An Airworthiness Directive (commonly abbreviated as AD) is a notification to owners and operators of certified aircraft that a known safety deficiency with a particular model of aircraft, engine, avionics or other system exists and must be corrected.[1][2]
If a certified aircraft has outstanding airworthiness directives that have not been complied with, the aircraft is not considered airworthy.[1][2]
Contents |
Purpose
ADs usually result from service difficulty reporting by operators or from the results of aircraft accident investigations. They are issued either by the national civil aviation authority of the country of aircraft manufacture or of aircraft registration. When ADs are issued by the country of registration they are almost always coordinated with the civil aviation authority of the country of manufacture to ensure that conflicting ADs are not issued.
In detail, the purpose an AD is to notify aircraft owners:
- that the aircraft may have an unsafe condition, or[3]
- that the aircraft may not be in conformity with its basis of certification or of other conditions that affect the aircraft's airworthiness, or[3]
- that there are mandatory actions that must be carried out to ensure continued safe operation, or[3]
- that, in some urgent cases, the aircraft must not be flown until a corrective action plan is designed and carried out.[3]
ADs are mandatory in most jurisdictions and often contain dates or aircraft flying hours by which compliance must be completed.
ADs may be divided into two categories:[citation needed]
- Those of an emergency nature requiring immediate compliance prior to further flight, and
- Those of a less urgent nature requiring compliance within a specified period of time.
Issuance
ADs are issued by most civil aviation regulatory authorities, including:
- Civil Aviation Safety Authority (Australia)
- European Aviation Safety Agency
- Federal Aviation Administration (USA)
- Transport Canada[1]
National procedures
United States
The American FAA issues ADs by three different processes:[4]
- Standard AD process: Notice of Proposed Rulemaking (NPRM), followed by a Final Rule
- Final Rule and Request for Comments
- Emergency ADs - issued without time for comment. This is only used issued "when an unsafe condition exists that requires immediate action by an owner/operator...to rapidly correct an urgent safety of flight situation."[4]
See also
References
- ^ a b c Transport Canada (October 2008). "Aeronautical Information Manual, LRA - 2.0 Aircraft Airworthiness, Airworthiness Directives". http://www.tc.gc.ca/CivilAviation/publications/tp14371/LRA/2-1.htm#2-7. Retrieved 2008-11-03.
- ^ a b Transport Canada (January 2008). "Canadian Aviation Regulation 605.84 Aircraft Maintenance - General". http://www.tc.gc.ca/CivilAviation/Regserv/Affairs/cars/PART6/605.htm#605_84. Retrieved 2008-11-03.
- ^ a b c d Transport Canada (January 2008). "Canadian Aviation Regulation Standard 593.02 Airwothiness Directives". http://www.tc.gc.ca/CivilAviation/Regserv/Affairs/cars/Part5/Standards/593s.htm#593s_02. Retrieved 2008-11-03.
- ^ a b Federal Aviation Administration (October 2009). "Types of Airworthiness Directives". http://www.faa.gov/aircraft/air_cert/continued_operation/ad/type_pub/. Retrieved 2009-10-04.
External links
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
