Airworthiness


In aviation, airworthiness is the measure of an aircraft's suitability for safe flight. Initial airworthiness is demonstrated by a certificate of airworthiness issued by the civil aviation authority in the state in which the aircraft is registered, and continuing airworthiness is achieved by performing the required maintenance actions.
Certification is based on standards applied by civil aviation authorities. Interoperability is served when national benchmarks adopt standards from international civil and military organizations such as International Civil Aviation Organization, European Aviation Safety Agency, NATO and European Defence Agency.
In the U.S., Title 14, Code of Federal Regulations, Subchapter F, Part 91.7 states: "a) No person may operate an aircraft unless it is in an airworthy condition. b) The pilot in command of a civil aircraft is responsible for determining whether that aircraft is in condition for safe flight. The pilot in command shall discontinue the flight when unairworthy mechanical, electrical, or structural conditions occur which compromise the airworthiness."

Jurisdictional heterogeneity

One airworthiness regulation is found in ICAO international standard of Annex 8 to Chicago Convention on International Civil Aviation which defines "airworthy" - in respect of an aircraft, engine, propeller or part there of - as "The status of an aircraft, engine, propeller or part when it conforms to its approved design and is in a condition
for safe operation". The application of airworthiness defines the condition of an aircraft and its suitability for flight, in that it has been designed with engineering rigor, constructed, maintained and is expected to be operated to approved standards and limitations, by competent and approved individuals, who are acting as members of an approved organization and whose work is both certified as correct and accepted on behalf of the state of aircraft registry.
Apart from this organization, there are other ones like Federal Aviation Administration or EASA that establish their own rules. In the case of the FAA, the regulation of airworthiness is found in Title 14 in the collected Code of Federal Regulations. The EASA specifications are found in several regulations: as nº 216/2008, nº 748/2012, nº 2015/640 and nº 1321/2014.

European regulation

In the regulation nº216/2008, common rules in the aviation sector are established and created the European Aviation Safety Agency. Article 5 of this regulation details the first specifications about airworthiness. Article 20 is about airworthy certification.
The main objective of these rules are to establish and to maintain a high and uniform security level at the civil aviation in Europe. For that reason, it lays down different rules according to the airworthiness:
  • The jets will accomplish the essential established requirements in annex I in airworthy section.
  • It will be proved that the products possess a type certificate. Moreover, it is necessary to include modifications certificate of the same jet. This should be included in supplementary type certificate. Both of them may be sold when an applicant proves that their product achieves the regulations' basis.
  • No airplane can be operated without a valid certificate of airworthiness
  • A certificate of airworthiness will be issued when the applicant has demonstrated that the aircraft is conformed to the design of the model approved in its type certificate and that the pertinent documentation, inspections and tests confirm that the aircraft is in a condition for safe use. The certificate of airworthiness shall be valid as long as it is not canceled, or annulled, or is left without effect, provided that the aircraft is kept in accordance with the essential requirements for maintenance of airworthiness.
  • The Commission will ensure, in particular, because the current state of the art and best practices in airworthiness are reflected; keep in mind the experience accumulated in service by aircraft throughout the world, as well as scientific and technical progress; allow immediate response, once the causes of accidents and serious incidents are determined; do not impose requirements on aircraft that are incompatible with the obligations assumed by the Member States by virtue of their belonging of the International Civil Aviation Organization.

