Macchi M.C.72

The Macchi M.C. 72 is an experimental floatplane 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 world speed records for piston engine-powered seaplanes; the latter still stands.

Design and development
The Macchi M.C. 72 was one of a series of seaplanes developed by Macchi Aeronautica. 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. Further aircraft, 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 M.C. 72, a single-seater aircraft with two floats powered by a modified FIAT AS.6 supercharged V24 engine, generating around 1,900-2,300 kW (2,500-3,100 hp), driving contra-rotating propellers.

The forward part of the M.C. 72's fuselage is constructed of metal; aft of the cockpit it is of wood, with a wood skin over a structure of bulkheads and longerons attached to the front section with four bolts. The nose enclosed an oil tank with its outside wall exposed to the airstream. The wing was all metal, with flat tubular water radiators faired into the wings. The twin floats had three radiators on the outer surfaces, the forward radiator for water and the centre and rear radiators for oil cooling. The float struts also had water radiators and another radiator was fitted during hot conditions under the fuselage running from cockpit to tail.

The M.C. 72 was built in 1931 for what turned out to be the final Schneider Trophy race, but due to engine problems was unable to compete.

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 M.C. 72 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). 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. 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 surpass 700 km/h with the M.C. 72. This was achieved on 23 October 1934, when Agello piloted the M.C. 72 at an average speed of 440.681 mph over three passes. This record remains (as of 2019) the highest speed ever attained by a piston-engined 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. Then, in 1939, two German racing aircraft surpassed the M.C. 72. The first was a Heinkel prototype fighter which reached the speed of 746 km/h. The second was the Messerschmitt Me 209, built by Messerschmitt solely for the purpose of setting a new world speed record, which it achieved with a speed of 756 km/h on April 26 – less than 5 months before the start of World War II. The current world speed record for a piston-engined aircraft is 531.53 mph set by a modified P-51 Mustang named Voodoo over three km in 2017. However, the M.C. 72 record still stands as the world's fastest propeller-driven seaplane.

Surviving aircraft
One M.C. 72, the aircraft that took the world record, survives. It is on display at the Italian Air Force Museum, near Rome.