Boeing CEO Dave Calhoun will leave his post at the end of the year and the company’s chairman of the board will step down this spring as the aerospace company reels from increased scrutiny from regulators in the wake of near-disasters including a door blowout in mid-flight earlier this year. The company’s chairman‚ Larry Kellner‚ is stepping down from the board of directors in May while Stan Deal‚ president and CEO of Boeing Commercial Airplanes‚ is resigning effective immediately‚...