What Is a Stall?

An aircraft stall has nothing to do with the engine "stalling."

It is an aerodynamic event.

A wing stalls when it reaches and exceeds its critical angle of attack. At that point, airflow separation over the wing increases enough that the wing can no longer produce lift in the normal way.

That explains several things that otherwise seem contradictory:

• An airplane can stall with full engine power.
• It can stall at a high airspeed.
• It can stall while pointing downward.
• It can stall during a steep turn even though the airspeed indicator appears comfortably above the published stall speed.

Low airspeed is commonly associated with stalls because slowing down usually requires the wing to operate at a higher angle of attack to keep supporting the aircraft.

But low speed is not the underlying cause.

Excessive angle of attack is.

That distinction is one of the most important ideas in basic aerodynamics.

What Is an Aircraft Stall?#

A wing produces lift by establishing a pressure distribution around itself and changing the direction and momentum of the surrounding airflow.

The angle at which the wing meets that airflow is its angle of attack.

More precisely, angle of attack is the angle between the wing's chord line and the relative wind.

Within the wing's normal operating range, increasing angle of attack generally increases lift.

But only up to a point.

Eventually the wing reaches its critical angle of attack.

Beyond that angle, airflow separation over the wing becomes extensive enough that its lift coefficient decreases and drag rises sharply.

The wing has stalled.

Importantly, a stalled wing does not suddenly produce zero lift.

It can still produce a considerable aerodynamic force.

The important change is that the normal relationship between increasing angle of attack and increasing lift has broken down. The aircraft may develop a high sink rate, reduced control effectiveness, buffet, a nose drop, a wing drop, or some combination of these effects.

For the broader explanation of how wings generate lift in the first place, see How Airplanes Fly.

Critical Angle of Attack Is the Key#

If there is one idea to remember about stalls, it is this:

A wing stalls when it exceeds its critical angle of attack.

Not when it reaches one universal airspeed.

Not when the nose reaches one particular pitch attitude.

Not when the engine stops.

The actual critical angle depends on the aerodynamic design and condition of the wing.

There is therefore no single critical-angle number that pilots can apply to every airplane.

Aircraft configuration and contamination can also alter the wing's aerodynamic behavior.

A pilot should use the aircraft's approved procedures, warning systems, operating speeds, and handling characteristics rather than assume that every airplane stalls at the same angle.

Angle of Attack Is Not the Same as Pitch#

This distinction causes a lot of confusion.

Pitch describes the aircraft's orientation relative to the horizon.

Angle of attack describes the relationship between the wing and the airflow approaching it.

Those are not the same thing.

An airplane can have its nose high without being stalled.

It can also have its nose below the horizon and still be stalled.

Consider a few examples.

A steep climb#

An airplane climbing steeply may have a visibly high nose attitude while still operating below its critical angle of attack.

Slow level flight#

An airplane can remain roughly level while operating at a relatively high angle of attack because the pilot is increasing angle of attack as airspeed decreases.

An abrupt pull-up#

An airplane traveling quickly with its nose initially low can experience a rapid increase in angle of attack if the pilot pulls aggressively.

The wing may stall even though the airplane still has considerable airspeed.

That is why simply looking at where the nose is pointing cannot tell you whether the wing is close to a stall.

Why Are Stalls Associated With Low Airspeed?#

If angle of attack causes the stall, why do pilots spend so much time talking about stall speed?

Because airspeed and required lift are closely related.

An airplane in steady flight has to produce enough aerodynamic force to support its weight.

When airspeed decreases, the wing generally has to operate at a higher lift coefficient to continue producing the required lift.

One way the pilot accomplishes this is by increasing angle of attack.

Keep slowing while continuing to demand the same lift, and eventually the wing reaches its critical angle.

So the common progression is:

lower airspeed → higher required angle of attack → critical angle reached → stall

But that is only one path to the stall.

Anything that requires the wing to produce much more lift can also bring it toward its critical angle.

That is why a stall can occur at a considerably higher airspeed during a high-load maneuver.

Stall Speed Is Not One Permanent Number#

Aircraft manuals publish stall speeds, but those numbers apply to defined conditions.

They are useful reference speeds—not a guarantee that the airplane cannot stall above them.

