ARLINGTON, Va. (AP) — Boeing has announced plans to acquire key supplier Spirit AeroSystems for $4.7 billion. It says the move will improve plane quality and safety. 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. Concerns about safety came to a head after the January blowout of a panel on an Alaska Airlines 737 Max 9 at 16,000 feet (4,876 meters) over Oregon.