We’re rewarding the question askers & reputations are being recalculated! Read more.

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.

Filter by
Sorted by
Tagged with
1
vote
1answer
82 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 ...
4
votes
1answer
236 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 ...
0
votes
1answer
95 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 ...
5
votes
1answer
144 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
1
vote
1answer
51 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 ) ?
1
vote
1answer
141 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.
0
votes
2answers
267 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 ...
1
vote
1answer
216 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
votes
1answer
295 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 ...
1
vote
1answer
82 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 ...
1
vote
1answer
120 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 ...
2
votes
1answer
128 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 ...
3
votes
1answer
74 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 ...
24
votes
5answers
3k views

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 ...
6
votes
3answers
505 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 ...
6
votes
2answers
982 views

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 ...
0
votes
0answers
80 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 ...
2
votes
1answer
137 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 ...
4
votes
4answers
316 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. ...
9
votes
2answers
758 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 ...
0
votes
1answer
153 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 ...
3
votes
3answers
218 views

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.
3
votes
0answers
56 views

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 ...
0
votes
3answers
157 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?
1
vote
3answers
432 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 ...
0
votes
0answers
116 views

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 ...
6
votes
4answers
527 views

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 ...
1
vote
1answer
107 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 ...
5
votes
2answers
422 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?
3
votes
2answers
123 views

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 ...
7
votes
3answers
723 views

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 ...
1
vote
0answers
13 views

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?
15
votes
5answers
6k views

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 ...
6
votes
1answer
526 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 ...
5
votes
2answers
614 views

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?
1
vote
2answers
335 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 ...
2
votes
3answers
910 views

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 ...
4
votes
2answers
230 views

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 ...
4
votes
2answers
450 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 ...
8
votes
2answers
462 views

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 ...
1
vote
3answers
350 views

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 ...
6
votes
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 ...
16
votes
2answers
3k views

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 ...
1
vote
1answer
567 views

Difference between Mach buffet and shock stall

What is the difference between Mach buffet and shock stall?
1
vote
1answer
1k views

What is primary cause of shock induced separation (shock stall)?

In the video link above describing Prandtl Meyer Waves, lecturer stated (at 22:40) a very important fact on which he based his first half of the lecture. "Mach wave (mach lines) deflect the flow ...
7
votes
1answer
4k views

Why does a rectangular wing stall first at the root?

Why does a rectangular wing stall first at the root? as opposed to tapering of the wing which causes the stall at the tip and moving inboard?
14
votes
7answers
6k views

Why does a stall decrease lift, rather than increasing it?

A stall occurs when the angle of attack of a wing or other airfoil becomes so high that the airflow over the upper surface of the wing separates from the wing, rather than remaining attached to it; ...
6
votes
1answer
234 views

Can this vane prevent/delay wing stall?

Given that a stall results from the airflow over the top of the wing separating from the wing at high angles of attack, would it be possible to prevent, or at least ameliorate, a stall by deflecting ...
4
votes
2answers
795 views

How can I compute the minimum possible bank angle for a turn with a given radius?

I know that I can find an upper bound for the bank angle for a plane, if I know the maximum sustained load factor of that plane because the roll angle and the load factor $n_z$ in a turn are directly ...
5
votes
1answer
349 views

Definition of a Deep Stall

I've been doing some research for a uni assignment and I noticed that the RQ-11B uses a "deep stall landing" to get back onto the ground. What I don't understand though is how this aircraft gets into ...