Boeing Co is facing growing pressure in Washington as U.S. lawmakers called for executives to testify about two crashed 737 MAX jets while the world’s biggest planemaker worked on returning the grounded fleet to the skies.

The Senate hearing, at an unspecified date, would be the first time that a U.S. congressional committee has called Boeing executives to appear for questioning about 737 MAX passenger plane crashes in October in Indonesia and March 10 in Ethiopia.

On March 27, the same panel, the Senate Commerce subcommittee on aviation and space, also will question U.S. Federal Aviation Administration (FAA) officials. They will likely be asked why the regulator agreed to certify the MAX planes in March 2017 without requiring extensive additional training.

Meanwhile, the FAA on Wednesday sent a notification to global aviation authorities saying the installation of Boeing’s new automatic flight software in the grounded jets and related training was a priority for the agency.

Boeing was sued on Wednesday in federal court in Chicago by the estate of one of the Lion Air crash victims in which the plaintiffs referred to the Ethiopian crash to support a wrongful death claim against the company. A Boeing spokesman said the company does not respond to, or comment on, questions concerning legal matters.

Also on Wednesday, the Seattle Times reported the Federal Bureau of Investigation was joining the investigation into the MAX’s certification. An FBI spokeswoman in Seattle would neither confirm nor deny that it was a part of any investigation.

Criminal prosecutors at the U.S. Justice Department, who are also investigating the FAA’s oversight of Boeing, have issued multiple subpoenas to Boeing in an effort to find out more about how the MAX was certified and marketed, CNN reported late on Wednesday, citing sources briefed on the matter.

Meanwhile, the Pentagon Inspector General said it would investigate a complaint that Acting U.S. Secretary of Defense Patrick Shanahan, a former Boeing executive, violated ethical rules by allegedly promoting Boeing while in office.

REUTERS