California Certifications Of Attendance For Aircraft Of Historical Significance are documents that are issued by the California Department of Parks and Recreation's Division of Aviation to mark the attendance of an aircraft that is of historical significance. This document recognizes the aircraft for its unique characteristics, and serves as official proof of its attendance at an event or airshow. The certification includes the aircraft's registration number, make and model, and the event or airshow it attended. There are two types of California Certifications Of Attendance For Aircraft Of Historical Significance: Type 1 and Type 2. Type 1 is issued for aircraft of historical significance that have been in service for at least 20 years, while Type 2 is issued for aircraft of historical significance that have been in service for at least 10 years. Both types of certifications are valid for a period of one year.