The rating on San Francisco Airport Commission, Calif.'s bonds reflects the following strengths: * Greater certainty associated with completion of Near Term Master Plan (NTMP) project budgets, * Demonstrated and expected solid economic underpinnings and positive traffic trends that slowed in fiscal 1998, and * Strong financial performance and debt service coverage. Offsetting credit risks include: * A large and ambitious debt-financed capital program totaling $2.8 billion that will result in higher costs and a substantially leveraged facility when combined with future anticipated projects, and * Continued market share growth of United Airlines Inc. and its code-sharing affiliates, which represent a concentrated 56% of total enplaned passengers in 1998. The bonds are expected to receive a 'AAA' rating based on