During training with my instructor, once, we had a real engine failure in a helicopter! It happened very fast, but we made it to the ground safely and landed in a parking lot near Half Moon Bay, next to the ocean!
I learned quite a bit from this experience, including "Luck Is What Happens When Preparation Meets Opportunity." My instructor and I had worked on emergency procedures many times before, and we both executed a well-rehearsed, pre-determined plan as per our memorized checklists. While my instructor did the flying and landed the helicopter safely, I also learned about Aeronautical Decision Making and Crew Resource Management via a real-life adventure!
There was a nut loose from the previous maintenance check in one of the six engine cylinders (human error), one that could not have been caught in the pre-flight inspection. The engine itself was fine, and the cylinder was replaced with a new one.
Flying is still safe. Accidents are rare, but they do happen; never become complacent.
The helicopter in the parking lot shortly after landing
Local police and park rangers show up
Picture of the helicopter at night, next to the ocean
The aircraft was repaired by a mechanic on site, a day after the incident