U.S. planemaker Boeing faces a "long road" to address safety issues, the head of the Federal Aviation Administration said on Thursday as it prepares to receive the company's plan to address concerns. In late February, FAA Administrator Mike Whitaker gave Boeing 90 days to develop a comprehensive plan to address "systemic quality-control issues" and barred it from expanding 737 MAX production. Boeing has faced mounting questions after a door panel detached during a Jan. 5 flight on a new...