Common designations include:

• VS0 — the stall speed or minimum steady flight speed in the landing configuration
• VS1 — the stall speed or minimum steady flight speed in a specified configuration

The exact regulatory definition depends on the aircraft and certification basis, but the larger lesson is straightforward:

Published stall speeds describe particular test conditions.

Change the conditions and the speed at which the critical angle is reached can change.

Important factors include:

• Aircraft weight
• Load factor
• Flap configuration
• Center-of-gravity position
• Wing contamination
• Maneuvering
• Coordination
• Aircraft design

Weight Changes Stall Speed#

A heavier airplane requires the wing to produce more lift.

Since the wing has a maximum lift coefficient before it stalls, a heavier aircraft generally reaches that limit at a higher airspeed than the same aircraft at a lower weight.

So:

higher weight → higher stall speed

and

lower weight → lower stall speed

within the relevant configuration and operating assumptions.

Weight is only half of the loading question, however.

Where that weight is located matters too.

Aircraft must remain inside the approved CG envelope, because center of gravity influences handling, control authority, stability, and stall and spin recovery characteristics.

A very aft CG is particularly significant because it reduces longitudinal stability and can make stall or spin recovery more difficult.

A forward CG generally increases longitudinal stability but can require more tail downforce and greater control force.

The complete relationship is covered in Weight & Balance Explained.

Load Factor Can Make an Airplane Stall Much Faster#

One of the clearest demonstrations that there is no single stall speed is an accelerated stall.

Load factor describes the aerodynamic load acting on an aircraft relative to its weight and is commonly expressed in G.

During an ordinary unaccelerated condition, the airplane experiences approximately 1 G.

During a coordinated level turn, however, the wings have to generate additional lift to support the airplane while also turning it.

The steeper the bank, the greater the load factor required to maintain altitude.

As load factor increases, stall speed increases approximately with the square root of the load factor.

The 60-degree-bank example#

In a coordinated level turn at approximately 60 degrees of bank angle:

• Load factor is approximately 2 G.
• Stall speed becomes approximately 1.41 times the one-G stall speed.

If an airplane stalls at 50 knots under the relevant one-G conditions, the theoretical stall speed at 2 G is roughly:

71 knots

That is about a 41 percent increase.

Nothing fundamental happened to the wing's critical angle.

The aircraft simply demanded much more lift from the wing, causing it to reach that angle at a higher airspeed.

This is known as an accelerated stall.

It can occur during:

• Steep turns
• Abrupt pull-ups
• Aggressive maneuvering
• Rapid recovery from a dive
• Other high-load situations

What Actually Happens to the Airflow During a Stall?#

At normal angles of attack, much of the airflow around the wing remains attached to the surface in a pattern that allows the wing to generate its expected aerodynamic force.

As angle of attack increases, maintaining that attached flow becomes progressively more difficult.

The thin region of airflow close to the wing's surface—called the boundary layer—has to move through an increasingly challenging pressure gradient.

Eventually portions of the flow separate.

As the critical angle is reached and exceeded, that separation becomes extensive enough that the wing's lift coefficient begins to decrease.

At the same time, drag generally increases substantially.

This is why pulling back harder after a stall is exactly the wrong fundamental response.

Increasing angle of attack further does not restore the missing lift.

It deepens the stalled condition.

Not Every Wing Stalls the Same Way#

Aircraft designers can influence how a wing behaves as it approaches a stall.

Factors include:

• Airfoil shape
• Wing planform
• Wing twist
• Camber
• High-lift devices
• Wing loading
• Control-surface arrangement
• Center of gravity
• Power effects

Many training aircraft are designed to encourage the wing root to stall before the outer portions of the wing.

That can help preserve useful airflow over the ailerons and provide more predictable handling near the stall.

But no pilot should assume that every wing will behave that way in every condition.

Ice, frost, yaw, contamination, configuration, or abrupt maneuvering can alter the stall behavior considerably.

Why Can One Wing Drop During a Stall?#

An airplane does not always stall perfectly symmetrically.

If one wing is operating at a higher effective angle of attack than the other, or one side experiences more severe airflow separation, the two wings can produce different amounts of lift and drag.

The airplane may then roll and yaw toward the more deeply stalled side.

