A long time ago I saw this thing on TV, I'm not sure if it was a show, mini series or movie, and I want to find it so I can watch it again.
Basically the premise in it, was that this guy was going back in time to nazi Germany, and helping someone, a friend or something, and he goes back and forth from germany to present day. Well a number of times when he went back in time to Germany, he was carrying some strange things with him, one of them happened to be a little high-pitched frequency gadget that made people around have to hold their ears, something similar to a one of those high pitched whistles that some people carry when they are traveling alone at night.
He went back again to Germany, and it was after some time had passed, well the Germans had found the high-pitched sound device, and improved on it, and made a sonic weapon that would destroy people with the noise it made (don't ask me how, it was long ago when I was I kid I saw this).
And I believe one time when they went back to Germany this guy took a Helicopter, reminded me of that show Airwolf, but I think this is a different show.
Anyways, based on this loose amount of info, I hope someone can find this show/movie/mini-series, it was really cool.