Airplane Stall &Recovery Procedures
Introduction:
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Stalls occur when the airflow over an aircraft's control surface has been
interrupted sufficiently to cause separation
• Review Stall performance
Pilots must therefore be aware of the conditions which increase stall potential
Although unintentional stalls are never desirable, understanding stall
characteristics allow a pilot to recognize the situation so as to provide the
appropriate recovery procedure
In training, pilots will perform approaches to stalls to practice the various regimes
where stalling may occur, and how to recovery from each
There are six principal stall maneuvers which include power-off, power-on, crosscontrolled, elevator-trim, and secondary stalls
• Power-off stalls simulate a stall under low-powered conditions like during a
normal approach to landing
• Recoveries therefore train a pilot to make prompt, positive, and
effective recoveries with a minimum loss of altitude
• Power-on stalls simulate a stall under higher powered conditions like
during a normal takeoff and departure
• Recoveries emphasize how aircraft attitude impacts stall potential,
again simulating a stall close to the ground, and trains a pilot to
recover with a minimum loss of altitude
• Elevator Trim Stalls demonstrate the effects of not maintaining positive
airplane control during a go-around/rejected landing
• Recoveries emphasize aircraft configuration as it similarly applies
to a power-on stall situation, requiring swift identification and
recovery application
• simulate stalls that may not only occur in a turn, but an uncoordinated turn
• Recoveries emphasize the importance of coordinated turns and the
stall characteristics associated with flight controls deflected at the
time of the stall
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Accelerated stalls demonstrate the effect of aggressive maneuvering and
the ability to abruptly break airflow
Secondary stalls demonstrate aggressive recoveries that have the
potential to induce another stall after recovery from a preceding stall
• Recoveries emphasize smooth recovery procedures so as not to
aggravate a stall condition
Stall Avoidance:
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Avoid flying at minimum airspeeds
Remain in the normal flight envelope
Avoid abrupt maneuvers
"Pilots MUST therefore BE AWARE of conditions which INCREASE STALL potential
👍 STALLS are ultimately brought on by exceeding the CRITICAL ANGLE of ATTACK
(CAoA)
A)Angle of Attack (AoA/Alpha): The angle between the RELATIVE wind & CHORDLINE of an airfoil
B)Critical AoA: The angle of attack whereby any further increase will result in a
SEPARATION of AIRFLOW which results in a STALL
Although unintentional stalls are never desirable UNDERSTANDING stall
characteristics
ALLOW a pilot to RECOGNIZE situation so as to PROVIDE the APPROPRIATE
recovery procedure
In TRAINING pilots WILL perform approaches to STALLS to practice the various
regimes where STALLING may occur & how to recovery from each
SIMULATE stalls that may not ONLY occur in *a TURN but *an UNCOORDINATED
turn
Recoveries emphasize the importance of
*COORDINATED TURNS &
*STALL characteristics associated with
*flight controls DEFLECTED at the time of the stall
WARNING:
All procedures are GENERALIZED
👍 Always fly per
*POH - Pilot Operating Handbook procedures
*OBSERVING any relevant Standard Operating Procedures (SOPs)
Stalls do NOT occur without WARNING
While flying along in cruise flight
*a stall WILL NOT
*RIP the airplane out of the sky & *throw it UNCONTROLLABLY to the ground to a big
smoking crater
At HIGH LOAD FACTORS the SUDDEN LOSS of LIFT from one wing
*(whichever stalls first) creates a MUCH LARGE ROLLING moment than with a
*1 g stall
The result is
*a VIOLENT DEPARTURE
that resembles a
*SNAP ROLL
It is important to NOTE that individual aircraft MAY have STALL CHARACTERISTICS
unique to them
*due to BENDS /TWISTS
which develop in the airframe over time depending on their use
To get more in depth about what is occurring during a stall
👍 be SURE TO READ
*STALL performance page
Stalls are most likely to occur UNEXPECTEDLY
Since a STALL
👎 is most likely to be FATAL when in the TRAFFIC PATTERN
👍 consider flying a SIMULATED TRAFFIC PATTERN at altitude &
*assess reaction/altitude IMPACTS
1) Although POWER-OFF stalls can happen in various regimes of flight
RECOVERY PROCEDURES are PARTICULARLY important while on an
*APPROACH to LANDING
2) Although POWER-ON stalls can happen in various regimes of flight
