A revolt by U.S. airline bosses helped topple Boeing's top leadership including CEO Dave Calhoun this week, capping weeks of pressure after the freakish Jan. 5 blowout of a door plug on an Alaska Airlines 737 MAX 9 passenger jet, people familiar with the discussions said. With the company's major U.S. customers agitating for a boardroom meeting without Calhoun, Boeing's board pre-empted their demands with a major upheaval. Now, after the shakeup that took out the CEO, chairman and head of Boeing's commercial airplanes business, airlines face prolonged uncertainty over jet supplies and are calling for deeper changes - starting with picking a manufacturing heavyweight as CEO.