A government watchdog said Friday that federal safety regulators routinely fail to ensure that American Airlines gets to the cause of maintenance shortcomings when they are discovered.

The report raised questions about the FAA’s policy of relying on airline “safety management systems” to find and fix issues before they become hazards.

In one case, American flew a plane with a broken emergency-evacuation slide for nearly three years before telling the FAA.

In another, no risk assessment was done for a plane that had missing engine bushings and improperly installed struts holding the engines in place. The plane made 1,002 flights “in an unairworthy condition,” according to the report.

An FAA spokeswoman said the agency “agrees with many of the recommendations in the report and is taking steps to address them.”

American said it is proud of its safety record and stays in constant touch with regulators including the FAA and welcomes their feedback.