giving it more of an S-bend. This can be used to gauge whether or not the engine was running, and what power it was producing if it was running.

Check this link - NTSB preliminary report. There is also a link to the radar plot which is very instructive.http://ntsb.gov:80/Pressrel/2006/061103.htm NeilYPAD