The Potez 28 was a French aircraft designed in the 1920s to set distance records, built in both

sesquiplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While a ...

and

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 wings. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

versions. Only two were completed but both set several long distance records.

Design and development

The Potez 28, known also as the Potez 28/2 or the Potez 28 G.R. (''Grands Raids'' or long distance flights, a standard French description of such types) was a close relative of both the Potez 25 and the Potez 25 G.R., all single engine sesquiplanes. In its original

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

form it was particularly like the latter, though strengthened and somewhat enlarged with an upper wingspan increased by 19% to allow for the weight of extra fuel. Unusually for such a large machine, it was a single bay biplane, with two spar wings. The lower wing was both shorter and narrower (55%) in chord than the upper, resulting in it having only 36% of the area. Pairs of

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 leaned outwards and diverged toward the more widely separated upper wing spars. The upper wing was supported over the

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 ...

by further pairs of outward leaning

strut A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. A stay is sometimes used as a synonym for ...

s from the upper fuselage, converging to its spars. The fuselage of the Potez 28 was flat sided, with rounded decking and two 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 placed well behind the upper wing. There was a cut-out in 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. ...

of the upper wing to improve the pilot's field of view. Large external supplementary fuel tanks could be carried below the fuselage to extend the range. The sesquiplane was powered by a

Renault 12Kg Renault S.A., commonly referred to as Groupe Renault ( , , , also known as the Renault Group in English), is a French Multinational corporation, multinational Automotive industry, automobile manufacturer established in 1899. The company curr ...

engine, driving 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 ...

. At the rear the

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 ...

was small and roughly quadrantal, topped by the horn of the

balanced rudder Balanced rudders are used by both ships and aircraft. Both may indicate a portion of the rudder surface ahead of the hinge, placed to lower the control loads needed to turn the rudder. For aircraft the method can also be applied to elevator (air ...

. It had a fixed tail wheel undercarriage with single main wheels mounted on vertical, streamlined, shock absorbing legs attached to the lower fuselage. These were hinged on trailing struts to the outer lower fuselage and on inner struts to its central lower underside. The first Potez 28 was first flown in the first half of 1926. A second Potez 28 was built, powered by a W-12 configuration

Farman 12We The Farman 12We was a French W12 engine, 12-cylinder broad arrow configuration aircraft engine that was designed and built by Farman Aviation Works, Farman in the early 1920s. Power output was 370 kilowatts (500 hp). Design and devel ...

engine. The three cylinder banks each had their own cowlings. During 1927 it was converted into a

, with a

parasol wing 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 wings. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

with an area of , almost the same as the biplane. Its wing had a straight

leading edge The leading edge is the part of the wing that first contacts the air;Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, 1997. alternatively it is the foremost edge of an airfoil sectio ...

but there was straight taper on the

s of the outer panels. The crew of two were now enclosed under a long, continuous canopy. It was test flown in May 1927.

Operational history

The Potez 28 and 28M were built to compete with the Breguet 19 GR over long distances. The Renault engined machine set a new world distance record with a 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 ...

Basra Basra () is a port city in Iraq, southern Iraq. It is the capital of the eponymous Basra Governorate, as well as the List of largest cities of Iraq, third largest city in Iraq overall, behind Baghdad and Mosul. Located near the Iran–Iraq bor ...

, piloted by the brothers Ludovic and Paul Arrachart. Leaving Paris on 26 June they landed at

RAF Shaibah The Royal Air Force (RAF) is the air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the First World War on 1 April 1918, on the merger of the Royal Flying Corps (R ...

, a few kilometers from Basra, with a broken fuel pipe, having covered a distance of in 26 hours 30 min. The Potez 28M set six speed, distance and duration records whilst carrying loads of and over distances between . It was lost during the take-off for a record attempt, a flight from Etampes to

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

, when the weight caused a tyre to burst; the pilots escaped unhurt.

Variants

;Potez 28 G.R.: Sesquiplanes, one powered by a

V-12 engine and the second by a

engine and fitted with oil coolers on the fuselage sides. ;Potez 28/2 Lionel de Marmier-1927

;Potez 28M: Parasol wing monoplane conversion of the second aircraft, powered by the Farman 12We engine.

Specifications (Biplane, Renault engine)

References

{{Potez aircraft 028 1920s French experimental aircraft Sesquiplanes Parasol-wing aircraft Single-engined tractor aircraft Aircraft first flown in 1926