# Questions tagged [angle-of-attack]

Usually refers to the angle between the oncoming air and the wing.

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### Pitch of a glider with altitude

I'm designing a high-altitude glider. Just to clarify a few points before my question: The glider will weigh close to 200 grams. It will be using the A18 airfoil. The glider is dropped from 80,000 ...
156 views

### Conundrum about designing a glider relating to coefficient of lift

I'm designing a high-altitude glider. Just to clarify a few points before my question: The glider will weigh close to 200 grams. It will be using the A18 airfoil. The glider is dropped from 80,000 ...
127 views

### How to maximize L/D ratio by design in a high altitude glider? [closed]

EDIT: Some initial confusion with TAS and IAS confused me, I now understand this better, thanks for everyone who helped. I'm designing a high-altitude glider, and I'm wondering how the angle of attack ...
1 vote
1k views

### Do wingtip vortices cause a decrease in the lift component of aerodynamic force, and do planes need to pull more AoA to compensate?

So, from what I know about wingtip vortices, they shift the angle of the relative airflow to where the effective angle of attack of the airfoil is lowered. Since the aerodynamic force is always ...
102 views

### How does a glider in steady descent glide with negative AoA? [closed]

EDIT: I now understand relative wind is parallel to the travel of the glider. Ignorance was the basis of my earlier confusion. I looked at some toy and commercial gliders and all of their wings were ...
1 vote
75 views

### Constant Speed Propeller and Angle of Attack

Question regarding the AoA (Angle of Attack) on a Constant speed. The CSU (governor) sets the blade angle based on the desired RPM, and the flyweights keep it from speeding up or slowing down using ...
117 views

### Why does the wing drop prior to a spin?

In the process of understanding the aerodynamics of spins, I'm having a hard time understanding why one wing drops. I understand that the for spins to occur, a stall + a yaw must occur. I also ...
218 views

### Why Critical Angle of attack doesn't change with an increase of IAS/TAS?

I am trying to understand this topic that is not letting me sleep. I am a private pilot and I am studying for the CPL, if someone could give me a simple explanation of this I would be very grateful. ...
1 vote
157 views

### Critical angle of attack at high altitude

I remember hearing somewhere that at very high altitudes, the critical angle of attack for a given airfoil can decrease a bit. Is there any credence to this idea? Thank you
105 views

### 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 ...
274 views

### 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 ...
265 views

### 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 ...
1 vote
1k views

### 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 ...
4k views

### 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?
655 views

### 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 ...
212 views

### 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,...
820 views

### 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 ...
15k views

### 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 ...
821 views

### 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 ...
7k views

### 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?
2k views

### 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 ...
473 views

### 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?
656 views

### 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 ...
1 vote
470 views

### 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 ...
728 views

### 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 ...
727 views

### 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: <...
2k views

### 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 ...
658 views

### 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 ...
39k views

### 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?
619 views

### 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 ...
1k views

### 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 ...
2k views

### 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 ...
566 views

### 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 ...
359 views

### 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 ...
314 views

### 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 ...
2k views

### 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 ...
658 views

### 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 ...
1 vote
144 views

### 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 ...
4k views

### 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 ...
1 vote
329 views

### 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 ...
1k views

### 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 ...
2k views

### 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 ...
3k views

### 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 ...
6k views

### 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
917 views

### 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 ...
1 vote
265 views

### 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 ...
1 vote
339 views

### 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 ...
2k views

### 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-...
1 vote