...Strong Competitive Positions: The Boeing Company's (BA) ratings reflect its competitive positions in the commercial aerospace and defense sectors, high barriers to entry in its key businesses and large backlog ($480 billion). The company's portfolio is less balanced than it once was, as commercial growth has reduced defense revenues to less than one-third of revenues. Key concerns include margin levels, substantial charges, and the pension deficit. Healthy Commercial Aircraft Outlook: The commercial aerospace market is currently healthy, and BA's commercial backlog at the end of May 2017 (5,646 aircraft) reflects this strength. Several transitioning programs drove BA's 2016 deliveries down modestly to 748 aircraft. Fitch expects deliveries will rebound to approximately 770 aircraft in 2017 and 820 aircraft in 2018. Defense Outlook Improving: U.S. defense investment spending increased in 2016 after a three-year trough and Fitch expects continued solid spending levels in 2017 and beyond....