A lot of the regulations are set at component level, no?
Dont some even require DOT markings on the component?
I thought NHTSAs minimum safety performance standards were mandatory for lighting, tires/brakes, etc?
In any practical sense youre not developing a vehicle without considering meeting requirements being foundational.
I get the distinction youre trying to make, but you cant compare few thousand unit per year business of airplane sales to consumer automaking. The government would get log jammed. Also reducing NCAP to a shaming tool seems a bit reductive.
Safety standards are mandatory but meeting them is at the word of the automaker, not checked by a government regulatory agency
before going on sale. NHTSA may checks
after a vehicle is on sale, but it does not even check all (100%) of the vehicles sold each year.
Here, in a nutshell, is the difference between a post-market compliance check (for automobiles) and a premarket certification (for aircraft).
For automobiles, a regulatory agency publishes standards that must be met (for components, whole sub-systems, whole vehicle, etc.). The automaker self-certifies that they have met them and puts the vehicle on sale. The regulatory then does checks after the vehicle is already on sale.
For aircraft, a regulatory agency publishes standards that must be met (for components, whole sub-systems, whole aircraft, etc.). The airplane (and component) manufacturers claim to meet them and the regulatory agency checks (and foreign agencies may double check). The regulator (or designated representatives not employed by the regulator but qualified to perform certification checks on behalf of the regulator) does this for all the engineering designs of all components, sub-systems, airplanes. Aircraft are incredibly complicated and complex, and these certification checks take years before an aircraft type is approved for commercial flight; approval for foreign flight may add to the certification time. Aircraft engineering designs do not change every year but only every few years (or decades) and each re-certification takes a lot of time.