The CEOs of Alaska Airlines and United Airlines say they are frustrated and angry about ongoing manufacturing problems at Boeing. United’s CEO said Tuesday that his airline will consider alternatives to buying a new version of the Boeing 737 Max. Scott Kirby says Boeing needs “real action” to restore its previous reputation for quality. Alaska Airlines CEO Ben Minicucci says he’s demanding to know how Boeing is going to fix its quality problems. Alaska has 59 Boeing 737 Max 9 jetliners, and United has 79 of the planes. All of them have been grounded for nearly three weeks after a panel blew out of an Alaska Airlines Max 9 in midflight.