    Initial airworthiness

The Regulation No. 748/2012 establishes the dispositions of application on the airworthiness and environmental certification of aircraft and related products, components and equipment, as well as the certification of design and production organizations.
Besides of the technical requirements and common administratives procedures by the airworthiness and environmental certification, the following aspects can be found too in regulation nº 748/2012:
  • The dispatch of type certificates, of restricted type certificates, of supplementary type certificates, as well as the modifications of said certificates.
  • The dispatch of repair design approvals.
  • The demonstration that environmental protection requirements are met.
  • The dispatch of noise level certificates.
  • The identification and certification of products, components and equipment.
  • The certification of the design and production organizations.
  • The dispatch of airworthiness directives.
This regulation contains an annex, Part-21, which specifies the requirements and procedures for the certification of aircraft and related products, components and equipment, and design and production organizations. Apart from this annex, there are also several certification specifications, including CS-25, for large aircraft, and CS-23, for medium and small aircraft.
In application, airworthiness standards include a probability of loss of aircraft that is designed to be controllable as an overall attribute. Setting a sufficiently robust PLOA factor for the aircraft's ability to safely attain, sustain, and terminate flight protects the souls on board. An aircraft safe enough to carry human life is presumed safe to fly over people on the ground. For "airworthiness regulations serve to protect people onboard the aircraft... the protection of persons and property on the ground another benefit. "
However, for unmanned aircraft, airworthiness must only address the safety of people on the ground and not the aircraft itself. This changes the assessment of risks and hazards, allowing a new approach that accounts for risk and consequence in the setting of airworthiness requirements. For military unmanned aircraft, France developed an unmanned-unique airworthiness concept, later adapted by NATO, that isolates failures catastrophic to human life. The concept later came to be described as the "Cumulative Probability of all Catastrophic Failure Conditions" or. Here, two outcomes are addressed.
First, an airworthiness issue arises from an uncontrolled crash, which is defined as a condition resulting from one or a combination of failure conditions that prevents the flight control system from controlling and maneuvering the aircraft until the impact on the ground AEP-4671 page A-5. To be certified to fly over any population density, an hypothetical uncontrolled crash assumes that human life at the point of impact is lost.
In the second outcome, a forced landing or recovery at a predefined and unpopulated area is defined as a condition resulting from one or a combination of failure conditions that prevents the UAV from landing on its planned main landing site, although the flight control system is still able to control and maneuver the UAV.. While the aircraft may be lost, residual maneuverability directing to an unpopulated point of impact means this alternative is not catastrophic and therefore not an airworthiness factor. Though the aircraft may be lost or considered a hull loss, the flight has been safely terminated.

Additional airworthiness specifications

The Regulation nº 2015/640 establishes additional airworthiness specifications for operations and contains two annexes. The Annex I, Subpart A, is devoted to general provisions on the appropriate authority, temporarily inoperative equipment and demonstration of conformity. Subpart B of the aforementioned annex focuses on large aircraft and contains specifications related to seats, berths, seat belts and harnesses; location, access and markings of emergency exits; emergency interior lighting and operation of emergency lights; interiors hold; flammability of the coatings of cargo compartments; fire protection for toilets; acoustic warning of the landing gear and systems for opening and closing the flight crew compartment door - incapacitation of a crew member. Annex II contains an amendment to Annex III of Regulation No. 965/2012.

Maintaining airworthiness

The Regulation No. 1321/2014 controls the continuing of the airworthiness of aircraft and aeronautical products, components and equipment and the approval of the organizations and staff who involve in these tasks. It contains 7 annexes, although Annex V has been repealed.
Annex I ; Section A, "establishes the measures that must be taken to ensure the continuing of airworthiness, including maintenance. Moreover, it specifies the conditions that must be achieved by the people or organizations involved in the management of airworthiness maintenance." Section B "establishes the administrative procedures to be followed by the competent authority for the application and enforcement of Section A of Part M."
The Annex II ; Section A, "establishes the requirements which an organization must obey to be able to award or maintain a continuing approval of the elements and aircraft." The Section B "establishes the administrative procedures that must be followed by the competent authority to execute its tasks and responsibilities in connection with the concession, modification, suspension or revocation of approvals of maintenance organizations Part 145."
The Annex III ; Section A, "define the aircraft continuing license and set the requirements for its application, dispatch and continuity of its validity." The Section B "establishes the procedures, requirements, administrative requirements, measurement and control of compliance with Section A of Part 66."
The Annex IV ; Section A, "establishes the requirements that must be fulfilled by the organizations that request authorization to carry out training courses and specific examinations in Part 66." Section B "establishes the administrative requirements that must be followed by the competent authorities for the application of section A of this part."
The Annex V bis ; Section A, in accordance with the fundamental requirements set out in Annex IV of the Regulations No. 216/2008. The conditions to be had by the people and organizations responsible for managing the maintenance of airworthiness and the maintenance of the aircraft in question are also specified." The Section B "establishes the administrative procedures that must be followed by the competent authorities in charge of the application and compliance of Section A of Part T."
The Annex VI contains a table of correspondence between Regulation No. 2042/2003 and these regulations.