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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0answers
91 views

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
124 views

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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6answers
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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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1answer
833 views

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
261 views

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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1answer
88 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
279 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
137 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
198 views

Is a stall warning Horn required to fly?

I need an answer in reference to 23.207. I looked there and couldn't say 100% if it was a yes or a no. Thank you for all your time. cheers
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1answer
56 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
179 views

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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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
243 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 ...
4
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1answer
369 views

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
83 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
137 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
136 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
78 views

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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3answers
539 views

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
123 views

If a beginner 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
243 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
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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
842 views

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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1answer
185 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.
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0answers
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Ground Speed On Approach [duplicate]

I'm not a pilot, just a bit of frequent flyer and moderate aviation enthusiast. I sometimes get on Flightaware and check on the flights I frequent and see the path that was taken and flight time. I ...
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3answers
163 views

How can I best prepare for my first lesson on stalls? [closed]

I am a flight student preparing to practice stalls and stall recovery in a Tecnam P-2002. I have already done spin recovery. On top of that, what preparation techniques have others found useful?
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481 views

How does MCAS compare to stall protection systems installed in other aircraft? [closed]

How is MCAS in 737 MAX 8 different from the stick pusher in MD80 or DHC8 and from the Airbus alpha protection, in terms of overall safety? All these systems will push the nose down at high AoA and ...
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Why doesn't the A330/A340 have a stickshaker?

When an A330/40 is in alternate law1 and approaching a stall, it has a stall warning composed entirely of a cricket chirp and a voice saying "stall, stall". Most other aircraft, in contrast, have a ...
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Why do aircraft stall warning systems use angle-of-attack vanes rather than detecting airflow separation directly?

Stall warning and protection systems on essentially all aircraft work by using several hinged vanes on the side of the fuselage (usually at least three, and preferably more), which align themselves ...
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1answer
115 views

Is there an increased concern for stall safety in a 1G steep turn?

Most people know the standard, "At a 60 degree bank, an aircraft experiences 2G's" checkpoint for load-factor on an airplane. I assume that this statement has an underlying, unspoken assumption that ...
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2answers
498 views

What is the difference between static and dynamic stall?

What are the static and dynamic stalls on the aircrafts wing? When would we encounter static and when dynamic one? What is the difference between them?
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2answers
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How can I tell from the location of flow separation if an airfoil is stalled?

I am in the process of completing a carbon airfoil for my track car (sedan) and I am looking to determine stall angle visually. AKA, wool tufts and highway runs with my GoPro pointed upward from the ...
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3answers
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Has the Boeing 737 MAX MCAS system successfully prevented a stall or approach to stall condition outside testing?

The Boeing 737 MAX MCAS system has been in the press a lot as it has been implicated as a possible cause of 2 fatal crashes. The MCAS system was put in to prevent a wing stall caused by excessive ...
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In the compressor characteristic, how do I calculate the minimum flow?

I have a small question, how do I determine the minimum flow point on the compressor characteristic? I.e. what is the safety margin on the curve?
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5answers
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Why do passenger jet manufacturers design their planes with stall prevention systems?

I understand why passenger jets use software that overrides pilot inputs that might cause the jet to exceed the flight envelope. But why do passenger jet manufacturers design their planes with stall ...
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1answer
585 views

Why is the A330/A340's angle-of-attack protection disabled in alternate law, even if the AoA vanes are operating normally?

Reading about Air France Flight 447, to quote Wikipedia (emphasis added): ... A second consequence of the reconfiguration into alternate law was that stall protection no longer operated. Whereas in ...
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2answers
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What is a rudder or fin stall?

What is a rudder or fin stall, how will the aircraft behave in that situation, and how should the pilot recognise it? What is the recovery procedure? And what is rudder reversal?
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2answers
356 views

How do aircraft stall warning systems handle (or not) asymmetric-stall situations?

Most, if not all, new airplanes are required to have stall warning systems to (as the name should make clear) provide the pilots with a warning when the airplane is about to stall. Most stall warning ...
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3answers
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Why is this video of a G36 Bonanza taking off so scary?

Why is this video of a G36 Bonanza so 'scary'? If they had clipped the top of the trees, would it really have brought the plane down? (And even if yes, it looks pretty ...
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2answers
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Why don’t aircraft have interlocks to prevent high-lift devices from being retracted when doing so would stall the airplane?

Most aircraft have high-lift devices on the wings (such as flaps, slats, droops, whatevs) to allow them to take off and climb out at a reasonable speed instead of having to accelerate to near ...
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2answers
548 views

Why does a sharp leading edge result in a larger pressure peak?

I know in the real world the sharp leading edge (LE) will results in a larger pressure peak compared to a large radius LE. And that there are three types of stall. But I want the explanation in ...
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2answers
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What prevents BFS from becoming unstable when pitching from horizontal to vertical?

In this video from (SpaceX's BFS landing) there is a point where the ship tilts from horizontal « belly first » terminal velocity freefall, to vertical « engine first » landing position. The graph ...
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3answers
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Mechanical vs Pneumatic Stall Warning Systems

Light Cessna aircraft - at least the high wing single engine line - have commonly made use of a solid state pneumatic stall warning system. The system is fairly unique to Cessna airplanes and makes ...
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4answers
2k views

Why does the Ikarus C42 pitch down when stalled?

Apparently, the C42 nose pitches down shortly after stall, like in this video. I know part of the video might be pilot input to recover from the stall, but I've read on various flying forums that this ...
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2answers
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Is there an abnormal condition that could have caused this fatal accident involving a stall?

In 2009, a Grob 103 glider stalled and crashed at Richmond Field, Michigan, killing the passenger but not the pilot. (NTSB accident report: CEN09LA353) The accident occurred after a failed winch ...