Questions tagged [control-surfaces]
Use for control surfaces; for the cockpit controls, use [flight-controls] instead.
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Why isn't the rudder below the tail?
Most airplanes have a rudder on top of the tail. When it is turned to the left, it causes the plane to yaw to the left. But it also puts a roll force to the right, because it is usually above the ...
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How are flaps and the elevator positioned in cruise?
so I understand that an elevator is used to maintain cruise (straight level and unaccelerated flight) but I’m curious now about how the flaps and elevator is positioned whilst an aeroplane is trying ...
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Boeing 777 PCU Synchronization of Duplicate Hydraulic Actuators for Control Surface Deflection
I have a question regarding the redundancy of hydraulic systems used to deflect the control surfaces of a Boeing 777 aircraft (or the like). We know that "the elevators, ailerons, and flaperons ...
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How do rolling airframe missiles steer?
There are a certain type of missiles that roll constantly in flight, so-called rolling airframe missiles. Missiles found in the category range from various MANPADs, to the creatively named RIM-116 ...
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Why does the trailing edge have a more pronounced taper than the leading edge on the Cessna 172?
Why does the Cessna 172 have a more pronounced taper on the trailing edge as opposed to the leading edge?
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What causes the "dead band" phenomenon during takeoff on the Boeing 737?
During takeoff, the Boeing 737 encounters a distinctive "dead band" phenomenon after the initial pitch reaches approximately 10 degrees. Essentially, a slight increase in back pressure is ...
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Are flaps regulated as balanced control surfaces?
I was talking about flutter the other day and how it occurs with the ailerons able to flap out of sync with the wing. I realized that the flaps, could in theory, move in a similar way. However, the ...
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How do hybrid control surfaces work?
I am trying to build a self-stabilized model rocket with actuated fins. Suppose the rocket has 4 fins. The diagonal fins must rotate together to control the yaw/pitch motion, and all the fins are ...
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Control surfaces on radio-control models of airliners
Do large RC airliners like the huge Emirates RC A380 still need all the same control surfaces that a real A380 has I,e leading edge slats? If not why is this the case.
Many thanks for your time in ...
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Why were the Space Shuttle's elevons reversed, early in re-entry?
The veteran Space Shuttle commander Charlie Precourt writes, in the July 2022 issue of EAA's Sport Aviation, p. 38:
Another interesting reality about our flight controls was their
working essentially ...
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Are spoilers primary or secondary flight control surfaces?
The literature on primary and secondary flight controls is very contradictory.
My professor provided this image from which I infer that spoilers are used for primary flight control:
Also, here it ...
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Could a trim system conceivably manipulate only primary surfaces?
Most airplanes' trim systems manipulate a tab associated with a primary surface. For example, a pitch trim tab (secondary surface) is attached to the elevators (primary surface) and will change the ...
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What about measuring airspeed from control surface forces on the framework?
I watch a lot of these videos that people make about air disasters.
One factor that seems (or hopefully seemed) to crop up is where pilots get hopelessly confused about airspeed, particularly (it ...
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Why are the red/white control surfaces under the wing extended during a take off?
These pictures are more than a little dated as the CF-101 Voodoo's have not been flown since the mid 80's. In these two photos we can see the Voodoo is performing a full afterburner take off. Note ...
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How does control system design ensure correct elevator position with the steering system unlocked? [closed]
I’m having some trouble answering the following problem encountered in one of the worksheets for aviation students:
The plane shown in the picture stands on the runway. The pilot, while getting off, ...
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what is considered a good pedal performance in a fighter?
What is considered a good performance in designing the directional control law in a fighter? Is it acceptable to have some roll when using a pedal? For example, is it acceptable to have 40 degrees ...
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Does the pilot always need to use stick to compensate roll caused by pedal?
When the pilot uses pedal in a fighter like F-18, does the aircraft roll? If so, is it the pilot's job to compensate this roll or the control system compensates it automatically? In other words, is it ...