This becomes especially important because instinctively applying large opposite aileron while the wing is deeply stalled may not always help.

A downward-deflected aileron can increase local angle of attack and drag on part of the wing.

Depending on the aircraft and situation, that can deepen the stall on the wing the pilot is trying to raise.

The first aerodynamic problem remains the excessive angle of attack.

Reduce that, then restore the aircraft using the coordinated controls and aircraft-specific recovery procedure.

For more on how the controls interact, see Control Surfaces Explained.

Flaps Change Stall Characteristics#

Flaps alter the geometry of the wing.

Depending on the aircraft and flap setting, deploying them can increase wing camber and maximum lift coefficient.

That usually reduces the stall speed for a given weight and loading condition.

But flaps also change:

• Drag
• Pitching moments
• Handling
• Critical-angle characteristics
• Recommended operating speeds

They do not make a wing incapable of stalling.

The airplane simply reaches its aerodynamic limit under a different combination of speed, configuration, and angle of attack.

This is why pilots use different reference and stall speeds for different aircraft configurations.

Wing Contamination Can Change Everything#

A clean wing and a contaminated wing may behave very differently.

Ice, frost, snow, or other contamination can disturb the carefully shaped airflow over the surface.

The results may include:

• Reduced maximum lift
• Increased drag
• A lower critical angle of attack
• A higher stall speed
• Different stall-warning cues
• Different handling near the stall
• Asymmetric stall behavior

That last point matters particularly when one wing is contaminated differently from the other.

A pilot cannot safely assume that the aircraft will provide the same buffet, warning margin, or stall behavior it demonstrated with a clean wing.

See Aircraft Icing Explained for the aerodynamic effects of ice in more detail.

Does Altitude Change Stall Speed?#

This requires distinguishing indicated airspeed from true airspeed.

For a conventional subsonic airplane at the same weight, configuration, load factor, and aerodynamic condition, altitude has relatively little direct effect on the indicated airspeed associated with the basic one-G stall.

But the true airspeed corresponding to that indicated speed increases as air density decreases.

That means the aircraft can be moving through the air—and over the ground in still-air conditions—faster even though the indicated airspeed at the stall looks familiar.

Higher density altitude can also reduce:

• Engine performance
• Propeller performance
• Climb performance

and increase:

• Takeoff distance
• Landing distance
• True airspeed for a given indicated airspeed

So altitude does not make the wing forget its critical angle of attack.

It changes the performance environment around the stall.

See Density Altitude Explained for the wider performance picture.

Common Situations That Can Lead to a Stall#

A stall can occur in almost any phase of flight.

Some situations deserve particular attention because they combine high angle of attack with little altitude or little time to recover.

Departure Stall#

Shortly after takeoff, the airplane is climbing close to the ground.

A departure stall can develop if the aircraft is commanded to an excessive angle of attack.

Possible contributing situations include:

• Excessively steep pitch after takeoff
• Trying to clear an obstacle by continuing to pull back
• Losing airspeed during the climb
• Distraction
• Improper trim
• Increasing bank and load factor during a climbing turn
• Mismanaging pitch during a power change

An important point here is that the engine may be producing substantial or even full power.

Power does not prevent the wing from exceeding its critical angle of attack.

Approach-to-Landing Stall#

Approach and landing combine several risk factors:

• Relatively low airspeed
• Low altitude
• Frequent configuration changes
• Turns
• Wind changes
• High workload

If the aircraft gets low on the approach, the pilot may be tempted to raise the nose to "stretch" the glide.

That can temporarily change the flight path, but it also trades away airspeed and raises angle of attack.

Continue demanding lift this way and the wing can reach its critical angle.

A stable approach and an early go-around are far safer than trying to force an airplane onto a runway from an unstable position.

The Base-to-Final Stall and Spin Risk#

One classic high-risk scenario occurs when a pilot overshoots the final approach course during the turn from base to final.

The temptation may be to tighten the turn using excessive rudder while resisting the increasing bank with opposite aileron.

That creates a cross-control condition and can produce a skid.

If the wing then stalls while substantial yaw exists, the aircraft can transition rapidly toward a spin.

Near the ground, there may be nowhere near enough altitude for recovery.

The safer solution to an overshoot is generally simple:

Go around and try again.

