Aircraft assembly workers have walked off the job at Boeing factories near Seattle and elsewhere after union members voted overwhelmingly to reject a tentative contract that would have increased wages by 25% over four years. The strike started at 12:01 a.m. PDT Friday, less than three hours after the local branch of the International Association of Machinists and Aerospace Workers announced 96% of voting workers rejected the proposed contract and 96% approved the work stoppage. The labor action involves 33,000 Boeing machinists, most of them in Washington state. It's expected to shut down production of Boeing’s best-selling airline planes but not affect commercial flights.