ARLINGTON, Va. — Boeing announced plans to acquire Spirit AeroSystems for $4.7 billion in an all-stock transaction for the manufacturing firm, which already was part of the aerospace company’s manufacturing chain. Boeing, located in Arlington, Va., announced the purchase in a statement late Sunday. [time-brightcove not-tgx=”true”] The acquisition’s equity value of $4.7 billion is $37.25 per share, while the total value of the deal is around $8.3 billion, which includes Spirit’s last reported net debt, the aerospace company said. Boeing common stock will be exchanged for Spirit shares according to a variable formula that depends on a weighted average of the share price over a 15-trading-day period ending on the second day before the deal closes, Boeing said. Spirit, located in Wichita, Kans., manufactures key parts for Boeing aircraft.