US Navy "Blue Angels" 5-plane 'Line Abreast Loop' maneuver.
Photographed from my roof.
At approximately 3-1/2nautical miles, aircraft #1,2,3,4 and 5 transition to a Line Abreast formation. Approaching Center Point, they complete a loop. Egressing crowd left, aircraft #1-4 shift back to Diamond and detach #5.