Any time you take a vintage plane up, there is always the risk of destroying it. I don't know how many B-17's are still around, but the loss of even one is catostrophic.
Had a 17 circling the valley this past memorial day. The sound of those P&W radials had most of the menfolk on the street out in the yards and craning their necks. As it flew off into the distance I visualized it as an Me-109 pilot might have, and pondered all those .50's pointed my way.
I almost flew in a B17. I was 4 or 5 (1952 or thereabouts) and there was an airshow at Maxwell AFB in Alabama. I got separated from the parents in a B17 on exhibit and had crawled back to the tail gunners compartment when the B17 fired up to depart for a flight demo. It was taxing for the active when someone came back to the compartment and found me. The parents had no idea I was on the plane and were getting frantic when it returned and dumped me.
I got to meet a WW-II B-17 pilot several years ago. While at an appointment with my orthopaedic surgeon in Asheville NC I got acquainted with Robert Morgan, Capt. US Army Air Corp, pilot of the Memphis Belle. My Doctor took me back to a room where we got to talk for about 30 minutes. Robert Morgan retired a Brig. General. He passed away a couple years ago. Needless to say I was thrilled.