Agello became famous when he succeeded in piloting the Macchi MC 72 seaplane to a new speed record (over water) on 10 April 1933. He attained an average speed of 683 km/h (424 mph). More than a year later he flew the M.C. 72 to a new speed record of more than 700 km/h (709 km/h or 440 mph) on 23 October 1934. Both records, while obtained in a seaplane, also were and currently are, absolute flight airspeed record. No one has ever flown a piston-engine seaplane faster than him.