Ratings on Boeing Co. are supported by its position as one of two globally dominant producers of commercial aircraft, generally favorable long-term fundamentals for that business, a very strong position in defense and space, relatively low debt use, and anticipated good overall financial performance. Near-term challenges include the need to scale down commercial airplane production rates and adjust the related cost structure to maintain satisfactory profitability and cash flow, given weak demand for jetliners. In Boeing's largest segment--commercial airplanes--intermediate-term business prospects deteriorated significantly, due to the Sept. 11, 2001, terrorist attacks and a soft global economy. In the aftermath of those attacks, reduced air traffic, losses at airlines, grounded aircraft, and passenger security concerns will constrain demand for new planes