Questions tagged [angle-of-attack]
Usually refers to the angle between the oncoming air and the wing.
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Incidence angle in Sailplane
I am determining the shape of the fuselage of a sailplane and I found something that gives me a little conflict, and that is that in most sailplanes it has an inclined tip, I read that this helps ...
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What is the maximum speed at which thrust vectoring can be used? Thrust Vectoring on the SR-71
The SR-71 is limited to a 45 degree bank turn at speeds in between mach 2.85 to ~3.2. This means the blackbird would take almost 5 1/2 minutes to make a 180 degree turn at mach 3. Would it be possible ...
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Does AOA become 0 after the aircraft flies in a particular attitude for sometime as the relative airflow has changed and how does it affect Stall AOA?
As AOA is the angle between relative airflow and Chord Line. Then after you increase the angle of attack and fly at that angle of attack for some amount of time and the relative airflow changes ...
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What happens to the pressure differential of airflow under and over the wing as the critical angle of attack is reached?
I've been doing a research project for mathematics which involves calculating the relationship between lift and angle of attack. While this may seem pretty easy, it's not for a 12th-grade student like ...
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Why do most light aircraft not have AoA indicators?
Why is an angle of attack indicator not commonly included on small airplanes? Is it too expensive?
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Why would the tip of a propeller stall if geometric pitch was the same throughout the length of the propeller?
I can't seem to understand this sentence from the FAA PHAK about why propellers are "twisted."
"If the blades had the same geometric pitch throughout their lengths, at cruise speed the ...
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Why are there no protection symbols (=) for high AOA protection on Airbus aircraft?
Green protection symbols (=) are displayed for many protections on Airbus aircraft, such as for bank, pitch, and high speed protection. However, there is no such symbol for high AOA protection. Rather,...
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Why does elevator trim hold a given airspeed? [duplicate]
I'm trying to understand a principle described in the book Stick and Rudder by Wolfgang Langewiesche between angle of attack and airspeed in relation to the elevator trim. He states that as angle of ...
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Is there a simple relationship between angle of attack and lift coefficient?
Is there an equation relating AoA to lift coefficient?
I have been searching for a while: there are plenty of discussions about the relation between AoA and Lift, but few of them give an equation ...
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Is it possible to get into a spin situation while coordinated?
Is there any possibility of spinning while coordinated? Of course, any CFI would tell you no, but I wonder if the the following situation could result in a spin while coordinated:
Slow level flight ...
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Why does the stagnation point on airfoil move with the angle of attack?
What is the physical explanation for the reason the stagnation point is where it is? And, why does it move further down the lower side of the airfoil with an increase in angle of attack?
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Lateral Aerodynamic Derivatives from Digital DATCOM
As far as I know the Digital DATCOM can be used to estimate longitudinal aerodynamics by varying the angle of attack. Does it have the capability to vary sideslip angle for lateral analysis? and How? ...
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Which wing stalls first in a level coordinated turn?
I was told that in a level coordinated turn the inside wing stalls first because it has a higher angle of attack (AoA).
Now, I have always thought that in a level coordinated turn, the wings must have ...
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Did the F-16 have an AoA limiter since the very first variant?
Did the F-16 have an AoA limiter since the very first variant or was it added later?
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Where to find out the correct values of AOA of Boeing 737 during different phases of flight?
We can say that practically there are minor differences in AOA for each flight (in the same range of weight). But is there any document that states what flight angle is recommended for each of the ...
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How does camber affect on critical aoa?
i am pretty clear about why a higher camber would increase Clmax, but critical aoa.
one of the resources i read the graphic shows a greater chamber near the leading edge will increase Cl at different ...
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Projected Area & AoA - Projected area of the wing is variable (as projected on to a surface that is perpendicular to the relative wind)
Does Wing Area vary with angle ot attack?
Edit: why we don't recognize that the projected area of the wing as variable (as projected on to a surface that is perpendicular to the relative wind)
Per the ...
