The Peyret-Nessler Libellule (Dragonfly) was a French two-seat, low-powered ()

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 ...

light aircraft built in 1927 to provide practical but economical flying. It was one of the first of these French ''avionettes''.

Design and development

Eric Nessler was well known as a French glider pilot and builder in the inter-war period and Louis Peyret was an experienced aircraft designer and constructor. Peyret had designed and built the

tandem wing QAC Quickie Q2 A tandem wing is a wing configuration in which a flying craft or animal has two or more sets of wings set one behind another. All the wings contribute to lift. The tandem wing is distinct from the biplane in which the wings are ...

Peyret Alérion glider which won the first British gliding contest in 1922 and had also frequently collaborated with others, the Peyret-Le Prieur seaplane being one example. When Nessler began to consider the design of a very low-powered two-seat lightplane, Peyret was a natural choice of partner. The intention was to produce a practical aircraft with costs no greater than those of a car. The three part

of the Libellule was rectangular in plan and without dihedral. Built around two

box spars A box (plural: boxes) is a container with rigid sides used for the storage or transportation of its contents. Most boxes have flat, parallel, rectangular sides (typically rectangular prisms). Boxes can be very small (like a matchbox) or very ...

, its centre section was held high above 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 pairs of parallel, outward-leaning struts from the spars at its extremities to the upper fuselage

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 and the outer panels were braced with

duraluminum Duralumin (also called duraluminum, duraluminium, duralum, dural(l)ium, or dural) is a trade name for one of the earliest types of age-hardenable aluminium–copper alloys. The term is a combination of ''Düren'' and ''aluminium'' . Its use as ...

V-struts from the lower longerons out to the spars at about 60% span. The wing position had the advantage of keeping it largely clear of the

prop wash A prop, formally known as a (theatrical) property, is an object actors use on stage or screen during a performance or screen production. In practical terms, a prop is considered to be anything movable or portable on a stage or a set, distinct ...

and, by lowering the centre of gravity, increasing lateral stability. The centre section was entirely covered with Rhodoïd, a transparent material used to provide an uninterrupted upward view from the

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, and the outer panels covered with

fabric Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, and different types of fabric. At first, the word "textiles" only referred to woven fabrics. However, weaving is no ...

. The Libellule's unusual

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 roll (or movement around ...

, designed by Peyret, ran from the tips to about mid-span; mounted on the rear spar, they were divided span-wise into two roughly equal chord parts, hinged together and interconnected so that the rear surface had a greater deflection than the forward one, particularly in the case of upward deflections. The intention was to retain lateral control down to the lowest speeds. The Libellule was powered by a Salmson AD.3 three-cylinder

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. ...

within an aluminium

cowling A cowling (or cowl) is the removable covering of a vehicle's engine, most often found on automobiles, motorcycles, airplanes, and on outboard boat motors. On airplanes, cowlings are used to reduce drag and to cool the engine. On boats, cowlings ...

through which the cylinder heads projected for cooling. Behind the engine the wooden fuselage had a rectangular section, formed by four longerons with a series of frames. It was covered with thick

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 ...

in the cockpit area under the wing but only thick further aft. Below the wing there was a single cockpit, long, with

tandem Tandem, or in tandem, is an arrangement in which two or more animals, machines, or people are lined up one behind another, all facing in the same direction. ''Tandem'' can also be used more generally to refer to any group of persons or objects w ...

seats for the pilot and his passenger behind. The passenger had a headrest which formed the start of an upper fuselage fairing, fabric-covered and running back to the tail. The vertical tail was

rhomboidal Traditionally, in two-dimensional geometry, a rhomboid is a parallelogram in which adjacent sides are of unequal lengths and angles are non-right angled. The terms "rhomboid" and "parallelogram" are often erroneously conflated with each oth ...

in profile, with an unbalanced rudder. The horizontal tail was rectangular in plan and, like the ailerons, split spanwise into two moving sections with greater deflections at the rear. The Libellule's

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for taxiing, takeoff or landing. For aircraft, it is generally needed for all three of these. It was also formerly called ''alighting gear'' by some manufacturers, s ...

was fixed and conventional with a track of . Its mainwheels were on a single axle, connected to the central and lower fuselage with a lateral, inverted, W-strut of profiled steel tubes, with rubber cord shock absorbers. Drag loads were countered with fore-and-aft wire bracing.

Operational history

The sole Libellule was first flown in mid-December 1927 and in June 1928 gained its certificate of airworthiness. At the end of June it was displayed at

Orly Orly () is a commune in the southern suburbs of Paris, Île-de-France. It is located from the center of Paris. The name of Orly came from Latin ''Aureliacum'', "the villa of Aurelius". Orly Airport partially lies on the territory of the c ...

by Nessler and it returned there again in September for the light plane meeting. There were frequent discussions in France about the merits of low-power aircraft (''avionettes'' in French) which cited the Libellue as an exemplar of the type. In 1930 it was offered for sale at a price of 35,000 francs and it remained active until at least late 1934.

Specifications

References

{{Peyret aircraft Parasol-wing aircraft 1920s French sport aircraft Peyret aircraft Single-engined tractor aircraft Aircraft first flown in 1927