Accelerated Stall#

An accelerated stall occurs when an aircraft stalls while carrying more than a one-G load.

This can happen during:

• A steep level turn
• An abrupt pull-up
• Aggressive maneuvering
• Recovery from a dive
• Other high-load-factor situations

The airplane may stall well above the familiar published one-G stall speed.

Again, the critical angle has not changed merely because the airplane is traveling faster.

The wing is being asked to generate more aerodynamic force, so it reaches the critical angle at that higher speed.

Go-Around and Trim-Related Stall#

A go-around can create large and rapid changes in forces.

Applying power can produce aircraft-specific pitching and yawing tendencies.

If the airplane was significantly trimmed for approach and the pilot does not manage those forces, the nose may rise more aggressively than intended.

A stall can therefore occur during a go-around despite high power.

This is another example of why power setting does not determine whether a wing can stall.

What Does a Stall Feel Like?#

There is no universal stall sensation.

The cues depend on the aircraft, configuration, loading, and circumstances.

Possible indications include:

• Stall-warning horn or alert
• Buffet
• Reduced control effectiveness
• Increasing control displacement
• High sink rate
• Nose drop
• Wing drop
• Yaw
• Stick shaker
• Stick pusher on equipped aircraft
• Angle-of-attack indication

Some airplanes provide substantial natural warning before the stall.

Others can be more abrupt.

Turbulence or contamination can also mask or alter normal cues.

Pilots therefore learn the actual stall characteristics and warning systems of the aircraft they operate.

Stall Warning Systems#

A stall warning system is designed to provide warning as the aircraft approaches the stalled condition.

Depending on the airplane, the system might use:

• A horn
• A buzzer
• A light
• A stick shaker
• A stick pusher
• Electronic or voice alerts

Some airplanes also provide angle-of-attack information.

The warning should not be treated as a normal target.

It exists to warn that the available stall margin has become dangerously small.

And a pilot should not assume that every warning system behaves identically under icing, unusual configurations, failures, or other abnormal circumstances.

Aerodynamic Buffet#

As airflow begins separating, turbulent flow can strike portions of the wing, tail, or airframe.

The pilot may feel this as buffet.

In some aircraft it provides a strong natural warning.

In others it may be subtle.

And in atmospheric turbulence, the aerodynamic buffet associated with the approaching stall may be much harder to distinguish.

Buffet is therefore one possible cue—not a universal stall detector.

Reduced Control Effectiveness#

At lower airspeeds, aerodynamic forces over conventional control surfaces generally become weaker.

The pilot may notice that the controls feel less precise or require larger movements to produce the same aircraft response.

This is sometimes described as "mushy controls."

That can be a useful training cue, but it is not a precise definition of a stall and should not be expected to appear identically in every aircraft.

Angle-of-Attack Indicators#

Some airplanes have angle-of-attack displays that provide additional information about stall margin.

These can be useful because the underlying aerodynamic limit is angle of attack rather than one fixed airspeed.

But an AOA system must be:

• Correctly installed
• Correctly calibrated
• Properly interpreted
• Used within its limitations

An AOA display supplements the aircraft's approved procedures and the pilot's understanding of energy and flight condition.

It does not replace them.

How Pilots Prevent Stalls#

The safest stall recovery is the one that never becomes necessary.

Prevention is largely about recognizing when the aircraft is moving toward the critical angle of attack.

That includes:

• Flying the speeds published in the AFM or POH
• Maintaining coordinated flight
• Monitoring airspeed trends
• Understanding angle-of-attack cues
• Recognizing increasing load factor
• Accounting for weight and configuration
• Maintaining the aircraft inside its approved CG envelope
• Avoiding abrupt control inputs
• Managing pitch and power properly during takeoff and go-around
• Avoiding contaminated wings
• Going around from an unstable approach
• Never trying to force an overshot turn back onto final

Pilots practice stall recognition and recovery during training precisely because recognizing the developing condition early is far better than allowing the stall to fully develop.

The Fundamental Principle of Stall Recovery#

The aerodynamic requirement for recovering from a stall is straightforward:

Reduce angle of attack below the critical angle.

Until that happens, the underlying stall has not been corrected.

Adding power by itself cannot guarantee recovery.

