Hangar Noise

CAR 521 and its predecessor CAR 591 Service Difficulty Reporting

Through Transport Canada’s initiative to harmonize with the Federal Aviation Administration (FAA) and Joint Aviation Authorities (JAA), on 1 December 2009, Canadian Airworthiness Regulation (CAR) 521 came into force and superseded CAR standards 511, 513, 591 and 593.

In order to better inform and familiarize the aviation community, Transport Canada would like to bring attention to the introduction of CAR 521 and specifically highlight a difference from the former CAR 591.

Under the former CAR Standard 591, “Suspected Unapproved Parts” (SUP) were treated as an item within the SDR system. Now under CAR 521 this is no longer the case. SUP are now referenced in Standard 571.13 through an information note. The intent is that these suspected unapproved parts will still be reported using the tools available through the WSDRS program however they have a specific code to identify that they are not service difficulties. This change is also reflected on the SDR Logic Chart.

The purpose of the SDR system is to collect, analyze, record and disseminate data concerning defects, failures and malfunctions which have resulted in, or may potentially, result in a safety hazard to an aircraft or its occupants.

The SDR is still a mandatory report requirement and the purpose of the Web Service Difficulty Reporting System (WSDRS) procedure has not changed. Keeping the core function of the SDR process the same for all users. 

Date modified: