G
You are much more qualified than me in crash worthiness
In front of a single engine piston is a bloody great piece of engine held to the airframe by a few tiny tubes and not a lot between that and you.
IE not built like a modern car with deformable structures and power units designed to drop down below the passenger compartment in the event of a head on! Little has changed in airframe design in 60 years.
In fact aircraft are very poorly designed for engineer access or crashes!
The killer is not being restrained by belts other than in light collisions but the fact that a massive piece of engine is likely to join you in the cockpit?? That big block of metal is not human friendly
In which case maybe the belt may be a hinderence
In that way twins are much safer as the power units are on the wings?
We consider the wearing of seat belts as we do with a car! In aircraft the benefits of containing you in a protective Cell as in a modern car are not there and as such the benefits of wearing a seat belt questionable
Pace