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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3
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1answer
71 views

Would a wingtip stall still be bad if there was no aileron there?

If there was no aileron on the wing tip, would a tip stall still be bad compared to a root stall?
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Leading edge or trailing edge stall?

As I wrote last week, I'm doing a Benedek 10355 airfoil performance report. At this point of the work I am analyzing the stall of the profile at a fixed Reynolds number. The Benedek 10355 airfoil has ...
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4answers
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What's the relationship between AOA and airspeed?

We know that any aircraft will stall at its stall speed (for a specific weight, CG position, etc.) but also, that the same airplane will always stall at the same angle of attack. I´ve read that IAS is ...
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In symmetrical airfoils is the stall angle the same for negative AOAs as for positive ones? [duplicate]

In symmetrical airfoils is the stall angle the same for negative Gs as for positive ones? Let say the stall angle is 17 degrees AOA. Is it the same if you push the nose down?
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What does the autopilot do if activated in a stall condition?

I was thinking about Air France 447 recently and had a wonder: What would happen if the pilots had re-engaged the autopilot and stopped all stick input? (If that's even possible in a stall condition). ...
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Why does my wind tunnel experiment give two different stall angles of attack?

When I increase the angle of attack from 0 to 20 the stall begins at 18 deg. When I decrease the angle of attack from 20 to 0 the stall ends at 13 deg. Why the difference and what value (13 or 18 deg) ...
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7answers
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Why angle of attack is always shown against the relative wind parallel to horizon?

I have a question about Stall, which I have difficulty to understand. According to the theory, stall happens when : 1- Speed is slow then a certain limit. 2- Angle of attack is greater than a ...
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2answers
181 views

Why is the critical angle of attack lower in ground effect?

Why is the stalling angle of attack lower in ground effect? Does ground effect more increase pressure on lower side of wing (cushion effect) or more decrease pressure on upper side, or both? So which ...
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1answer
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Is it possible to increase available take-off distance for a seaplane by turning?

In the video below an A5 had an accident after takeoff. The final cause of the accident seems to be a sharp increase of AOA above stall. Do sea planes have an ...
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3answers
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What is the impact of camber on CLmax?

I was reading Aerodynamics for Engineering Students by Houghton and saw the following graph: A lot of other sources say that increasing camber increases CLmax, like the graph below. I am a little ...
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6answers
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Is it practical to intentionally stall an aircraft to execute a fast, controlled descent?

An MD-11 had an onboard fire, but had to request more flying distance at least partly to execute a safe descent (and to dump fuel). It ended in tragedy. In another accident, an A330 descended 30,000 ...
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2answers
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Should I use rudder to recover from power-on stalls?

I was executing a power-on stall, and upon stalling the nose dropped and the plane rolled hard right. I promptly applied left rudder and released yoke backpressure to recover, and the plane recovered ...
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Helicopter retreating blade stall: Increasing the fwd speed decreases the tip speed on retreating side and angle of attack. So why limit on V_n.e?

On Retreating side: Speed of wind over blade tip = blade rotation speed - forward speed. So, with an increase in forward speed, the speed of the wind over tip is getting reduced. In airflow diagram, ...
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3answers
446 views

Do adding high thrust in plane prevents it from stalling?

I am convinced that fighter jets (every flying object) do stall. So from quora, Why don't fighter jets stall? But most of the fighters have thrust:Weight ratio > 1 which means that they are not ...
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1answer
252 views

How to find the static stall angle of attack for a given airfoil at given Re?

For vertical axis wind turbines applications I'm wondering how one would find the static stall angle of an airfoil at a given Reynold number? Is it just the critical angle of attach (AoA) where ...
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Are larger airplanes more likely to stall?

Stalls happen when the boundary layer on top of a wing slows so much that it essentially becomes part of the airfoil. My question is, as the wings on larger aircraft present a longer flow path for ...
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Is a “stalled” aircraft free-falling?

