Index and first ideas

This is the index of the project's process:

Preliminary design:

• Background
• Similar aircrafts
• Objectives and specifications

Calculations:

• Take-off weight
• Polar
• Performance
• Wings
• Empennage
• Fuselage
•  Centering
• Static and dynamic stability
• Materials
• Flight control system
•  Economic study

Analysis:

• Solid modelling (NX Unigraphics)
• CFD (Vortex Lattice, XFLR5, ANSYS Fluent)
• Structural analysis (ANSYS Structural and Composite PrePost)

Manufacturing:

• Materials
•  Mold
• Machining
• Assembly
• Finish

Flight tests


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(Written on October 17, 2014)

First steps, conceptual design:

For the aircraft design several ideas are going to be taken from many different designs of RC planes in the market.

This is to start modelling the fuselage form and the aircraft configuration for the wings, empennage and power plant.

The specification of this plane is for recreational flight, nor acrobatic neither competition. One important characteristic is the high aerodynamic efficiency, with increased wing surface to act as a glider when it has gained altitude.
Another possibility to be studied is the implementation of a camera in the fuselage to transmit live the view from the cockpit, which can be seen in a screen in the controller. The maximum wingspan is set to 3 meters because of manufacturing reasons. The plane has a constant weight payload consisting of the signal receiver, the battery, the control system (PCB, servomechanisms, gyroscopes) and an electric motor. This engine can be used for climbing or retake flight in case of stall or quick loss of altitude.
High aerodynamic efficiency allows a slower flight speed, better for professional aerial filming, and it counteracts the effect of adding a camera on the fuselage, which creates a lot of drag. If the purpose is to record the view, larger wings make it more steady, regardless of using the motor or not.

The point is for increasing its versatility. It mixes the advantages of a glider to an RC and it also adds the multiple uses of a first-person view flight. Away from the plane, a radio transmitter system will be needed too.

Wikipedia: “Powered gliders have recently seen an increase in popularity. By combining the efficient wing size and wide speed envelope of a glider airframe with an electric motor, it is possible to achieve long flight times and high carrying capacity, as well as glide in any suitable location regardless of thermals or lift. A common method of maximizing flight duration is to quickly fly a powered glider upwards to a chosen altitude and descending in an unpowered glide. Folding propellers which reduce drag (as well as the risk of breaking the propeller) are standard. Powered gliders built with stability in mind and capable of aerobatics, high speed flight and sustained vertical flight are classified as 'Hot-liners'. 'Warm-liners' are powered craft with similar abilities but less extreme thrust capability. Many powered beginner craft are based upon or considered borderline gliders.”

A good use a sailplane with a camera could have is to spy areas from above without the noise of the engine alerting those on the ground. As it is a glider it can stay in the air during long periods of time saving battery and avoiding noise alert.

Wikipedia: “First-person view (FPV) flight is a type of remote-control flying that has grown in popularity in recent years. It involves mounting a small video camera and television transmitter on an RC aircraft and flying by means of a live video down-link, commonly displayed on video goggles or a portable LCD screen. When flying FPV, the pilot sees from the aircraft's perspective, and does not even have to look at the model. As a result, FPV aircraft can be flown well beyond visual range, limited only by the range of the remote control and video transmitter. Video transmitters typically operate at a power level between 200 mW and 1500 mW. The most common frequencies used for video transmission are 900 MHz, 1.2 GHz, 2.4 GHz, and 5.8 GHz.^[6] Specialized long-range UHF control systems operating at 433 MHz (for amateur radio licensees only) or 869 MHz^[6] are commonly used to achieve greater control range, while the use of directional, high-gain antennas increases video range. Sophisticated setups are capable of achieving a range of 20–30 miles or more.^[7] FPV aircraft are frequently used for aerial photography and videography, and many videos of FPV flights can be found on popular video sites such as YouTube and Vimeo.

A basic FPV system consists of a camera, video transmitter, video receiver, and a display. More advanced setups commonly add in specialized hardware, including on-screen displays with GPS navigation and flight data, stabilization systems, and autopilot devices with "return to home" capability—allowing the aircraft to fly back to its starting point on its own in the event of signal loss. On-board cameras can be equipped with a pan and tilt mount, which when coupled with video goggles and "head tracking" devices creates a truly immersive, first-person experience, as if the pilot was actually sitting in the cockpit of the RC aircraft.^[6]

Both helicopters and fixed-wing RC aircraft are used for FPV flight. The most commonly chosen airframes for FPV planes are larger models with sufficient payload space for the video equipment and large wings capable of supporting the extra weight. Pusher-propeller planes are preferred so that the propeller is not in view of the camera. Flying wing designs are also popular for FPV, as they provide a good combination of large wing surface area, speed, maneuverability, and gliding ability”.

State range.

State materials.