In designing airplanes, unmanned aircraft (UAV), and aeromodelling aircraft, there are quite a variety of aircraft configuration variations such as conventional, tail-boom, tailless, delta and so on.
The number of these variations often makes the dilemma and the debate about which configuration is the best. Therefore, in this article we will discuss a number of airframe configurations, especially those that are a trend among UAVs regarding the advantages and disadvantages of some of these configurations.
a. Tail-aft on Fuselage
This configuration is the most commonly used, so it is not uncommon to be called a conventional configuration. The tail (Empenage) of this configuration in general is in the form of T, Y and V tail.
With a long fuselage, the volume is greater than other configurations, so this configuration is often used for UAVs that require very high endurance to store very much fuel and large sensors.
b. Tail-aft on Booms
The configuration using the tail-boom is quite widely used in UAVs with medium mission distances. The advantage of this configuration is the laying of a driving machine that is close to the center of gravity (CG), making it more stable and easier to set because it is not sensitive to CG.
Then, the empenage location behind the propeller also increases the effectiveness of the control surface (elevator and ruder) so that it is easier to control even at low speeds.
In addition, this configuration allows propellers and machines to be protected during take-off and landing.
This configuration has a horizontal stabilizer far ahead of CG. Unlike the configuration with the tail behind the CG, the horizontal stabilizer in front balances the plane by producing an upward force (lift), so that aerodynamics is more efficient. Then, the wing that is behind also makes stall characteristics better because the stabilizer can be set to stall ahead of the wing.
But because CG is behind, the directional stability (yaw) of this configuration is not good, because giving a vertical stabilizer does not have enough distance to CG so that its effectiveness decreases.
d. Flying wing
This configuration is commonly used by small and medium sized UAVs because of its simplicity, which is structurally advantageous and uses a drive system. In general, the simpler the system, the more reliable it will be.
To achieve longitudinal (pitch) stability, sweep-backs and airfoils that have positive moments are used. In addition, the use of sweep-back also functions to achieve directional stability (yaw).
e. Delta wing
Almost the same as flying wings, which are simple, making this configuration more reliable. In addition, the delta wing shape is also not easily damaged compared to other forms. Even though aerodynamically, the delta shape is less profitable because it produces large induced drag.
This delta shape is usually used also to store parachutes because of the wide cross section of its wings.