Airworthy but Unsafe... Certified but Not Airworthy....

The above statements may be true !

Airworthy but Unsafe ....         

        Airworthiness is associated with design evaluation of a product. With the advancement and introduction of new technologies, it is also required that knowledge base of airworthiness evaluation techniques be also developed. 

         

         Foe example, composites as a new technology offers many technological advantages. However, the manufacturing and quality assurance aspects of composite material components, material characterisation etc. are yet not fully understood. One method to overcome this difficulty is to use higher factor of safety; however, this defeats the basic purpose of introduction of new technology. Thus, it may be appreciated that the level of flight safety available at any stage depends on the knowledge base of the airworthiness evaluation. The airworthiness evaluation depends on the technology maturity level (as documented). As technology matures, the documented knowledge will guide to develop means for competent (appropriate) design evaluations. If airworthiness evaluations are inadequate due to improper knowledge on the subject, the aircraft declared airworthy may be unsafe. 

Certified but Not Airworthy ...

          Every aircraft designed and developed is typed certified based on the various design evaluations carried out as well as the type test carried out on the prototype aircraft. The complete type design is recorded in type record. The series manufacture is required to be carried out as per the type design. This calls for series manufacture of the aircraft is to be carried out as per type design. Further, all maintenance activities are to be carried out as per approved programme by approved personnel using appropriate tools and equipment. If this is not done, though the aircraft is certified,, the aircraft may not be safe to fly. Thus the certified aircraft may not be airworthy.