Cal. Rev. & Tax. Code § 5366

Owners, as well as operators, of private and public airports shall, within 15 days following the lien date of each year, provide the assessor of the county in which the airport is situated with a statement containing a list of names and addresses of the owners, and the make, model, and aircraft registration number, of all aircraft which were using the airport as a base. The assessors of each county shall, not later than the deadline to submit the required statistical statement pursuant to Section 407, provide the California Department of Transportation, Division of Aeronautics with a statement containing a list of names, addresses of owners, make, model, aircraft registration number, and assessed value of all aircraft which were using airports in the county as a base.