The Bodiansky 20, a

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

four-seat touring aircraft flown in the early 1930s, was one of the first French aircraft to adopt Handley Page slots to delay the stall and lower landing speed.

Design and development

Though the Handley Page H.P.20 had demonstrated the efficacy of leading edge slots used in coordination with flaps in delaying the onset of stall at high

angles of attack In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a reference line on a body (often the chord line of an airfoil) and the vector representing the relative motion between the body and the fluid through which it is m ...

in 1921, they were only adopted slowly across

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. The

Handley Page Gugnunc The Handley Page H.P.39 is a wooden biplane that was constructed in 1929. The aircraft was intended to compete in a competition proposed by the Daniel Guggenheim Fund for the Promotion of Aeronautics - the Guggenheim Safe Aircraft Competition ...

of 1929 had two groups of slots, one which opened with the flaps and the other automatically opened by air pressure changes as the stall approached. The Bodiansky 20 was one of the first

aircraft to use this system. It was also the first French aircraft to have a welded steel tube

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

structure, made in the factory of the aircraft constructor S. Poite. The

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 canti ...

wing of the Bodiansky 20 was built in three parts, with a short-span, thick, rectangular plan central section and nearly triangular plan outer panels which carried 8° of dihedral and thinned linearly outwards. The aspect ratio of the wing, 10.9, was high. Structurally the central section was a welded steel tube part of the fuselage and the outer panels were wooden, each with two

spar SPAR, originally DESPAR, styled as DE SPAR, is a Dutch multinational that provides branding, supplies and support services for independently owned and operated food retail stores. It was founded in the Netherlands in 1932, by Adriaan van Well, ...

s and

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

skinned.

Slats Super Low Altitude Test Satellite (SLATS) or Tsubame was a JAXA satellite intended to demonstrate operations in very low Earth orbit (VLEO, below 200 km), using ion engines to counteract aerodynamic drag from the Earth's atmosphere which i ...

, which opened to form the slots, filled the whole

leading edge The leading edge of an airfoil surface such as a wing is its foremost edge and is therefore the part which first meets the oncoming air.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, ...

s of the outer panels and were divided into two sections. These sections matched the division 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. ...

into

ailerons 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 Flight dynamics, roll (or ...

outboard and flaps inboard. The outer slots opened automatically on the approach of the stall, whereas the inboard slats deployed when the flaps were lowered to their single down setting. It was powered by a nose-mounted,

Renault 4Pb The Renault 4P, also called the Renault Bengali Junior, was a series of air-cooled 4-cylinder inverted inline aero engines designed and built in France from 1927, which produced from to . Design and development Charles Lindbergh's Atlantic Ocea ...

, a four-cylinder, air-cooled, upright inline engine, though its mountings, part of the tubular fuselage structure, could accept engines with powers in the range . The exhaust was fitted with a silencer and its outlet was aft of the cabin. Fuel was held in two tanks in the wing centre-section and oil in the fuselage aft of the engine firewall. Its enclosed cabin, entered via centrally hinged, multi-part glazing, had two forward seats, equipped with dual controls, and a rear bench seat. It was normally flown from the left-hand seat, where the rudder bar was fitted with brake pedals. The flap lever was placed centrally. The fuselage was fabric covered apart from the engine area and the sloping fuselage roof and upper part aft of the cabin, which was covered with electron metal sheet. The tail of the Bodiansky 20 was conventional, with a small, triangular, in-flight adjustable

tailplane A tailplane, also known as a horizontal stabiliser, is a small 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 and gyroplane ...

mounted at the top of the fuselage frame. It carried generous, aerodynamically balanced

elevator An elevator or lift is a wire rope, cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or deck (building), decks of a building, watercraft, ...

s with a semi-elliptical trailing edge and was fitted with ground-adjustable

trim tab Trim tabs are small surfaces connected to the trailing edge of a larger control surface on a boat or aircraft, used to control the trim of the controls, i.e. to counteract hydro- or aerodynamic forces and stabilise the boat or aircraft in a pa ...

s. The vertical tail was similar in profile and design to the horizontal surfaces; the

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...

extended to the keel and worked in a deep elevator cut-out. Structurally these surfaces were steel tube framed and fabric covered. It had fixed tailwheel

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...

with a track of . The mainwheels, equipped with brakes, were independently mounted on bent axles hinged from the central fuselage and restrained by drag struts from the forward lower fuselage frames. Each wheel had a short, vertical

oleo strut An oleo strut is a pneumatic air–oil hydraulic shock absorber used on the landing gear of most large aircraft and many smaller ones. This design cushions the impacts of landing and damps out vertical oscillations. It is undesirable for an airp ...

from the forward part of the outer end of the wing centre-section. The tailwheel castored and was sprung and damped with rubber rings. The Bodiansky 2 first flew on 6 July 1931. Only one, registered ''F-ALZB'', was built and its subsequent history in unknown.

Specifications

References

{{reflist, refs= {{cite book , title= Handley Page Aircraft since 1907, last= Barnes, first=C.H. , last2=James, first2=D. N., year=1987 , publisher=Putnam Publishing , location=London , isbn= 0 85177 803 8, pages= {{cite journal , last=Frachet , first=André , date=2 July 1931, title=Le monoplan à fentes Bodiansky, journal=Les Ailes, issue=524 , pages=3, url=http://gallica.bnf.fr/ark:/12148/bpt6k6555773n/f3 {{cite journal , last=Bernard , first=Martin , last2=Sparrow, first2=Dave, last3=Espérou, first3=Bernard , date=September 2014 , title=F-1922 - The French Civil Register from 1922, journal= Air Britain Archive, pages=2014/125 {{cite web , url= https://www.aviafrance.com/bodiansky-20-aviation-france-9924.htm, title=Bodiansky 20 , author=Bruno Parmentier , date=20 August 2005 , accessdate=10 November 2016 1930s French civil utility aircraft Single-engined tractor aircraft Aircraft first flown in 1931