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How to choose an attack angle?
I'm writing a little piece of code for preliminary design that can calculate the ideal wing area for a given load, cruise speed and aspect ratio or span. It seemingly works well on the A380 data:
<...
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Why do smaller RC helicopters have visible twist in their rotors, and slightly bigger ones do not?
Smaller, cheap, RC helicopters generally have very pronounced twist in their blades, and also vary their chord - slightly larger, slightly more expensive RC helicopters have no visible twist or chord ...
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Does a wing produce an appreciable amount of lift during the takeoff roll prior to rotation?
I was hoping for some insight on this, perhaps also from pilots who have used AOA indicators. This because I assume that an AOA indicator is the only means to get at least an idea of how much lift is ...
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Why does the B-52 take off without rotating?
In the answer to this question it is noted that the B-52 takes off without rotating and climbs out in a nose-down attitude. Why was it designed this way?
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Variable-pitch propeller blade design (AOA)
For a variable pitch propeller where the angle of attack can be adjusted during flight, are the individual blades similar in design to standard propellers, with a low angle of attack at the edge of ...
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Will the autopilot raise the AoA above the critical AoA to maintain altitude?
NOTE: This question is regarding commercial airliners (eg: Boeing 737, Airbus A320, etc.. This is for any given configuration of the aircraft)
Will the autopilot raise the AoA above the critical AoA ...
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Are there wool threads for displaying angle of attack?
Like there is a wool thread on a glider's canopy for showing relative wind on yaw axis. Are there or have there been a wool thread as a long term mean of showing angle of attack?
For instance placed ...
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Why is this angle of attack sensor tab not symmetrical between the leading and trailing edges?
Here is an Angle of Attack (AoA) sensor I took from here. If you are interested to know the AoA detail, just click the link. You may see what is inside it. But not sure what airplane's AoA sensor it ...
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How does a synchro resolver converter work?
There are Synchro converters or transducers used on aircraft to measure angle of attack using 3 sinusoidal inputs. I could not understand where these 3 inputs come from and what angle information is ...
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Do critical angles of attack vary from plane to plane? Can a plane have higher or lower critical AoA than the other?
I have done a lot of research and I have found out that different planes have different climb angles. Some look like they are climbing at a higher rate than others. Why is this? Do some aircraft have ...
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Can induced drag be negative?
For an aircraft in straight and level flight, lift-induced drag is the horizontal component of the force perpendicular to the wing chord. Positively cambered aerofoils generate lift starting at small ...
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How the AOA, Pitch and FPA are changing during a flight maneuver
For a steady state flight, there is a equation that FPA + AOA = Pitch, but how these three variables are correlated during a flight maneuver like currently I am in a leveling flight and then I want to ...
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What is meant by the pointing vector and pointing vector magnitude in ECI?
In Siouris's Missile Guidance and Control Systems, it is stated that the angle of attack can be approximated in a 3DoF (degrees of freedom) simulation by the following equation:
I know that ECI ...
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Can a taildragger land tail first?
Inspired by this question...
How does a taildragger take off? Does it rotate?
I imagine if a taildragger has to land front wheels first it has a very limited range of Angle of Attack (if the pilot ...
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How the pitch of a blade must change along the length so that the blade does not stall?
I have to finish an assignment in the next couple of days. One of the questions asks to show how the pitch of the blade must change along the length so that the blade does not stall. I have no idea ...
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Do fighter jets experience angles of attack greater than stall when initiating a zoom climb?
I was just wondering that the fighter jets like F-16, F-35 and Rafale when they are doing a steady flight at a certain airspeed, try to rotate 90 degrees and aim to obtain a vertical motion, so does ...
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How to calculate drag of a flat rectangular surface at given area, air density, airspeed and angle of attack?
