Fournier RF-4D, Wingspan 2815mm, GRP fuselage - Ribbed wing
Aeronaut # 135501

The Fournier RF-4D model, popular for many years, is now equipped with ribbed wings.
The wings are built with precisely laser-cut components on the well-known aero-naut jig, which allows for quick and warp-free assembly. Sophisticated auxiliary templates aim for precise and swift construction.
The wings are planked with pre-cut maple veneer, which has been bonded with a special textile fiber to achieve easy processing and high durability. The material, called A-Tex, is a product manufactured by aero-naut itself and is used in many aero-naut kits.
The 3D-style construction manual, typical for aero-naut, enables step-by-step assembly and supports the model builder with 3D drawings and detailed text. This makes assembly easy.

The model was designed at a scale of 1:4 so that retractable landing gear and airbrakes could also be installed. Moderate aerobatics are possible with the Fournier. Loops flown with feeling, effective turns, rolls, etc., are no problem.
Long approaches can be precisely controlled with the help of the airbrakes. The wing is two-part and has a connection made of an 18mm duralumin tube; the horizontal stabilizer is mounted on carbon tubes and firmly glued to the fuselage. Access to the RC equipment is provided by a large cutout on the fuselage bottom. The wing locking mechanism is also accessible here.
The GRP fuselage is made to aero-naut's usual high quality and has moldings and all penetrations for wings and horizontal stabilizer. The horizontally divided, two-part GRP cowl already has guides for centering both parts.
The cockpit interior is based on the original; these parts are made of ABS. The construction manual provides further tips on how to design the interior (e.g., upholstery).
The sprung retractable landing gear with hollow rubber tires was specially developed for this model. The duralumin and steel parts are precisely waterjet cut, hard-soldered, and powder-coated. The landing gear retracts into an ABS fender built into the fuselage. The pneumatic retractable landing gear control with an 18mm diameter (bore) compressed air cylinder is designed as single-acting. This is an important contribution to safety, as in the event of a pressure loss in the system, the landing gear is automatically extended! Included, among other things, is an adjustable pressure reducer, with which the timing of the retraction and extension can be adjusted to "scale". The control valve is also designed as single-acting; actuation is done by pressing a cam (lobe) mounted on, for example, a (mini) servo, while a coil spring handles the extension. Only a hand pump with a pressure gauge (e.g., from Robart) is not included.

The model kit contains:

• Detailed 3D construction manual
• GRP fuselage and cowl
• Wing kit made of laser-cut wooden parts (incl. A-Tex planking)
• Airbrakes, spinner, retractable landing gear and outrigger wheels, tail skid, dummy exhausts and filler necks
• Canopy
• ABS parts
• CNC-milled plywood and GRP parts
• Stamped parts
• Duralumin tube, GRP tube (connection guide)
• Wing locking mechanism
• Small parts set
• The construction of the wings is simplified and warp-free by the well-known aero-naut jig made of Depron