There isn't a single thing with 0% risk, that is a stupid standard to have for anything in life from a risk management perspective. If the risk to something is less than the inherent risk of walking down stairs or driving to work then avoiding it just because isn't being smart, it's being ignorant. It doesn't take one bad mechanical failure, there are redundancies. Potential failures are calculated, studies and mitigated. In the early days of airplanes and low level flying it was very risky and there were many accidents; we have learned from them and applied the lessons. No, the risk isn't 0, but it is well within the tolerance of risks that you take every day.