RECOVERY PROCEDURES are particularly important while on an
*TAKE-OFF
&
*CLIMB
When
👍TEACHING STALLS avoid mechanical steps
but
INSTEAD introduce a stall when
👍 UNEXPECTED
as that's the most likely scenario to encounter
Stall Speed Considerations:
As AoA increases up to
*CL MAX AoA
*True Airspeed (TAS) decreases to a point where it cannot be any slower than stall
speed (Vs)
Airspeeds may change based on WEIGHT & CONFIGURATION
but
units of AoA remains the SAME. You can stall at any airspeed
3)Going TOO SLOW causes
HIGH AoA
4)While going TOO FAST cause
SHOCK WAVES
on aircraft not designed for SUPERSONIC or even TRANSONIC flight causing the
same disruption as HIGH AoA"
Stall Characteristics:
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If the airplane is slipping toward the inside of the turn at the time of the stall, it
tends to roll rapidly toward the outside of the turn as the nose pitches down,
because the outside wing stalls before the inside wing
If the airplane is skidding toward the outside of the turn, it will have a tendency to
roll to the inside of the turn, because the inside wing stalls first
If the coordination of the turn at the time of the stall is accurate, the airplane's
nose will pitch away from the pilot just as it does in a straight flight stall
Stalling will occur at a higher airspeed and thus, a lower than expected pitch
resulting in a quick, unexpected stall
If an uncoordinated turn is made, one wing may tend to drop suddenly, causing
the airplane to roll in that direction; if that occurs, the excess back-elevator
pressure must be released, power added, and the airplane returned to straightand-level flight with coordinated control pressure
Load Factor:
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Load factor is the weight the wings are supporting
Load factor is generally not calculated as part of preflight however, it has a close
relation to stall speed, which is very important
• As load factor increase, stall speed increases
In level flight, the load factor is the weight of the aircraft
• This is due to the aircraft feeling "1-g" or 1 times the force of gravity
As you increase the angle of bank however, a pilot must pull back on the controls
in order to avoid descending due to the loss of vertical lift, which then raises the
load factor
Calculating Load Factor:
• Pilots will generally rely on the 60° angle of bank is 2-Gs rule of thumb,
after all, performance charts are designed with the technical data
considered
• Still, pilots can be more precise if they chose by using some relatively
simple math
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Load Factor Formula:
Load Factor = 1 / cos(angle of bank)
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Conditions:
• Given an angle of Bank of 60°
Calculation:
• Load Factor = 1 / cos(60)
• Load Factor = 1 / 0.5
• Load Factor = 2
Chart:
[Figure 1]
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Look at the 60° mark at the bottom of the chart and move up until
you intercept the load factor reference line
Move over to the left and see the load factor imposed on the aircraft
• You should come up to approximately 2
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Load Factor vs. Stall Speed
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As mentioned above, stall speed increases with load factor due to a loss in
the vertical component of lift
Calculating Stall Speed:
• Load Factor Formula:
Stall Speed Banked = [Stall Speed Level x Square Root of Load Factor]
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Conditions:
• Given an aircraft with a stall speed of 48 knots with a load factor of
2 (60° angle of bank):
Calculation:
• Stall Speed Banked = [Stall Speed Level / Square Root of Load
Factor]
• Square Root of 2 = 1.41
• Stall Speed Banked = 48 x 1.41
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Stall Speed Banked = 68 KIAS
Chart:
[Figure 1]
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Look at the 60° mark at the bottom of the chart and move up until
you intercept the stall speed increase reference line
Move over to the left and see the percent increase in stall speed
• You should come up with an increase in stall speed of
approximately 41%
• Stall Speed Banked = [Stall Speed Level x percent
increase in stall speed]
• Stall Speed Banked = 48 x 1.41
• Stall Speed Banked = 68 KIAS
Approaches to Stalls:
1. Select an altitude where recovery will occur no lower than 1500' AGL
2. Commence a clearing turn
