Boeing’s largest white-collar union will vote Thursday on whether to accept a revised contract offer that raises guaranteed pay increases for about 17,000 members. The Society of Professional Engineering Employees in Aerospace (SPEEA) is in its first full contract negotiations in 14 years, seeking better wages, work-life protections and other job improvements as Chief Executive Kelly Ortberg manages a new software problem, production hiccups and the years-late 777X program. A rejection could allow a strike as soon as Oct. 7, after current contracts expire the previous day. The walkout would halt Boeing’s certification campaigns for the 737 MAX 10 and 777-9 and disrupt deliveries, both important to the planemaker’s financial recovery. The revised four-year deal would provide an average 32% raise, up from 26.5% under Boeing’s first offer, while union councils for both bargaining units now recommend approval. Some members have switched their support, though others say the proposed increases may not adequately offset future inflation and higher fuel prices.