If I was in an elevator in a sky-scraper and the cable broke, I would free fall and feel weightless until hitting the ground. When I cause a stall on an airplane (power-ff) and the wings stop ...
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What are the effects of separation at hypersonic rarefied flows?

Shock wave causes an adverse pressure gradient which causes an airfoil to stall. Also because gas density is much lower boundary layer becomes laminar and unable to prevent separation. Correct me if ...
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Would it be frowned upon that with a uncommanded nose up, the pilots just do a full loop?

So what I’m asking is that if a uncommanded nose pitch up happened and was so bad that it reached a pitch angle of 50 degrees, the pilots were unable to stop the pitch up by applying the control ...
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2answers
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Why does a higher load factor increase stall speed?

I think that’s self explanatory, why does load factor (G) affect stall speed? Why does load factor result reaching the critical angle of attack at higher airspeed?
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1answer
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What is the stall AoA for the space shuttle?

Once flying as (fast) glider in order to land, what was the angle of attack it would have stalled? I'm really interested in the angle of attack for such wings and not the speed.
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What plane has the widest range in speed in which it can operate? [duplicate]

What propellor plane, other than planes with vertical takeoff capability, has the largest gap in speed between its slowest stall speed and its maximum airspeed? I am looking for a plane with a short ...
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What is the stall speed of the Antonov An-225?

Under certain circumstances - maximum gross weight, unaccelerated 1G flight, clean configuration (landing gear up and flaps)? Indicated airspeed (KIAS) of course.
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4answers
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When approaching a stall, is the first priority to apply power or lower nose?

I’ve always wondered. And I’d assume it’s the same regardless of aircraft? But when approaching a stall would the main priority be adding more power? I ask because what if a crew was on final for ...
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1answer
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How is d(Cl)/d(alpha)@stall and Cl increment to stall defined in Xrotor?

I hope there are some people around here with some experience in Xrotor than me. (Xrotor is:"XROTOR is an interactive program for the design and analysis of ducted and free-tip propellers and ...
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4answers
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Would the front rudder of the Wright brothers really have helped in recovering the glider from a stall?

I have found a paragraph in the 1904 British patent of the Wright brothers (see the citation below) and it seems, from what they explain, that the two inventors believed the front rudder could have ...
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Has a commercial jet airliner ever stalled on takeoff / at low-altitude?

In general aviation, a common reason for fatalities is low altitude stalls on takeoff or practising go-arounds. Has there ever been an incident where a commercial jet airliner stalled on takeoff / ...
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Can anyone explain the reflex wings used in powered paragliding?

There are some paramotoring wings presumably designed for higher speeds. The method is to allow a portion of the wing near trailing edge to flutter in high speed, rendering it unaccountable for ...
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2answers
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Why do light aircraft stall their wings to land? [closed]

What's the advantage compared to large commercial aircraft that don't stall their wings on landing?
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250 views

Which type of fan is better for wind tunnel testing?

I would like to build a small wind tunnel to test a miniaturized wing/airplane. I have two options, using axial blower (picture 1) or using centrifugal blower (picture 2). The first will be the wind ...
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1answer
393 views

What Is a “Fully Stalled” takeoff?

Reading this article (on the Boeing 737 MAX saga; irrelevant), I found the following excerpt: Boeing ultimately accepted Davies recommendation and, we understand, halted production of the 707 for ...
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1answer
237 views

What is stall speed exactly?

I used to simply think It was the speed where any attempt to pitch up to maintain an equilibrium between lift and weight would result in flow separation, But Wikipedia says; But I noticed in a Sim I ...
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1answer
78 views

Partial panel power on stall under the hood

What do you use for control and performance instruments while demonstrating power on stall under the hood with attitude and heading indicator covered (No vacuum instruments in 6 packs ) ?
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1answer
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Why does the stall angle decrease as camber increases?

I have a rough idea about why $C_{{l}_{max}}$ increases with increase in camber. But I can't explain why the stall angle decreases simultaneously.
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2answers
697 views

Is it okay to purposely stall a small single-engine aircraft just before touch down to get a good flare?

