Boeing announced plans to acquire key supplier Spirit AeroSystems for $4.7 billion, a move that it says will improve plane quality and safety amid increasing scrutiny by Congress, airlines and the Department of Justice.

Boeing previously owned Spirit, and the purchase would reverse a longtime Boeing strategy of outsourcing key work on its passenger planes. That approach has been criticized as problems at Spirit disrupted production and delivery of popular Boeing jetliners including 737s and 787s.

“We believe this deal is in the best interest of the flying public, our airline customers, the employees of Spirit and Boeing, our shareholders and the country more broadly,” Boeing President and CEO Dave Calhoun said in a statement late Sunday.