Eight years ago, U.S. regulators substantially increased their dependence on the aircraft industry to help keep flying safe.

The U.S. Federal Aviation Administration(FAA) said it would no longer directly manage routine inspection of design and manufacturing. Instead, it would focus on overseeing a self-policing program executed by the manufacturers themselves through more than 3,000 of their employees assigned to review safety on behalf of the FAA.

These so-called designees had existed for decades, but the FAA had vetted and controlled them. Under the new system, companies chose and managed them, to the point where the FAA even had trouble rejecting those they felt were unsuitable for the job, according to one government watchdog.

As the drama of the overheating lithium-ion batteries on the Boeing 787 Dreamliner unfolds, that relationship is coming under intense scrutiny.

No evidence has surfaced that the designee system is responsible for the battery problem that has prompted regulators to temporarily ban the plane from the skies. The story has raised the question, however, whether the regulator hands over too much power to the industry.

“This is an occupation with a built-in conflict of interest,” said Gordon Mandell, a retired FAA certification engineer.

With Boeing doing about 95 percent of its own inspections, adds Mary Schiavo, former Department of Transportation inspector general, “it’s kind of do-it-yourself.” The situation was not unique to Boeing, she said. “There are places around the world that saw an FAA inspector once, maybe five years ago, and that’s it.”

HOW WERE TESTS VERIFIED?