The head of Boeing's commercial airplane division, which includes the company's North Charleston campus, told employees in a webcast that the aerospace giant will trim its workforce, starting with executives and managers. Ray Conner's announcement was part of a wider discussion focusing on the division's finances and competitive landscape. It was not clear when job cuts would begin. A spokesman said the company also plans to use voluntary layoffs and attrition to reach its employment goals. Boeing Co. employs about 7,500 workers and contractors in the Charleston region.