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Control surface deflection during takeoff
What is a reasonable (or typical) control surface deflections required for takeoff?
I would like to know two ball park values if possible
elevator deflection for conventional transport aircraft
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Why are there no high wing Canard airplanes?
Just had a thought about canard airplanes while looking at the Tu-144 that features a canard surface on the top of its fuselage.
Are there any high-wing aircraft with a top or bottom mounted canard? ...
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How are control surface problems in wings having high bending dealt with?
In some aircraft which have large wing deflection due to bending, do ailerons or flaps not get stuck or bent themselves? In the case where hinging axis is also bent how do ailerons operate?
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How exactly do the Beechcraft 1900's stabilons work?
The Beechcraft 1900, in addition to the usual wings and vertical and horizontal stabilizers, and the extra vertical tail surfaces added for improved directional stability, has a pair of horizontal ...
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What is the maximum control surfaces deflection on a Cessna 210N?
Does someone know how far the control surfaces (rudder, ailerons, elevator and nose gear) can deflect in a Cessna 210N? I've been searching Google and the POH for hours now and can't find it.
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Why would control-surface balance horns cause problems at transonic speeds?
On many aircraft, control surfaces such as elevators, ailerons, rudders, etc., have "horns" which extend forwards of the surface's hingeline, wrapping around the tip of the wing or ...
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Do the different spoilers on an A321 extend by different amounts? [duplicate]
I recently flew with an A321 and watched the left wing while the pilot tested the control surfaces before lift off. I noticed that one of the spoilers angled upwards much less than all others. In the ...
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Why are the grid fins on Starship pointy and sharp?
The grid fins on Starship are serrated, why? Does it help in transonic maneuvers?
Source: Starbase Factory Tour with Elon Musk [Part 1], YouTube, at 30:28
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Angle of Attack influence on Adverse Yaw
we are analyzing an aircraft's lateral-directional control characteristics with self-made code. We have observed that the aileron's influence on the body axis yaw moment is quite sensitive to the ...
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What are the degree markers on the tail of this MD-10 for? [duplicate]
I took this picture of of Orbis's McDonnell Douglas MD-10-30. Tail: N330AU.
What purpose do the 0 and 2 degree markers serve?
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Replacing cyclical control with tilt-able rotor using EV motors and servos
I understand the traditional reasons for cyclical control (with swash plates) on helicopters; ie, avoid gyro effect, shaft can be fixed. However, if the power plant was a modern EV motor, and ...
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What should a pilot do if none of the control surfaces are responding? [closed]
What would a pilot do if none of the control surfaces are responding?
For example, a pilot flies a medium-sized plane and to make the situation a bit less hectic, they're the only one onboard. Then ...
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What suits best for lateral controllability at high Angle of Attacks- a vortex generator or wing slots?
At high angle of attacks, the prominent problem is the separation of airflow. And if this airflow separation is near ailerons, we lose lateral controllability.
And the solution is making the flow ...
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Why does the Cessna 208 Amphibian have extra tail surfaces?
Mark Harkin, CC BY 2.0, via Wikimedia Commons
I've seen extra tail surfaces that look like additional vertical stabilizers on the C208 Amphibian. Why is there a need for this? I can't imagine that ...
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Under what circumstances does the F-16 and possibly similar fighters deploy leading edge slats?
What does the F-16 (perhaps other fighters as well) use to decide when to deploy leading edge flaps? I would assume angle of attack, airspeed, stick deflection, or some combination of the three, are ...
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Do the stabilators on the F/A-18 also have a roll function similar to the F-22?
I'm curious about the F/A-18C. I know it has ailerons, but they seem too small to be greatly effective at low speeds. Do the stabilators have a roll function as well? If so, is there a speed at which ...
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Can flaps be used to perform rotation and flare?
TL; DR using flaps to directly control sink/climb rate near ground = simpler and faster response = easy to fly airplane?
