World record of speed for career hydroplanes. The Macchi M.C. 7

The Macchi M.C. 72 was an experimental seaplane designed and built by the Italian aircraft company Macchi Aeronautica. The M.C. 72 held the world speed record for all aircraft for five years. In 1933 and 1934, it set a world record for speed over water which still stands to this day.

Design and development

The Macchi M.C. 72 was one of a series of seaplanes developed by Macchi Aeronautica. An earlier model, the M.24 was a twin-engine flying boat armed with machine guns and capable of carrying a torpedo. Later in the 1920s, Macchi focused on speed and on winning the Schneider Trophy. In 1922, the company hired aircraft designer Mario Castoldi to design high-speed aircraft.
In 1926, the company won the trophy with the M.39 which attained a top speed of 396 km/h (246 mph). Further planes (the M.52, M.52R, and the M.67) were designed and built but victory in the Schneider races kept eluding the Italians. Castoldi then designed the ultimate racing seaplane, the M.C. 72, a single seater aircraft with two floats.
The design of the Macchi M.C. 72 was unique with a fuselage partly metal to the cockpit and wood monocoque bolted to the front tubular portion by four bolts.  The streamlined nose contours enclosed an oil tank with its outside wall exposed to the airstream. The wing was all metal with flat tubular water radiators smoothly faired into the wings. The twin pontoons had three smoothly-faired radiators on the outer surfaces, the forward radiator for water and the centre and rear radiators for oil cooling  The float struts also featured water radiators and another radiator was fitted during hot conditions under the fuselage running from cockpit to tail.  
It was built in 1931 with the idea of competing for what turned out to be the final Schneider Trophy race, but due to engine problems, the plane was unable to compete.

Warrant Officer Francesco Agello, test pilot of the Macchi M.C. 72

Instead of halting development, Macchi continued work on the M.C. 72. Benito Mussolini personally took an interest  in seeing development of the M.C. 72 continue and directed state funds to the company.

Operational history

For two years, the plane suffered from many mechanical defects, as well as the loss of two test pilots who died trying to coax world class speed out of the M.C. 72 (first Monti and then Bellini). The final design of M.C. 72 used a double, contra-rotating propellers powered by a modified FIAT AS-6 engine V24 engine) generating some 1,900-2,300 kW (2,500-3,100 hp) (thanks to supercharging).
After 35 flights, the engines were overhauled in preparation for a record attempt.  The aircraft finally lived up to expectations when it set a new world speed record (over water) on 10 April 1933, with a speed of 682 km/h (424 mph). It was piloted by Warrant Officer Francesco Agello (the last qualified test pilot). Not satisfied, development continued as the aircraft's designers thought they could break 700 km/h (430 mph) with the M.C. 72. This feat was in fact achieved on 23 October 1934, when Agello piloted the plane for an average speed of 709 km/h (440 mph) over three passes. This record remains (as of 2008) the fastest speed ever attained by a piston-engine seaplane. After this success, the M.C.72 was never flown again.

Speed record

The M.C. 72 held the world speed record for all aircraft for five years. For comparison, the record holder for a land-based aircraft was held (for a time) by the Hughes H-1 Racer with a top speed of only 566 km/h (352 mph). Then in 1939, two German racing aircraft passed the M.C. 72. The first was a Heinkel He 100 which reached the speed of 746 km/h (463 mph). The second racer was a Messerschmitt Me 209 which set the new world speed record of 756 km/h (469 mph) in August – just days before the start of World War II. The current world speed record for a piston-engine aircraft is 850 km/h (530 mph) set by a heavily modified American F8F Bearcat named Rare Bear in 1989. However, the M.C. 72 record still stands today as the world's fastest propeller-driven seaplane.
One M.C. 72 is a surviving airframe, and is on display at the Italian Air Force Museum, near Rome.

Popular culture

• The Miyazaki film Porco Rosso, while clearly not historical, seems inspired by Italian seaplanes and pilots of this period.

Specifications (M.C.72)

Data from Flying-boats and Seaplanes since 1910

General characteristics

• Crew: 1 pilot
• Length: 8.32 m (27 ft 3.5 in)
• Wingspan: 9.48 m (31 ft 1.25 in)
• Height: 3.30 m (10.83 ft)
• Wing area: 15 m² (151.46 ft²)
• Empty weight: 2,505 kg (5,512 lb)
• Loaded weight: 2,907 kg (6,409 lb)
• Max takeoff weight: 3,031 kg (6,669 lb)
• Powerplant: 1× Fiat AS-6 Liquid-cooled V24 engine, 2,126 kW (2,850 hp)

Performance

• Maximum speed: 709.209 km/h (382.9 kn, 440.681 mph) (world speed record)