The Piaggio P.7, also known as the Piaggio-Pegna P.c.7, was an Italian

racing In sport, racing is a competition of speed, in which competitors try to complete a given task in the shortest amount of time. Typically this involves traversing some distance, but it can be any other task involving speed to reach a specific go ...

seaplane A seaplane is a powered fixed-wing aircraft capable of takeoff, taking off and water landing, landing (alighting) on water.Gunston, "The Cambridge Aerospace Dictionary", 2009. Seaplanes are usually divided into two categories based on their tec ...

designed and built by

Piaggio Piaggio & C. SpA (Piaggio ) is an Italian motor vehicle manufacturer, which produces a range of two-wheeled motor vehicles and compact commercial vehicles under seven brands: Piaggio, Vespa, Gilera, Aprilia, Moto Guzzi, Derbi, and Scarabeo. ...

for the 1929

Schneider Trophy The Coupe d'Aviation Maritime Jacques Schneider, also known as the Schneider Trophy, Schneider Prize or (incorrectly) the Schneider Cup is a trophy that was awarded annually (and later, biennially) to the winner of a race for seaplanes and flying ...

race.

Design and development

Seeking to avoid the aerodynamic drag induced by floats in seaplanes of

floatplane A floatplane is a type of seaplane with one or more slender floats mounted under the fuselage to provide buoyancy. By contrast, a flying boat uses its fuselage for buoyancy. Either type of seaplane may also have landing gear suitable for land, ...

design,

Ing Ing, ING or ing may refer to: Art and media * '' ...ing'', a 2003 Korean film * i.n.g, a Taiwanese girl group * The Ing, a race of dark creatures in the 2004 video game '' Metroid Prime 2: Echoes'' * "Ing", the first song on The Roches' 199 ...

Giovanni Pegna Giovanni Pegna (4 January 1888 – 19 May 1961) was an important figure in the development of Italian aviation. He was the head of the construction department of Piaggio and later of the Officine Meccaniche Reggiane, a subdivision of Caproni. ...

of the

company designed a very unusual seaplane to represent Italy in the 1929 Schneider Trophy race. A

cantilever A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cant ...

shoulder-wing

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

, known both as the Piaggio P.7 and the Piaggio-Pegna P.c.7, his design floated up to its

wing A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is exp ...

s on its long, slender, watertight fuselage with the wings resting on the water, and employed twin high-

incidence Incidence may refer to: Economics * Benefit incidence, the availability of a benefit * Expenditure incidence, the effect of government expenditure upon the distribution of private incomes * Fiscal incidence, the economic impact of government taxa ...

hydrofoils to get itself off the water during takeoff runs.Vašiček, Per. ''Aviation History'', September 2002, p. 35. Sources differ on the P.7s engine; it is described both as an

Isotta Fraschini Isotta Fraschini () was an Italian luxury car manufacturer, also producing trucks, as well as engines for marine and aviation use. Founded in Milan, Italy, in 1900 by Cesare Isotta and the brothers Vincenzo, Antonio, and Oreste Fraschini, in 19 ...

Special V6 rated at and as an Isotta Fraschini AS-5 of .Vašiček, p. 35. The engine was connected both to a two-bladed automatic

variable-pitch In marine propulsion, a variable-pitch propeller is a type of propeller with blades that can be rotated around their long axis to change the blade pitch. Reversible propellers—those where the pitch can be set to negative values—can also ...

tractor

propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...

by a long metal shaft and by another shaft to a smaller marine propeller, similar to those used on

motorboat A motorboat, speedboat or powerboat is a boat that is exclusively powered by an engine. Some motorboats are fitted with inboard motor, inboard engines, others have an outboard motor installed on the rear, containing the internal combustion ...

s, mounted beneath the aircraft's tail. To take off, the pilot would start the engine with the flight propeller feathered and the normal

carburettor A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meteri ...

air intake closed and use a

clutch A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts ...

to engage the tail propeller and get the aircraft moving through the water. The two hydrofoils, mounted beneath the fuselage on struts just forward of the wings similar to the way in which floats were mounted on floatplanes, would cause the P.7 to rise out of the water almost immediately. After the aircraft had risen on its hydrofoils and the flight propeller had cleared the water, the pilot would open the carburettor air intake, again employing the clutch to disengage the marine propeller, and use another clutch to engage the flight propeller, which automatically would switch from feathered to flight pitch. Driven by its flight propeller, the aircraft then would engage in a conventional takeoff, riding on its submerged hydrofoils until it reached takeoff speed. Without the aerodynamic drag induced by floats or the weight they added to the aircraft, Pegna projected that the P.7 would reach high speeds. Sources differ on the speeds he predicted, claiming both 580 km/h (360 mph) and 700 km/h (434.7 mph).

Testing

Piaggio manufactured one P.7 and turned it over to the Italian Schneider Trophy racing team. Although some pilots refused to fly the aircraft, the Italian Schneider teams

Tommaso Dal Molin Tommaso Dal Molin (3 January 1902 – 18 January 1930) was an Italian fighter pilot and internationally prominent seaplane air racer and aerobatic pilot of the 1920s. Biography Dal Molin was born on 3 January 1902 in Molino di Altissimo, a ham ...

conducted some water tests on

Lake Garda Lake Garda ( it, Lago di Garda or ; lmo, label= Eastern Lombard, Lach de Garda; vec, Ƚago de Garda; la, Benacus; grc, Βήνακος) is the largest lake in Italy. It is a popular holiday location in northern Italy, about halfway between ...

in northern Italy. The spray the hydroplanes generated made it difficult to see during takeoff, and persistent problems with both clutches ensued. The aircraft never became airborne. Not ready in time, the P.7 was excluded from the 1929 Schneider Trophy race, in which a

Macchi M.52R The Macchi M.52 was an Italian racing seaplane designed and built by Macchi for the 1927 Schneider Trophy race. The M.52 and a later variant, the M.52bis or M.52R, both set world speed records for seaplanes. Design and development M.52 Mario C ...

and two

Macchi M.67 The Macchi M.67, was an Italian racing seaplane designed by Mario Castoldi and built by Macchi for the 1929 Schneider Trophy race. Design and development Castoldi based the design of the M.67, (a single-seat, low-wing, monoplane, twin-float flo ...

seaplanes represented Italy. Piaggio and Pegna abandoned plans to build a second P.7.

Operators

;

Specifications

Notes

References