Airworthiness Directive

An airworthiness directive ( AD ), International airworthiness directive (AD), contains a list of actions to be taken if it is determined after approval of an aviation unit to be defective, and thus the airworthiness is limited. The actions set out to restore the airworthiness and may include inspections, repairs etc.. Only when the prescribed actions have been carried out in accordance with regulations, the air carrier concerned unit must be put back into operation. The airworthiness directive is usually written by the certifying body and announced in the Notices to Airmen or in the brochure by the officer. They will also be published on the websites of the aviation authorities.

Situation in Germany

In Germany LTAs are from the Federal Aviation Authority in the Notices to Airmen, or in the information document of the Commissioner published (§ 14 LuftBO ).

Situation in other countries

In the United States, the Federal Aviation Administration is responsible for the publication of airworthiness directives and in Canada, the Ministry of Transportation, Transport Canada.