# Questions tagged [stall]

A stall is an aerodynamic condition wherein the angle of attack of a wing increases beyond the "critical angle of attack", causing the wing to cease generating lift.

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### Will a plane 'shake' when it stalls?

I haven't been able to confirm this, but does a plane shake when it stalls? If so, why? I was able to find some info on this, but from a non-confirmed source. As the plane shakes and rattles, it's a ...
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### Is washout a twist up at the root or a twist down at the tip of the wing?

Does washout/in take place at the root of the wing or the tip? And is the twist distributed evenly along the wing, or is it only twisted for a portion and level for the rest, specifically in ...
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### Why will the pressure distribution of a swept wing promote stall?

Here it explains how the bound vortex will change the lift distribution of a wing. What is meant by the lift distribution changing is that there is less lift at the tip, meaning the pressure ...
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### A question on stalling and flat spin - in gliders

Very short version: Do gliders do stalls, and flat spins, as aerobatic tricks (as do say aerobatic biplanes). -- As I understand it, with an aerobatic plane, a pilot can and does, for "fun" ...
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### Whats the derivation of a low speed ratio for stall warning?

I've seen an equation related to stall and angle of attack in a few places like this patent that goes more or less: $$\frac{CAS_{alert}}{CAS_{current}} = \sqrt{\frac{C_{L,current}}{C_{L,alert}}}$$ ...
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### Does more lift cause a plane to stall at a lower airspeed?

Does more lift cause a wing to stall later? (By more lift I mean a bigger wing) I was looking and saw this question, but the answers didn’t really address why more lift will help a plane not stall. ...
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### Can partial flow separation make the effects of Reynolds number on stall more significant?

While discussing this stall differences with altitude question with a skydiving canopy designer, I told him that most people seemed to think Reynolds would not be significant at these altitudes. His ...
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### 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 ...
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### Comparing a Flight In Turbulent Conditions At Va And Vb

First, let's cover definitions for both airspeeds: Turbulence penetration airspeed (Vb) is the design speed for maximum gust intensity (i.e. the intersection between the 66 fps gust line and the ...
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### How do thicker airfoils give better stall characteristics?

Why do thicker airfoils have better stall characteristics? They make more lift, but I don’t see any reason for them to have better stall characteristics. Also, I heard a rounded airfoil nose will help ...
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### 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 ...
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### Is this the correct functioning of a reed type sensor in a stall warning system?

I understand that this type of system works based on suction. According to what I read, at angles close to the critical angle of attack, the pressure near the leading edge is very low, this generates ...
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### Is it okay to do power off stalls in the clean configuration for a check ride?

I’ve been renting a plane for a while and the owner has asked due to a safety concern that we don’t use flaps in our stalls or slow flight. The airplane flying handbook and the ACS call for these to ...
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### 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. ...
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### What is the mathematical relationship between mass and speed for constant thrust in level fight?

Imagine that we have a wing with constant thrust in level flight. Then imagine that we add mass to that wing. In order to maintain level flight, I would expect that the angle of attack would need to ...
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### Use twist to improve stall characteristics in ideal distribution of lift coefficient

Is practical use twist (geometric or multiple airfoils to improve stall characteristics) when it has lift coefficient distribution ideal or near due to wing plataform? I am analyzing a "Schuemann&...
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### Trailing edge tapered and leading edge straight

It is true that a wing with a straight leading edge and a tapered trailing edge has good stall characteristics?. That is, we can assure that when it enters stall, it will first be at the root and then ...
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### Effect of wing flexible in stall

How true is it that the deflection (due to large aspect ratio, flexible wing ) of a wing has a certain effect on the stall characteristics? I read about this in the case of large wingspan gliders. ...
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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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### Why does stall warning system require 4 minutes of AC power on the 737NG?

Is it related to the Stall Management Yaw Damper (SMYD) computers starting? But the number 1 stall test is working with no need for waiting. Please provide sources, if available.
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### How should you deal with passenger throttle interference just after take-off?

I took a passenger on a flight recently in a C42, in which the throttle is placed between the legs. Shortly after take-off (I'm talking 100ft in the air at full throttle), the passenger tucked his ...
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### Confusion about center-of-lift vs center-of-gravity [duplicate]

As usually depicted, in a small aircraft (maybe larger commercial ones too), the lift due to the main wing (excluding the elevator) is depicted as on average aft of the center of gravity, with the ...
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### Is the interpretation of "54 knots CAS at the aircraft’s maximum certificated takeoff weight and most critical center of gravity" subjective?

The newly proposed MOSAIC regulations state in § 61.316 (1) A maximum stalling speed or minimum steady flight speed without the use of lift-enhancing devices (V S1 ) of not more than 45 knots CAS, ...
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### Are there any stall warning apps available?

Recently I was flying a 500ft circuit, when in the downwind leg I felt a buffeting, when I looked at my ASI, to my horror, I was at stall speed. I recovered without incident, (recover might be an ...
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### What are the advantages and disadvantages of a low stall angle?