I'm a complete noob in aerodynamics, and I'm trying to calculate the drag of a rectangular flat area, given the air pressure / density, area, angle of attack and airspeed. I've read this question, but ...
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Why doesn't critical angle of attack increase with airspeed? [duplicate]
Critical angle of attack is related to the Coefficient of Lift, which is a function of Reynold's number. Reynold's number depends on the speed of the aircraft. So why doesn't the Critical Angle of ...
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Why do planes fly at a high angle of attack when flying slow?
I've noticed that when a plane does slow flight, the pilot increases the angle of attack (AOA). What is the purpose of this?
F-18 - Slow Pass
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Could the stick position be used as a Angle of Attack indicator?
True or False: The stick determines elevator position and elevator position determines angle of attack. When the critical angle of attack is exceeded, the wing stalls. So, given a design with enough ...
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Do redundant angle of attack and sideslip sensors use a voting mechanism, or do they display data directly?
In civil transport aircrafts (featured with dual/triple redundancy), how does airplane's Airflow angle (AoA/AoSS) sensor measurements read by the pilot? By using voter mechanism as used for airspeeds ...
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What are the relations between Angle of attack and Calibrated Airspeed?
I would like to estimate Angle of Attack using trigonometric relations i.e AoA = arctan (w/u) airspeed components (i.e u, v, w). When I am considering body 'x' velocity ('u' component), is it ...
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What are those devices sitting on top of instrument panel in this Baron?
On this Baron YT video:
what are the two devices sitting on top of the instruments panel, on both sides of the compass?
I though at first it is some kind of HUD (Head-...
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What happens to the high pressure below an airfoil when the angle of attack increases?
I recently came across this question in a principles of flight exam:
When the angle of attack of an airfoil increases
the high pressure below the airfoil increases, the induced drag increases
the ...
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Does the airspeed indicator measure speed inaccurately at different angles of attack?
A point of confusion for me has been this: Does the pitot tube measure the airspeed of the plane in the direction of its flight path, or does it measure the speed of the air parallel to the pitot tube ...
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How does the angle of attack vary in turns?
I read somewhere that when the aircraft banks to turn, its angle of attack increases.Since angle of attack is the angle between the relative wind and chord line, how does turning increase it? Is it ...
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Are we changing the angle of attack by changing the pitch of an aircraft?
For example:
if I pitch the airplane up, but also increase power and am able to maintain the same speed, then no, the AoA hasn’t changed, although it may have varied in the transition between one ...
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Is a wingtip vortex strongest at the critical angle of attack?
Generally, wingtip vortices increase in strength as the angle of attack increases. Is the critical angle of attack/Cl Max the peak strength, or do the vortices generally continue to increase in ...
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Does airspeed affect the critical angle of attack on an airfoil?
I understand that the critical angle of attack is mostly affected by the shape of the airfoil. However does the airspeed of the airfoil or the density of the air affect the critical angle of attack? ...
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Is there any practical benefit of the Boeing-787 to perform near vertical takeoff?
In a promotional video for the Paris 2015 airshow, this video was released promoting the new Boeing 787's near vertical takeoff capability. Whilst highly impressive, I was wondering if there is any ...
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In constant speed propeller, if i increase RPM lever from 2300 to 2500, will the Blade AOA decrease?
Assume I am flying straight and level with power setting 21 inches of MAP and 2300 RPM with TAS=100 kts, now I change my Prop lever only (MAP = no change & TAS = no change) from 2300 to 2500, ...
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With flight dynamic equations, how do I return to positive alpha if alpha is always negative with negative w?
I'm coding a flight dynamics simulation, but my simulation runs into a problem with negative angles of attack. Once alpha is negative, it is impossible to get back to a state where the plane is ...
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Does lift coefficient vary with the wind velocity for a given angle of attack?
I have this question in my mind. I have been trying to look for this in different books about aerodynamics and I couldn't find the answer. I know I could check the answer experimentally, if I had a ...