I'm still learning ground theory and have only flown in simulators (P3D v3 Academic). For a long time, I've been trying to properly flare single engine aircraft but have mostly failed. I even watched ...
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1answer
377 views

Why doesn't Concorde stall when passing Mach 1, where a normal airliner does?

As Jay Carr asked: What is a high speed stall?, Jan Hudec explained: A difference from normal stall is that after supersonic flow separation the lift remains proportional to angle of attack and so ...
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1answer
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Can aircraft stall at low speed during final landing?

Is it possible for an aircraft to stall when it turns multiple times before landing and its airspeed is below 200mph? And if it does, is there any way to recover at such low height and speed? I always ...
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1answer
91 views

What are the margins used to avoid a stall while slipping near the ground?

Similar questions have been asked before, but in life-and-death questions like this, I want to be certain. This question is about airplane behavior close to the ground in normal and/or near slow ...
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1answer
199 views

Does the wing always have an adverse pressure gradient along the chord?

I know that there is an adverse pressure gradient on the upper surface of the wing, which leads to boundary layer separation. Is there any condition under which there is no such adverse pressure ...
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1answer
159 views

How to design a near vertical take off airplane?

How to design a near vertical take off airplane, conceptually? Say I have an airplane, similar to a Zenith 701. Say that it has a stall speed of 50 mph and a wing area of 60 sq ft, and it weighs ...
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1answer
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Does a decreasing shape factor correspond to greater or reduced probability of separation?

The shape factor ($H=\frac{\delta^*}{\theta}$) is the ratio of displacement thickness, a measure of the thickness of the boundary layer, to the momentum thickness, a measure of the shear stress. I ...
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5answers
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Why does airflow separate from the wing during stall?

What causes the airflow separation from the airplane wing, that triggers a stall? To be more precise, what is the detailed explanation of the physics for why flow separation occurs at certain speeds ...
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Consequences of stalling while sideslipping in a glider? [duplicate]

In a glider, sometimes it's useful to do a side slip with crossed controls. However, when that happens, the pitot tube angle is out of line and the ASI goes to zero, therefore losing any indication of ...
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4answers
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What is the regular stall speed of an F-16 flying in a straight-and-level path?

I want to know what is the minimum speed that an F-16 can fly at without stalling. I have searched the web, but found no exact information answering my question. Most of them say that it depends on ...
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1answer
282 views

If a beginner paraglider / paramotor wing fully stalls, how much vertical distance is needed for recovery?

In paramotoring, a beginner wing is a wing with A, B, C, D and F (brake) lines. When a full stall is induced, a pilot may fall a long, long ways before the wing will recover, and most will need to ...
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1answer
411 views

Why does the effective alpha/CL increase at wingtip of swept wing?

If anybody could explain this in an intuitive way I'd really appreciate it. I haven't been able to find a clear answer on this. I understand that the increase in effective AoA/CL and the spanwise flow ...
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4answers
859 views

Why does indicated stall speed change?

Aviation confusing me... I’ve read that stall speed doesn’t change (IAS) no matter what altitude you’re flying - of course under specific conditions ISA, 1G level flight, no wind, gross weight etc. ...
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2answers
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What makes the Antonov An-2 have no stall speed?

The Antonov An-2 is notable for being able to fly at a very low speed. However, what confuses me is that it has no stall speed: The An-2 has no stall speed, a fact which is quoted in the operating ...
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2answers
255 views

What will be the performance penalties of increasing the wing area of a delta winged aircraft to obtain a lower approach speed?

Delta winged aircraft such as the Dassault Mirage III have an approach speed of 170 knots as specified by the manufacturer. The Mirage F1 was designed to have a lower take off and landing speed than ...
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3answers
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How can I fix the stalling of an RC plane after the addition of floats?

I'm modifying a RC plane into a bi-plane with floats and it keeps stalling. I don't have a bigger battery or better motor to add so how do I fix this? This is the biggest challenge I've ever faced.