One advantage I can think of is when we increase the wing's angle of incidence to decrease fuselage drag and increase takeoff lift, but would higher stalling angles always be better in terms of flight ...
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### Other than training and some landings, do pilots ever stall on purpose?

Other than in training/practice and some landings, do pilots ever intentionally stall?
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A response to a previous question indicated, “In a helicopter, aft cyclic (“pitching up” in a plane) will only serve to make the helicopter climb and slow down until it reaches equilibrium in the new ...
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### Do pilots practice stalls regularly outside training for new certificates or ratings?

I know that stall practice in real aircraft is part of PPL training, and that airline pilots training for type ratings practice stalls in simulators. After obtaining a certificate/type rating, do ...
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### Stall on low airspeed with high power on right-turning propeller

Q: The pilot of an aeroplane with a single engine and right-turning propeller (clockwise from the pilot’s viewpoint) decides to go around. The pilot raises the nose too much as the power increases and ...
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### Why would a ram air parachute need less brake input to stall at a higher altitude?

I have some anecdotal evidence that a ram air sport parachute requires less toggle input to stall at higher altitudes. A pilot needed one wrap of the brake lines around the hands to quickly, ...
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### Why is the A330/A340's alpha-floor protection disabled above mach 0.53?

One of the A330/A340's several means of flight-envelope protection is something called "alpha floor" protection. In essence, if the aircraft's angle of attack is excessively high, TOGA ...
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### Can I identify wingtip stall by looking at the lift distribution?

I'm projecting a wing in XFLR5. The lift at the tip of the wing looks like it's dropping very quickly close to the stall angle, so I think there may be wingtip stall, however, is there any way I can ...
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### Effect of leading edge contamination wing performance

When a wing accumulates irregularities such as insects or dirt on the leading edge, its performance decreases. There are two main effects of this which are explained in https://aviation.stackexchange....
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### Literature request for effect of Aspect Ratio and Wing Sweep on critical angle of attack?

So I'm trying to find academic literature detailing how both aspect ratio and taper ratio affect the critical angle attack of an aerofoil - namely for a v. low AR wing (AR<1), and high sweep (~75 ...
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### How would I go about finding stall/loiter speed data?

I have a list of 6 fixed-wing and 2 tilt-rotor aircraft that I require the stall and loiter speeds for, however I have great trouble finding these. Is there a book or website that has an extensive ...
1 vote
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### Is it normal to fly or glide only one mile per hour above stall speed?

At one point, Through Gates of Splendor describes Nate Saint gliding in his Piper PA-14 Family Cruiser at 45 mph; the plane's stall speed is 44 mph. Earlier in the book, he flew at 45 mph. Is it ...
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### How is a stall different from a spin?

Is a spin a by-product of a stall? So if a airplane stalls is a spin guaranted sooner or later?
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### Sudden "nose-down" event during a normal flight in normal weather conditions

I had a flight scheduled from WAW to KIV on LOT airlines. The boarding pass told they changed the aircraft to a 737 MAX. When I saw that I've immediately remembered that whole MCAS story from 2018. ...
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### Under what conditions do airplanes stall? [duplicate]

I've seen somewhat conflicting information on when planes stall. I've seen references to "stall speed," apparently a speed below which the airplane will stall, but stalling also seems to be ...
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### Why do airplanes usually pitch nose-down in a stall?

Why do airplanes usually pitch nose-down in a fully-developed stall? I've seen this seemingly-simple question discussed on other aviation forums, but there doesn't seem to be a single agreed-upon ...
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### Is it possible to avoid vomiting while practicing stall?

I found that even after 30 flying hours in a Cessna, my body still cannot tolerate practising stall, thus throwing up and dizziness follow up after the sorties. Is there any way I could prevent that?
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### How deliberately stall fixed wing reduce drag if stall decrease static pressue? [closed]

In this VIDEO at 5:40 we can see how stall decrease pressure at upper wing surface. If stall/flow separation reduce static pressure how in this VIDEO they reduce drag when stalling the wing? Here is ...
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### Could a F-22's exhaust stall a highjacked Boeing 767's turbofan(s) and force it to land?

Would it be possible to use a F-22's exhaust to intentionally stall a hijacked Boeing 767's turbofan engines in order to force it to land instead of shooting it down? The idea being that stalling one ...
1 vote
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### Does Indicated Stall speed increase with altitude (Coffin Corner)?

It is my understanding that Indicated Stall speed is mostly constant with altitude, the one that increases is True Stall Speed. Given that PFD show speed as IAS, how come the yellow speed range ...
1 vote
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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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### Is a plane stalled during landing rollout?

IMAGE SOURCE: https://pilotinstitute.com/wp-content/uploads/2022/01/Parts-of-a-Wing.jpg As the lift dumpers are extended on landing they cause the air to move away from the wing. Also as the flaps are ...
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### What are some features of a wing, which effects its lift coefficient other than its sectional view? [duplicate]

What geometrical features of a lifting surface apart from which airfoil it has, I mean the ones visible from the top and front view of a wing (for ex: its span, AR, sweep, dihedral etc.) effects its ...
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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 ...