V shape formation. Slow motion and altitude.Down town Miami. Partially cloudy. Very quiet night. Observation made from 5 floor. Bay view balcony outdoors.Direction of the formation NE to SW. Formation was dismissed as any commercial or private airplane/s due to not an authorized or regular route.Estimated altitude 4 to 6,000 ft. Estimated speed 2 to 300 mph.Size of complete formation size of a Boeing 777. NO sound or any noise.Speed combined with size and without noise take away possibility of 777. Observer a Commercial Airplane enthusiast that can determine manufacturer, model and type of engine from its position at any given day. Location of observation localized on busy in-out Miami Int. Airport.The object described movement NE - SW does not comply with MIA landing or take off routes that are W-E or E-W or NE-SW or vice versa.Object/s move from above Miami Port Bridge to over Brickell Ave. Area.Formation brake out over (on Zenith) observer position making a spiral formation braking while dimming down its lights and finally dissolving.