Trying to hold altitude cannot guarantee recovery.

Trying to level a deeply stalled wing without addressing angle of attack does not fix the fundamental problem.

The wing has to return to an unstalled angle of attack.

Generic FAA Stall-Recovery Framework#

Recovery procedures are aircraft-specific.

A pilot must follow the approved AFM, POH, checklist, manufacturer procedure, and training applicable to the airplane being flown.

At a general conceptual level, FAA guidance for conventional airplanes emphasizes a sequence built around these principles:

1. Disconnect automation when applicable#

In an aircraft using systems such as an autopilot or autothrottle, the appropriate procedure may require disconnecting automation so it does not resist or obscure the necessary recovery inputs.

2. Reduce angle of attack#

Apply enough nose-down control input—or otherwise reduce the commanded angle of attack as required by the aircraft—to eliminate the stalled condition.

This is the essential aerodynamic step.

Exactly how much control input is required depends on the aircraft and severity of the stall.

3. Level the wings with coordinated controls#

Once angle of attack is being reduced, restore the desired bank using the aircraft's recommended coordinated-control technique.

Avoid assuming that an aggressive aileron input is always appropriate while a wing remains deeply stalled.

4. Apply power or thrust as needed#

Additional thrust can help restore energy and reduce altitude loss.

But maximum power is not universally the first action or the correct amount for every aircraft.

Power application can create:

• Pitch effects
• Torque
• P-factor
• Asymmetric thrust
• Directional-control challenges

The aircraft-specific procedure determines how power should be used.

5. Reconfigure as required#

Spoilers, speed brakes, flaps, gear, and other systems should be handled according to the approved recovery procedure.

6. Return to the desired flight path#

As the aircraft recovers, the pilot restores the desired flight path while avoiding excessive airspeed, structural loading, or another stall.

Some altitude loss may be unavoidable.

That is preferable to keeping the wing stalled in an attempt to save altitude.

Why "Push Forward and Add Full Power" Is Too Simple#

Stall recovery is sometimes reduced to a slogan:

Push the nose down and add full power.

The first part captures the essential aerodynamic principle—the angle of attack has to decrease.

The second part is not universal.

Maximum power can create powerful pitch or yaw effects in some airplanes.

In multiengine aircraft, asymmetric thrust may complicate directional control.

At high altitude, jet-engine response and aircraft energy state introduce additional considerations.

Different manufacturers may specify different recovery actions.

A better universal statement is:

Reduce angle of attack first, then use power as needed according to the aircraft's approved procedure.

Secondary Stalls#

Breaking the original stall is not the end of the recovery.

If the pilot immediately pulls back too aggressively in an attempt to stop the descent, angle of attack can increase to the critical value again.

The aircraft stalls a second time.

This is called a secondary stall.

It demonstrates why altitude loss cannot always be prevented during recovery.

The objective is to restore controlled, unstalled flight without creating excessive structural loading or immediately exceeding the critical angle again.

Stall Versus Spin#

A stall and a spin are related, but they are not the same event.

An aerodynamic stall occurs when the wing exceeds its critical angle of attack.

A spin is an aggravated stalled condition involving autorotation.

In a spin, the airplane is stalled while yaw causes the two wings to experience different aerodynamic conditions.

One wing may be more deeply stalled than the other, producing the imbalance of lift and drag that sustains the autorotation.

So:

Every aerodynamic spin involves a stall.

But:

Most stalls do not become spins.

Yaw is the crucial additional ingredient.

That is why maintaining coordination near the stall is so important.

Why a Skid Near the Stall Is Dangerous#

During a skid, excessive rudder causes the airplane's nose to yaw toward the inside of a turn relative to the aircraft's bank.

If the aircraft is also close to its critical angle of attack, the asymmetry between the wings can become dangerous.

A stall combined with significant yaw can produce rapid roll and spin entry.

The base-to-final overshoot scenario is the classic example:

1. The airplane overshoots final.
2. The pilot adds excessive inside rudder.
3. Opposite aileron may be used to prevent the bank from increasing.
4. Angle of attack continues increasing.
5. The aircraft stalls while yawed.
6. The aircraft can enter a spin at very low altitude.

The proper solution is not to become better at forcing that turn.

