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.
Sixty-four percent of those who voted cast a ballot to reject the proposed deal, which Boeing had hoped would be enough to end a nearly six-week walkout.
Negotiations between Boeing and 33,000 striking machinists have broken down as the walkout that has put the company’s financial future at risk enters its fourth week.