CHICAGO--(BUSINESS WIRE)--Fitch Ratings has affirmed the ratings for Burlington, VT's (BTV) approximately $42.7 million of outstanding airport revenue bonds at 'BBB-'. The Rating Outlook is Stable. KEY RATING DRIVERS The 'BBB-' rating reflects a volatile enplanement base serving a small regional market at BTV combined with limited operating and financial flexibility. BTV has a history of weak cash flow but recent strides have enhanced their financial profile as seen in recent improvement of net