Boeing has received more than six times as many tips from employees versus a year ago following an increased focus on production quality after a door plug dislodged into the sky on a Boeing flight out of Portland, Oregon. Outgoing chief executive Dave Calhoun told the shareholders’ meeting on Friday about the sharp rise in reporting to an internal website for confidential reports. In January a nearly brand new Boeing 737-9 Max operated by Alaska Airlines lost a door plug while climbing after leaving the airport in the north-western state. A high school teacher west of the airport found the pan…