A formation of F/A-18 Hornet strike fighters assigned to the U.S. Navy flight demonstration squadron, the Blue Angels, fly over San Diego Harbor while participating in the Parade of Flight, an air show showcasing historic and current Naval aircraft in celebration of the Centennial of Naval Aviation, February 12, 2011. The Navy is observing the Centennial of Naval Aviation with a series of nationwide events celebrating 100 years of heritage, progress and achievement in naval aviation. REUTERS/Mass Communication Specialist 2nd Class Roland A. Franklin/Handout (UNITED STATES – Tags: MILITARY) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS