Washington (dpa) - The head of the US aviation authority, FAA, Steve Dickson, has heard violent allegations from Congressmen after the devastating crashes of two Boeing jets.

The agency tried to deliberately hinder the investigation into the accident, criticized Republican Party leader Roger Wicker at a Senate hearing in Washington on Wednesday (local time). "Mr. Dickson, I blame you for this," said the Mississippi State Senator and chair of the Commerce, Science and Transport Committee.

Director Dickson admitted mistakes, but firmly rejected the accusations of wall tactics in the investigation and a "culture of secrecy" at the FAA. Both Boeing and oversight are heavily criticized for the calamities that killed a total of 346 people. Boeing is charged with hastily launching the 737 Max in competition with Airbus and neglecting safety. The FAA is accused of having closed its eyes during certification and letting the manufacturer fool it.

According to FAA boss Dickson, who took office in August 2019 - months after the two Boeing crashes - the agency has already put its regulatory processes to the test in the face of the criticism. The FAA has already started to revise its mechanisms and welcomes political proposals. Dickson emphasized that there were no deadlines for his employees to re-register the 737 Max. Boeing is keen to bring the model, which was banned shortly after the second crash in March 2019, back into operation this summer.

Various investigations have been carried out to determine whether everything went well in the certification of the 737 Max. There is suspicion that the Boeing FAA has been misled and important information has been misappropriated during the approval process. Tricky internals sometimes put so much strain on the relationship between the company and the authority that the tensions were considered a reason for the expulsion of former CEO Dennis Muilenburg in December. Boeing had to justify itself for controversial employee chats, which included the 737 Max: “This aircraft is designed by clowns, who in turn are supervised by monkeys.”