They weigh 80-85lbs and travel at speeds of around 50mph. The impact would be quite serious, if they crash at speed but even falling on a car or a human would

They weigh 80-85lbs and travel at speeds of around 50mph. The impact would be quite serious, if they crash at speed but even falling on a car or a human would be quite serious, possibly deadly, even if the propellers don't spin.