I don't really get what the issue with Airworthiness is..... No aviator gives 2 hoots about airworthiness.... I nor any of my oppos ever think as we are strapping in... "I wonder who is responsible for the airworthiness of this aircraft"....
I don't know who is respnsible and to be honest I don't care.... as long as the aircraft is S and has loads of fuel then lets get airborne.