A word that gathers a lot of conditions that an aircraft must meet. An official definition does not exist. However, the aviation and aeronautical regulations states the minimum requirements for which the aircraft is deemed to be airworthy and this is also showed under a Certificate of Airworthiness (CofA).
You may think of the minimum conditions for something to work well, adding that aircraft is quite safe, trustworthy and one of the more efficient transportation system. Therefore, the first condition that comes to mind is that the aircraft has the ability to fly, but with this is not enough since the mission of an aircraft is beyond, and along with the flight qualities the aircraft performs other functions where all the operation needs to work well and safe.
The aircraft, meets the certification basis from the design and construction. In the final phase of the aircraft production, the same has a conformity with the design. The manufacturer and designer follow all the steps as planned. The aircraft has consistency with the drawings, specifications and the data from the tests. All these consistency and conformity is reflected in the TC (Type certificate).
After meeting this condition, the aircraft is airworthy. But that is all? When flying the plane, what about the deterioration, wear, the corrosion, the defective components or parts? Is It airworthy? All depends on how those are presented in the aircraft, that is why the state of contracting (it could be where the aircraft operates) by mean of its aviation authority also monitor the operations, explained in a simple form, and this state issues or approves a Certificate of Airworthiness (CofA). The operator or the owner of the aircraft have the obligation of having the plane in a safe condition to fly and the aviation authority or the competent organization issues the CofA.
For maintaining a CofA valid through aircraft usage time, the plane needs to meet the requirements that the regulations state under the rules, directives and what the manufacturer says according to the design, maintenance instructions. Here comes the aircraft maintenance which is during the entire life of the aircraft and it is called Continuing Airworthiness, so they are the requirements for maintaining the aircraft in an airworthy condition, therefore it is safe to operate.
Having explained the airworthiness meaning, it is simple, but at the same time a complex word where all the systems of the aircraft needs to meet many requirements to be considered safe to fly and be precise to the design. Such a way the competent authority issues the certificate.
rusaviainsider.com//Leonid Faerberg / Transport-Photo.com