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.
240
questions
12
votes
2
answers
3k
views
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 ...
- 11.8k
4
votes
1
answer
87
views
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 ...
4
votes
1
answer
152
views
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, ...
- 143
0
votes
0
answers
23
views
Why does changes in load factor affect the stalling speed? [duplicate]
Why does changes in load factor affect the stalling speed?
Is it because with an increase of load, the airplane has to fly at a faster airspeed to maintain performance because of the weight it has to ...
- 889
2
votes
1
answer
401
views
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 ...
- 11.8k
1
vote
1
answer
98
views
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 ...
- 41
12
votes
3
answers
3k
views
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?
- 6,472
2
votes
1
answer
247
views
Helicopter hammerhead-like maneuver
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 ...
- 21
6
votes
3
answers
2k
views
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 ...
- 6,472
0
votes
1
answer
66
views
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 ...
- 129
3
votes
1
answer
169
views
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, ...
- 143
5
votes
1
answer
303
views
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 ...
- 28k
1
vote
2
answers
131
views
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 ...
- 41
4
votes
1
answer
145
views
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....
- 161
3
votes
0
answers
51
views
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 ...
- 1,185
0
votes
0
answers
50
views
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
4
answers
241
views
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 ...
- 6,472
1
vote
3
answers
592
views
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?
- 97
0
votes
1
answer
213
views
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.
...
7
votes
5
answers
2k
views
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 ...
- 6,472
21
votes
8
answers
7k
views
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 ...
- 639
16
votes
4
answers
5k
views
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?
- 319
2
votes
2
answers
297
views
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 ...
- 1,630
4
votes
2
answers
546
views
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 ...
- 41
1
vote
1
answer
364
views
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 ...
- 11
1
vote
1
answer
306
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 ...
- 23
8
votes
2
answers
2k
views
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 ...
2
votes
1
answer
84
views
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 ...
- 467
4
votes
3
answers
1k
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 ...
- 193
8
votes
2
answers
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 ...
3
votes
4
answers
495
views
Can a plane still climb even if it has exceeded the critical AoA?
According to this answer here, an airplane requires less lift for a climb than horizontal flight because the thrust of the engines will point up.
Now if the wing was in a stall condition, could the ...
-2
votes
1
answer
101
views
Stall speed requirement [closed]
I calculated my stall speed at 22m/s.
For this stall speed, would it be a better idea to increase it to use in my calculations later on or leave it as it is?
I thought increase it a little to be on ...
- 1
1
vote
1
answer
151
views
Can vane delay flow separation? [closed]
In general is a slat better than a vortex generator to delay flow separation, for high AoA or extremely curvature wing/objects?
Does this "roof vane spoiler" works same as slat at wing, ...
- 1,630
0
votes
1
answer
150
views
What is max angle of surface without stall?
AoA is by defintion angle between choord line and airflow, here is 25°.
But max effective AoA here is 60°, so flow will separate for sure here..
What is max lets call it "effective AoA" that ...
- 1,630
-1
votes
1
answer
332
views
The stall velocity condition: Exactly what is stall velocity? [closed]
Question: if my stall velocity is 20m/s, then...
If the airplane is travelling at a velocity greater than or equal to the stall velocity, can one assume the plane will not stall?
Can one assume that ...
- 19
0
votes
3
answers
401
views
What is the AeroVironment Helios' Kármán line?
If it's true that the NASA/AeroVironment Helios maintained level flight 96,000 ft above sea level at a maximum airspeed of 23.5 kts (43.5 km/h) I assume it must have a very high Kármán altitude, the ...
- 997
0
votes
1
answer
126
views
Attack angle in high speed [closed]
I found the above animation; the moving slow air (or wing) will hardly to lead to an aerodynamic stall, but the usual case is a plane in the air running much faster than the animation, so does the ...
- 11
7
votes
1
answer
4k
views
What is the difference between Vs and Vs1g?
As the name suggests, what is the difference between Vs1g and Vs?
If both of them are referring to the stall condition, why they aren't the same?
Which one is usually greater and why? Why do we need a ...
- 1,135
5
votes
4
answers
2k
views
Why does lift decrease and drag increase when approaching the stall condition?
This is an ECQB-PPL question specifically asking what happens before the stall. I do understand that after the critical angle has been reached, the airfoil is no longer generating lift (so obviously ...
9
votes
2
answers
3k
views
What caused this crash landing?
Watching this video, my attention was triggered by the quite firm right rudder deflection, just before the right wing stalls.
There's no information about what ...
- 4,368
6
votes
1
answer
2k
views
Can a wing be stalled at a speed larger than its stall speed?
I was told pulling the yoke quickly and all the way back stalls the plane immediately. I believe this is not possible as long as this occurs above the stall speed.
I think about a styrofoam plane: ...
- 1,630
1
vote
1
answer
171
views
How was the AeroVironment Helios able to fly to the edge of space at no more than 23.5 kn?
The NASA/AeroVironment Helios holds the FAI record for the highest sustained horizontal flight at 96,900 ft (29.5 km) MSL. It reportedly spent more than 40 min above 96,000 ft. It could fly no faster ...
- 83
3
votes
2
answers
853
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 ...
- 349
2
votes
5
answers
430
views
What do you call a fall that is due to too little engine power, not due to cessation of aerodynamic lift?
If you raise your plane's pitch but the engines can no longer counter the gravity and you begin to fall (because the engines are too weak, not because of too little lift), what do you call that? This ...
- 533
8
votes
4
answers
2k
views
What effect does towing a glider have on the stall speed of the tow plane?
I can see that if the tow is perfectly aligned with the axis of the engine thrust, that it is equivalent to pure parasitic drag and similar to some reduction of thrust. However, in the real world the ...
- 512
11
votes
2
answers
2k
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 ...
- 111
0
votes
0
answers
105
views
Is the L-39 Albatros able to go above 40,000 ft in steep flight?
The L-39's service ceiling is 36,100 ft / 11 km but would it be able to easily reach and surpass 40,000 ft MSL if flying a parabola?
- 533
1
vote
1
answer
176
views
How to turn inviscid data to viscous?
I have used Panel method to calculate Cp vs x/c graph and CL. But as panel method assumes attached flow it does not give an flow separation and thus in CL vs alpha graph I could not find any stall. My ...
-4
votes
1
answer
5k
views
What is the explanation for the appearance of airplanes hovering? [duplicate]
A few weeks ago, I saw a plane that appeared to be hovering in the air. It was a large commercial airliner. It was not a windy day, land speeds of 24km/h max that day, about 5km/h at the time I saw it ...
- 11
0
votes
1
answer
90
views
Why is the definition of $V_{S1}$ vague wrt configuration?
The definition of $V_{S1}$ is
the stalling speed or the minimum steady flight speed obtained in a specific configuration
from 14 CFR §1.2 Abbreviations and symbols.
Why is this vague in terms of the ...
- 151