3. While maintaining heading, reduce power, adjusting pitch (trim) to maintain
altitude
4. For Dirty Configuration:
• Below VLO, extend the landing gear and verify 3 down and locked
• Below VFE, extend the flaps for takeoff or landing configurations
• Adjust pitch (trim) to maintain altitude
5. Advance the propeller control to full forward (high rpm) as required
6. While maintaining altitude, slowly establish the pitch attitude, power setting, and
if applicable, bank (15-30°) that would induce a stall
7. At the first indication of an impending stall, calling, "stalling," and initiate
recovery, maintaining heading while/ smoothly and continuously increasing
power to full and adjusting pitch to maintain altitude (trim)
8. For Dirty Configuration:
• As airspeed increases, raise the flaps in increments, to 10°:
• Too abrupt of flap retraction will result in a dramatic loss of lift and
possibly stall
• As airspeed increases, but below VLO raise the landing gear
• At or above Vx retract flaps to 0°
9. As cruise airspeed is attained, set cruise power
• Re-trim as necessary
10. Complete the Cruise Flow/Checklist
Power-Off Stalls:
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Airplane Flying Handbook, Power-Off Stall
Power-off stalls simulate a stall during the normal approach to landing
• Should be set up in the landing configuration
Recoveries therefore train a pilot to make prompt, positive, and effective
recoveries with a minimum loss of altitude
This stall may occur while descending in an actual or simulated emergency or in
any power-off situation when airspeed is not controlled
Power-Off Stall & Recovery Procedure:
1. Select an altitude where recovery will occur no lower than 1500' AGL
2. Perform clearing turns
3. Reduce power adjusting pitch to maintain altitude
• Trim as necessary
4. Below VLO, extend the landing gear, as required
• Callout: "Gear Down"
• Verify gear DOWN and callout "3 Green, No Red
5. Below VFE, extend the flaps
6. Advance the propeller control to full forward (high rpm) as required
7. Maintain altitude until reaching a normal approach speed and then
maintain that speed in a stabilized descent
8. Descending no lower than 200', simultaneously reduce power to idle and
pitch up to Vy attitude (4-5 degrees, cowling on the horizon)
• This pitch attitude will be a normal landing attitude
• Above 5 knots, above stall speed the horn will sound
• Stall may be performed level or with up to 20° bank angles
9. At the stall, call out "stalling"
10. Reduce the AoA to regain control
11. Add full power
12. Pitch for Vy
• Glare shield level with the horizon
13. Maintain coordination using rudder to prevent spins
14. With a positive rate of climb established:
• Begin to raise the flaps in 10° increments
• Below VLO, and with a positive rate of climb established, call out
"positive climb, gear up," and retract the landing gear
• Note, some aircraft Pilot Operating Handbooks may require flaps
be partially retracted before a positive rate of climb is possible
15. Complete cruise checklist, returning to the altitude, heading, and airspeed
required
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Power-Off Stall & Recovery Common Errors:
• Failure to adequately clear the area
• Failure to establish the specified landing gear and flap configuration prior
to entry
• Improper pitch, heading, and bank control during straight ahead stalls
• Use outside and instrument references
• Right rudder in nose-high power-on condition; release at break
• Improper pitch and bank control during turning stalls
• Rough or uncoordinated control technique
• Failure to recognize the first indications of a stall
• Failure to achieve a stall
• Improper torque correction
• Poor stall recognition and delayed recovery
• Excessive altitude loss or excessive airspeed during recovery
• Secondary stall during recovery
Power-Off Stall Airman Certification Standards:
• Airman Certification Standards
Cross-Controlled Stalls:
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Cross-control stalls emphasize the importance of using coordinated control
pressures whenever making turns
Most apt to occur during a poorly planned and executed base-to-final approach
turn
Practicing approaches to stalls demonstrates the transition from cruise flight to
critically slow airspeeds in various conditions
Cross-Controlled Stall & Recovery Procedure:
WARNING:
All procedures are GENERALIZED.
Always fly per Pilot Operating Handbook procedures,
observing any relevant Standard Operating Procedures (SOPs)