Public Utilities Code § 22904

Annually, after receiving the estimates, the board of supervisors shall levy a tax sufficient for the payment of the principal and interest on the bonded indebtedness, designated as the “____ airport bond tax,” and a tax sufficient for the payment of all other expenses of, and claims against, the district, designated as the “____ airport district tax.”

The bond tax shall be levied annually until the bonded indebtedness is fully paid. The district tax shall be levied annually until all other expenses of and claims against the district are fully paid.