Rotating is the pitch up during takeoff that causes the aircraft to leave the ...
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What are typical control surface deflection "rate" limits for transport airplanes?
I was wondering if anyone knows what are some typical control surface/actuator deflection "rate" limits for transport airplanes (i.e. aileron/elevator/rudder deflection rates)? I haven't ...
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What does gravity compensation do in flight control?
In flight control designs for lateral directional movement, there is a block named "gravity compensation". This block changes yaw rate measurement from "$r$" to "$r-g/Vcos(\...
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Why do the ailerons of this flying wing work oppositely compared to those of an airplane?
I made this simple wing glider and put some ailerons on it. I thought that the ailerons in this glider would work the same way it works on airplanes, wherein the roll will be in the direction of the ...
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How do tailless aircraft yaw? [duplicate]
I was doing research on control surfaces present on an aircraft and I noticed that some aircraft like the B2 Spirit does not have a vertical tail stabilizer and therefore no rudder either.
How do ...
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In missiles, what actuators are used for the control surfaces?
In a normal airplane, hydraulics or even cable-pulled systems are used to power the control surfaces. In a missile, that seems infeasible. What device is used to move the control surfaces, and where ...
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What, if any, would be the most correct term for the aerodynamic flight control surfaces of SpaceX's Starship?
SpaceX's Starship uses a unique flight control scheme during descent that I have not seen anywhere except with skydivers: it falls straight down belly-first using four aerodynamic control surfaces at ...
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What is the benefit of a horn control surface?
Like the one above. Is it just so that you can hinge closer to the leading edge of the aileron or control surface? Why did the designers of the ATR-72 elect to use this feature?
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How do fighter jets stop pitching motion after a elevator deflection?
I'm working on a flight simulator , In which the jet has only ailerons , rudder , and two elvators at the back . When I nose up my aircraft via elevator deflection , it just keeps pitching up ( even ...
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What control surfaces do I need to move to do a roll in a model aircraft?
Figured that this was the better site to ask than drone SE, but if I'm wrong just let me know.
I'm making a spitfire model and was just wondering how do I do a roll? I have elevator, rudder, and two ...
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On large aircraft, why do flaperons not run the full length?
This is a 777 flaperon. It looks rather tiny, compared to the flap.
There have been air disasters where the airplane rolled uncontrollably for one reason or the other. It seems to me that a larger ...
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What is the name of Control equipment? [closed]
I wanted to know the name of equipment that controls the control surfaces of an aircraft by taking commands from the pilot through it's hotas stick. The aircraft could be a combat 50's or 60's a/c, so ...
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Why does the Eurofighter Typhoon have a long arm canard versus the close coupled canard of the Dassault's Rafale or the JAS-39 Gripen?
The Rafale and the Gripen are quite similar but the Eurofighter Typhoon has the canards far forward. I've been told that this was due to the shape of the air intake.
Apparently the Typhoon's air ...
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How do linear actuators for flight controls work in fighter jets?
I've built some rc planes and know that in order to control an aileron in a rc plane, that you need a servo, a control horn(sticking out of the aileron), and a pushrod. However, I was wondering how ...
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Is there any non-experimental way to obtain CL, CD, and CM as a function of the angle of attack and the control surface deflection angle?
I am working on a flight simulator for control algorithm testing. The issue I am facing is to come up with a relationship between CL/CD/CM and the angle of attack ($\alpha$) and the control surface ...
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Why does the zeppelin NT tail use 3 fins?
I don't if I use the correct vocabulary. By "fin", I mean the control surface at the tail of the airship. As a control surface, it contains a moving part.
As airship used to have at least 4 fins at ...
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In an F-18, how do rudders deflect during cross winds and gusts? Can rudders be deflected by different angles?
Deflection of rudders can balance moment about the centre of gravity. I have thought of non-symmetric deflection of rudders so that net sideward force is create to balance the moment about the center ...
