Modern aircraft usually have two sets of ailerons, one inboard and one outboard, to enhance the aerodynamic performance and control of the aircraft. There are a few reasons for this configuration:
1. Roll Control: Ailerons are control surfaces that are used to control the roll of the aircraft. By deflecting the ailerons, one up and one down, the aircraft can generate differential lift on each wing, creating a rolling motion. Having a set of inboard and outboard ailerons allows for greater control authority and effectiveness in maneuvering the aircraft.
2. Wing Flexibility: The outboard sections of the wing are generally more flexible compared to the inboard sections. This flexibility can cause a phenomenon called wingtip vortex, which can affect the aircraft's efficiency and stability. By having an outboard aileron, the aircraft can counteract the wingtip vortex and maintain better control over the aircraft's roll.
3. Spanwise Lift Distribution: An aircraft's wings generate lift, and the distribution of lift across the wings is crucial for stability and control. The use of both inboard and outboard ailerons allows for a more balanced spanwise lift distribution, improving the overall stability and control characteristics of the aircraft.
4. Redundancy: Having two sets of ailerons adds redundancy to the aircraft's control system. In the event of a failure or damage to one set of ailerons, the other set can still provide some level of control over the aircraft's roll.
Overall, the presence of both inboard and outboard ailerons on modern aircraft improves maneuverability, stability, and redundancy, providing pilots with better control over the aircraft in various flight conditions.
Modern aircraft usually have two sets of ailerons: one 'inboard aileron' (close to the fuselage) and one 'outboard aileron' (further up the wing). Why is this?
3 answers
The two sets of ailerons are used for different flight speeds.
The two sets of ailerons are used for different flight speeds, here is why:
As you know, the moment caused by a force is given by M=Fr , where F is the force and r is the moment arm. At low speeds, the force by an aileron is relatively low, so to get a sufficient moment the moment arm should be large. Hence at low speeds, the outboard ailerons are used.
At high speeds the force by an aileron is very large, if the outboard ailerons would be used to moment (and loads on the wing structure) would become very big. Hence at high speeds the inboard ailerons are used, to keep the banking moment within bounds.
The two sets of ailerons are used for different flight speeds, here is why:
As you know, the moment caused by a force is given by M=Fr , where F is the force and r is the moment arm. At low speeds, the force by an aileron is relatively low, so to get a sufficient moment the moment arm should be large. Hence at low speeds, the outboard ailerons are used.
At high speeds the force by an aileron is very large, if the outboard ailerons would be used to moment (and loads on the wing structure) would become very big. Hence at high speeds the inboard ailerons are used, to keep the banking moment within bounds.
The above explanation suggests that the different sets of ailerons are used for different flight speeds to optimize the moment arm and control the banking moment of the aircraft.
At low speeds, the forces generated by the ailerons are relatively small. To achieve a sufficient moment (the twisting force that causes the aircraft to roll), the moment arm needs to be larger. Therefore, the outboard ailerons, which are further away from the centerline of the aircraft (fuselage), are used. This allows for a longer moment arm, enabling the aircraft to generate enough rolling moment at lower speeds.
On the other hand, at high speeds, the forces exerted on the ailerons are significantly larger. If the outboard ailerons were used at high speeds, the resulting moments and loads on the wing structure would become excessive. To prevent these forces from exceeding the aircraft's design limits, the inboard ailerons, closer to the fuselage, are utilized. By using the inboard ailerons, the banking moment can be controlled and kept within acceptable bounds, ensuring the structural integrity of the wing and the aircraft as a whole remains intact at higher speeds.
In summary, the use of different sets of ailerons for different flight speeds helps optimize the moment arm and prevent excessive loads on the aircraft's structure, ensuring safe and efficient control of the aircraft across a wide range of speeds.
At low speeds, the forces generated by the ailerons are relatively small. To achieve a sufficient moment (the twisting force that causes the aircraft to roll), the moment arm needs to be larger. Therefore, the outboard ailerons, which are further away from the centerline of the aircraft (fuselage), are used. This allows for a longer moment arm, enabling the aircraft to generate enough rolling moment at lower speeds.
On the other hand, at high speeds, the forces exerted on the ailerons are significantly larger. If the outboard ailerons were used at high speeds, the resulting moments and loads on the wing structure would become excessive. To prevent these forces from exceeding the aircraft's design limits, the inboard ailerons, closer to the fuselage, are utilized. By using the inboard ailerons, the banking moment can be controlled and kept within acceptable bounds, ensuring the structural integrity of the wing and the aircraft as a whole remains intact at higher speeds.
In summary, the use of different sets of ailerons for different flight speeds helps optimize the moment arm and prevent excessive loads on the aircraft's structure, ensuring safe and efficient control of the aircraft across a wide range of speeds.
3 answers