The relationship between Boeing and the Federal Aviation Administration, which has set the global standard in aviation safety for decades, will come under unprecedented scrutiny this week after two deadly airline crashes.

Both accidents involved a Boeing jet green-lighted by the U.S. regulator, which relied heavily on safety assessments made by Boeing employees.

In a startling break from the past, other nations and airlines grounded the Boeing 737 Max en masse after the second fatal crash this month while the same model of plane continued to carry tens of thousands of passengers a day in the United States.

This week, Congress joins the investigation into Boeing and the FAA. On Wednesday, the Senate aviation subcommittee will examine how the FAA oversees safety in the commercial aviation industry.

The acting FAA chief is scheduled to testify. So is the Transportation Department’s inspector general, who is conducting a separate probe of the FAA’s decision to approve the Boeing 737 Max aircraft, the type of plane that crashed in Indonesia in October, and then in Ethiopia two weeks ago.

The U.S. House plans to hold its own hearings and The Associated Press has reported that the Justice Department is also investigating.

At the very least, it looks like Boeing and the FAA are going to be under more intense scrutiny for some time.

Here are some questions that lawmakers are almost certain to ask:

CAN FAA EFFECTIVELY REGULATE BOEING?