Approval of the deal with 38 percent raises over four years is a key step toward recovery after Boeing suffered billions in losses from the work stoppages and safety problems.

Striking machinists accepted a new contract raising wages by 39 percent, but enduring bitterness will complicate Boeing’s efforts to rebuild its battered corporate culture and flawed production process.

The work stoppage by 33,000 factory workers at the struggling aerospace giant comes to an end after more than seven weeks.