Boeing is posting another loss as the pandemic continues to undercut demand for new planes and the company deals with more problems around its 737 Max jetliner. Boeing Co. said Wednesday it lost $537 million in the first quarter. That’s less than the company lost a year ago but still more than analysts expected. Since the quarter ended, Boeing has suffered a new setback with its 737 Max jetliners, more than 100 of which are now parked again because of issues around electrical grounding of some parts. CEO David Calhoun says 2021 is an “inflection point” for Boeing, with distribution of vaccines against COVID-19 picking up and helping the airline industry.