- Priority to woodworking
- Careful assemblies
- Plans followed to the letter
- Wings: the stages of construction
- Cockpit and structural part
- Cover the structure
- Make the hood
- The reservoir
- The dashboard
- A question of balance
- The cockpit canopy
- Painting: in red and white
- Running tests
- Last checks before takeoff
- Ready for take off
It took Patrick Desire and his son four years to build the plane of their dreams. And satiate a common passion: flying. A methodical construction where every element has been verified to ensure the pleasure in complete safety.
His passion for aviation, Patrick Desire cultivated it first with the construction of models. Then chance is involved: " After a move, almost twenty years ago, I spent twice a day in front of an airfield, located between my workplace and my home... I stopped there and passed my pilot's license. Over time, our reader, an engineer from Arts et Métiers, and other enthusiasts decided to build a plane for the club. " The plane took flight in 2000 and it still flies! But the result is far from satisfying his passion. " This first experience made me want to achieve something for me. "Especially since one of these sons, too," caught the virus ". They embark together on the adventure. It will last four years and required a budget of € 23,000...
Priority to woodworking
If thoroughness, rigor and patience are among the qualities required to carry out such an undertaking, particular qualifications seem a priori indispensable. Safety, among other things, is a decisive factor: to fly, all aircraft must be declared to the General Directorate of Civil Aviation (DGCA). But for our reader, the operation is less complex than it seems: " It is a relatively simple construction to make for a good handyman. We must also love working with wood. Luckily, Patrick Desire's other passion is carpentry! The first question to ask before embarking is: what kind of aircraft do we want to achieve? " For this kind of project, two options are possible. Either we do everything ourselves, or we use available plans. Our reader chooses the second solution: " The plans were provided to me by the Air Sports Network (RSA). You have to study everything: the fuselage, the wings, the movement controls, the electrical wiring... A methodical review, which requires a lot of time.
The study of plans digested ", The construction of the aircraft begins with the realization of the wings and the" cell "(The cockpit and the structural part of the plane). The pieces of wood are cut and glued together to form subassemblies, in turn assembled. The quality of the wood is essential: « The structure is made of Oregon pine, a species with low weight and good flexural strength, two important characteristics. I also used plywood for the aerospace industry. They have more folds, which gives them great rigidity. Glues are also specific to aircraft construction. Another key element: " In case of problem, I kept "test pieces" (parts used for a test, Editor's note). »
Rigidity is provided by the Dacron fabric (polyester fiber): " Glued to the structure, it is then stretched by heating it with an iron. It remains to install the engine, to manufacture the dashboard, the landing gear... Comes the time of the first tests, " with the beating heart ". Then finally the first flight. The words give way to the only moment now...
Plans followed to the letter
The plans provided by the RSA Federation (Air Sports Network) required a long period of study. Wings, fuselage, wiring... everything has been meticulously examined.
Wings: the stages of construction
The construction of the wings took place in several stages: "It is about a assembly in three dimensions", explains Patrick Desire. "Couples" are connected by slats that serve as reinforcements and fasteners. Sizing with special glues is essential for holding the set. A cabinetmaker's work...
Cockpit and structural part
The " cell "Bringing together the cabin and the structural part of the plane, is also entirely made of wood. The Oregon pine cleats (18 x 18 mm section) are assembled in lattice. Other hardwoods are used, such as beech for the anchoring points of the wings on the cell.
Cover the structure
The pine structure of the cabin is covered with a plywood used in aeronautics from 3 to 5 mm. Everything is calculated to the millimeter. The weight is also checked: to obtain the classification ULM (ultra light motorized), the whole must not exceed 270 kg without passenger, and up to 450 kg with. Gold " we tend to increase the section of parts at the expense of weight Our reader says.
The sizing is " an important step and a real moment of conviviality because we were four to achieve it, "recalls our reader. After drying the glue applied to wood, the cut fabric is positioned and fixed by "dabbing" a brush lined with glue on the surface; glue that "must cross the canvas to reactivate that previously deposited on the wood. The heat-shrinkable fabric was stretched with an iron. A crucial step, which allows
to stiffen the whole: " There is a small technical gesture to acquire. The goal is to stretch the canvas like a drum skin. »
The centerpiece of the 80 HP four-cylinder engine is new for safety reasons. " It is positioned at a certain angle to counter the gyro effect. The axis of the crankshaft is not parallel to that of the fuselage. It is welded very rigid steel tubes (25 Cd 45), bolted in the wooden structure.
Make the hood
Due to its lightness, the engine hood is made to measure in polyester resin. Designed by our reader, the mold has been adapted to the engine configuration. A complex piece, in one piece with access hatch, impossible to build plywood, and whose realization requires extreme precision.
The tank is the object of all attention. " This piece requires seriousness. It is necessary to call on a specialist who knows how to weld the aluminum sheet. »
In folded sheet metal, the dashboard is made to measure. Everything is installed according to the electric diagram. Most instruments, new or used, come from the automotive industry.
A question of balance
"Un plane is a bit like a scale, there is a point of balance to reach Says Patrick Desire.
For example the battery - a small red box in the fuselage - helps to balance the whole.
The cockpit canopy
The cockpit canopy must provide almost panoramic vision. Purchased new, it is mounted on a wooden structure and pivots on one axis: a pneumatic cylinder of car trunk keeps it open; it closes securely thanks to a toggle lock. Bolted to the cell, the landing gear is made using a bent aluminum plate, for a question of weight. New wheels are equipped with disc brakes.
Painting: in red and white
Assisted by one of his passionate aviation sons, our reader sprays two coats of paint for the aviation industry on wood and canvas. The colors selected are red and white.
The time of the first tests of rolling "to take the plane in hand", tells Patrick Désire. Preludes to the big jump, flea jumps « to see his behavior during take-off and landing ».
Last checks before takeoff
The arrival of the plane on the airfield, a great moment of emotion. A step where you also have to go up the wings and check one last time all assemblies, security requires.
Ready for take off
The time has come to tie the belts!