You would classify it as a perfect example of a guardian angel or a fluke of luck. If ever there was a person that Murphy's Law applied to, it is I. I will never fall from a plane and survive, but somewhere, at some time, someone has done exactly that.
There have been historical examples of skydivers who have survived the great plunge without a proper parachute. It would be amazing if someone could create technology that would make this more possible. I do think anyone who would knowingly test this theory is likely crazy, but to each their own.
We've all heard about someone lifting a vehicle that was on top of someone or pulling someone from a burning fire, therefore it is absolutely plausible for someone to survive falling from an airplane. Recently we've even heard of people surviving flying across the country while being stuck in the baggage compartment of an airplane or in the wheel of an airplane. While it might not seem logical to our mind, the human spirit and a higher power can perform miracles beyond anything seemingly impossible. In my opinion, Indestructible Alkemade falling anywhere near 18,000 feet from an airplane, and surviving, fits into the miracle category.
This was an amazing story of survival and proof that anything is possible. Falling 18,000 feet, with no parachute, and living to tell about it. Alkemade is not the only one to survive such a fall. There are stories of others who have survived similar situations. So yes, it is possible to survive a fall from an airplane.