It is to recognize the unstable situation and go around before it develops.

Can Modern Airliners Stall?#

Yes.

A transport airplane's wing still has a critical angle of attack.

Modern aircraft may provide sophisticated protection and warning systems such as:

• Stick shakers
• Stick pushers
• Angle-of-attack sensing
• Automatic protections
• Flight-director logic
• Fly-by-wire envelope protections

Those systems can make an inadvertent stall less likely or give the crew stronger warning.

They do not repeal aerodynamics.

Aircraft protections also differ significantly among manufacturers and airplane types.

This is why transport-aircraft stall prevention and recovery training remains an important part of professional flight training.

Common Myths About Aircraft Stalls#

Myth: A stall means the engine stopped#

No.

An engine failure affects propulsion.

A wing stall is an aerodynamic condition caused by excessive angle of attack.

An airplane can have working engines and stalled wings, or failed engines and perfectly unstalled wings.

Myth: An airplane stalls at one specific speed#

Not universally.

Published stall speeds apply to specified conditions.

Weight, load factor, configuration, contamination, and other factors can change the airspeed at which the critical angle is reached.

Myth: An airplane cannot stall while flying fast#

It can.

High load factor can cause the wing to reach its critical angle at a much higher airspeed than the ordinary one-G stall speed.

Myth: The nose has to be pointing upward#

No.

Pitch attitude and angle of attack are different.

An aircraft can stall while level or nose-down.

Myth: More power always fixes a stall#

No.

Power can help restore energy, but it does not eliminate the aerodynamic requirement to reduce angle of attack.

Myth: Pulling back prevents the airplane from losing altitude#

During a stall, pulling back further increases angle of attack and can deepen the stalled condition.

Some altitude loss during recovery may be necessary.

Myth: Stall warning always gives plenty of time#

Warning margins vary with aircraft, configuration, contamination, maneuvering, and other conditions.

A stall-warning device is an alert—not permission to deliberately operate indefinitely at the warning threshold.

Frequently Asked Questions#

Key Takeaways#

• An aircraft stall is an aerodynamic event, not an engine failure.
• A wing stalls when it exceeds its critical angle of attack.
• Low airspeed often leads to a stall because it requires the wing to operate at a higher angle of attack, but low speed itself is not the fundamental cause.
• An airplane can stall at high airspeed, at full power, or while its nose is below the horizon.
• Pitch attitude and angle of attack are different.
• Published stall speeds apply to specified conditions rather than representing one permanent aerodynamic limit.
• Higher aircraft weight generally increases stall speed.
• Increasing load factor increases stall speed; at approximately 2 G, the theoretical stall speed is about 41 percent higher than at one G.
• Flaps, center of gravity, wing contamination, and aircraft configuration can change stall characteristics.
• Ice and frost can reduce maximum lift, increase drag, alter stall warnings, and change the critical angle at which the wing stalls.
• A wing drop can occur when the two wings do not stall symmetrically.
• Stall prevention is primarily about managing angle of attack, energy, loading, configuration, and coordination before the critical angle is reached.
• The essential aerodynamic recovery principle is to reduce angle of attack below the critical angle.
• Power can help restore energy but should be applied as required by the aircraft-specific recovery procedure; maximum power is not a universal first step.
• Pulling up too aggressively after breaking the stall can cause a secondary stall.
• A spin is an aggravated stalled condition involving yaw and autorotation.
• Aircraft-specific AFM, POH, checklist, manufacturer guidance, and approved training always take precedence over generic stall-recovery guidance.

Sources & References#

• FAA Airplane Flying Handbook (FAA-H-8083-3C). Chapter 5 covers stall recognition, prevention, recovery principles, secondary stalls, and spins.
• FAA Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C). Chapters on principles of flight and aerodynamics cover angle of attack, lift, load factor, stall speed, aircraft stability, and center-of-gravity effects.
• FAA Advisory Circular 61-67C, Change 2: Stall and Spin Awareness Training. Provides stall and spin awareness guidance and discusses operating factors affecting stalls.
• FAA Advisory Circular 120-109A: Stall Prevention and Recovery Training. Active FAA guidance emphasizing angle-of-attack reduction and appropriate stall-prevention and recovery training for transport airplanes.