HOME

TheInfoList



OR:

The Potez VIII was a French
training aircraft A trainer is a class of aircraft designed specifically to facilitate flight training of pilots and aircrews. The use of a dedicated trainer aircraft with additional safety features—such as tandem flight controls, forgiving flight characteristic ...
which first flew in 1920. Originally it had a very unusual vertical inline engine and a four-wheeled
undercarriage Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include: *The landing gear of an aircraft. *The ch ...
, though the production version was more conventional.


Design and development

The Potez VIII as first displayed, unflown, at the 1919 Paris Salon was a conventional small, single engine aircraft of its time apart from a most unusual engine and an unconventional undercarriage. It was a single bay biplane with rectangular plan wings mounted without stagger but with marked dihedral and braced with pair of parallel,
airfoil An airfoil (American English) or aerofoil (British English) is a streamlined body that is capable of generating significantly more Lift (force), lift than Drag (physics), drag. Wings, sails and propeller blades are examples of airfoils. Foil (fl ...
section
interplane strut In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of struts, which act in ...
s. A pair of inverted V
cabane strut In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of struts, which act in ...
s, parallel to each other, joined the central section of the upper wing to the upper
fuselage The fuselage (; from the French language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...
longeron In engineering, a longeron or stringer is a load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural fram ...
s. There were
aileron An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement aroun ...
s on the upper wing only. The wings were
duralumin Duralumin (also called duraluminum, duraluminium, duralum, dural(l)ium, or dural) is a trade name for one of the earliest types of age hardening, age-hardenable aluminium–copper alloys. The term is a combination of ''Düren'' and ''aluminium'' ...
two spar structures with fabric covering. The Potez VIII had a simple, flat-sided fuselage with a wooden structure and
plywood Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboa ...
skinning. There were tandem open
cockpit A cockpit or flight deck is the area, on the front part of an aircraft, spacecraft, or submersible, from which a pilot controls the vehicle. The cockpit of an aircraft contains flight instruments on an instrument panel, and the controls th ...
s, the forward one under the upper wing, which was mounted well above it, and the other just aft of the
trailing edge The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 1997. ...
, which had a rounded cut-out to assist the pilot's upward vision. The
empennage The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow.Crane, Dale: ''Dictionary of Aeronautical Terms, third ed ...
was conventional, with a
tailplane A tailplane, also known as a horizontal stabilizer, is a small lift (force), lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters ...
on the upper fuselage and a broad chord, swept-edge
fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. F ...
wire braced to it. The tail structure was similar to that of the wing, with a metal frame and fabric covering. The engine of the 1919 aircraft was also a Potez design, the A-4. This was a four-cylinder inline built to run with its crankshaft vertical. It was mounted with its exposed cylinders pointing forwards for cooling and had gearing that turned the output through 90° to drive a two-blade
propeller A propeller (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 a working flu ...
. Although the Potez A-4 was unsuccessful, its configuration produced the high power line and low
centre of gravity In physics, the center of mass of a distribution of mass in space (sometimes referred to as the barycenter or balance point) is the unique point at any given time where the weighted relative position of the distributed mass sums to zero. For a ...
of later inverted inline engines, allowing a shorter undercarriage, easier access to the cockpits and a better forward view over a shorter, lower nose than its inline contemporaries. The high propeller shaft also allowed a shorter undercarriage; a four-wheeled unit protected the propeller tips from contact with the ground. The A-4 engined Potez VIII first flew on 19 April 1920. When its engine was recognised as a failure the A-4 was replaced by a six-cylinder
Anzani Anzani was an engine manufacturer founded by the Italian Alessandro Anzani (1877–1956), which produced proprietary engines for aircraft, cars, boats, and motorcycles in factories in Britain, France and Italy. Overview From his native Italy, ...
radial engine The radial engine is a reciprocating engine, reciprocating type internal combustion engine, internal combustion engine configuration in which the cylinder (engine), cylinders "radiate" outward from a central crankcase like the spokes of a wheel. ...
, mounted uncowled in the nose. An early version produced and a later variant . Initially the four wheel undercarriage was retained but when the Potez VIII appeared at the 1922 Paris Salon it had more conventional two wheel gear. The wheels were on a single axle. From each end of the axle a strut ran to the underside of the forward fuselage, acting together with a vertical telescopic, rubber damped
shock absorber A shock absorber or damper is a mechanical or hydraulics, hydraulic device designed to absorb and Damping ratio, damp shock (mechanics), shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typic ...
. At least one example flew as a
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, ...
, designated Potez VIII H (H for ''hydravion'' or water plane). It had a single, central float and a small, airfoil section stabilizing float under each wing. A side-by-side version was also built and designated the Potez VIII R; it was a little heavier, with a wider fuselage and powered by a fully cowled Le Rhone 9C engine. It returned to the four wheel undercarriage. Reconstructed pre-
World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
civil registers suggest about fifteen powered Potez VIIIs were built. There was also a glider version, the Potez VIII P (P for ''planeur'' or glider) with a smooth aluminium nosecap in place of the engine. This was slightly () longer and lighter with an empty weight of compared with the of the Anzani powered version. It was the overall winner at the First Glider Congress, held in
Clermont-Ferrand Clermont-Ferrand (, , ; or simply ; ) is a city and Communes of France, commune of France, in the Auvergne-Rhône-Alpes regions of France, region, with a population of 147,284 (2020). Its metropolitan area () had 504,157 inhabitants at the 2018 ...
, which ended on 30 August 1922. The powered version also had competition success, coming second in the first ''La Coupe de Consummation d'Aviation Zénith'' (The Zénith Cup for Aircraft Fuel Consumption), based on a return flight from
Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
to
Lyon Lyon (Franco-Provençal: ''Liyon'') is a city in France. It is located at the confluence of the rivers Rhône and Saône, to the northwest of the French Alps, southeast of Paris, north of Marseille, southwest of Geneva, Switzerland, north ...
flown over 21–22 August 1923. The deciding parameter was the ratio of weight of fuel used to payload. The Potez scored 0.616, the winner, a Farman F.90, 0.473. Four Potez VIIIs were registered in
Bulgaria Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...
.


Variants

;VIII prototype: Potez A-4 engine, . ;VIII:
Anzani 6A Anzani was an engine manufacturer founded by the Italians, Italian Alessandro Anzani (1877–1956), which produced Property, proprietary engines for aircraft, Automobile, cars, boats, and motorcycles in factories in United Kingdom, Britain, Fra ...
engine, ;VIIIA:Anzani 6A engine, . ;VIII H:Floatplane. ;VIII P:Glider. ;VIII R: Side by side seating,
Le Rhône 9C The Le Rhône 9C is a nine-cylinder Rotary engine, rotary aircraft engine produced in France by '' Société des Moteurs Le Rhône'' / Gnome et Rhône. Also known as the Le Rhône 80 hp in a reference to its nominal power rating, t ...
engine, .


Specifications (70 hp Anzani)


References


Bibliography

* * * {{Potez aircraft 1920s French civil trainer aircraft 1920s French sport aircraft 1920s French sailplanes R08 Biplanes Single-engined tractor aircraft Aircraft first flown in 1920 Glider aircraft