NEW YORK (Standard&Poor's) Sept. 21, 2001-- Standard&Poor's today placed its ratings on 13 commercial aerospace companies and their related entities on CreditWatch with negative implications (see list below). At the same time, outlooks were revised to stable from positive on two other commercial aerospace firms and outlooks were revised to negative from stable on eight additional issuers in this sector. The Sept. 11, 2001, terrorist attacks against the U.S. have had a severe impact on commercial aviation. The domestic airline industry has been hit particularly hard and most carriers have announced they plan to reduce capacity by about 20%. As a consequence, companies serving the airline sector—including airplane manufacturers (such as Boeing Co., Bombardier Inc., and