Presentation Copyright © 2015
AvSport of Lock Haven
What’s the Spin on Stalls?
Mastering the most dreaded maneuver in flight training
Prof. H. Paul Shuch, Ph.D., CFII LSRM-A/GL/WSC/PPC, iRMT Heavy
Chief Flight Instructor, Director of Maintenance,AvSport of Lock Haven
FAA Safety Team Lead Representative, Piper Memorial Airport, Lock Haven PA
Presentation Copyright © 2015
AvSport of Lock Haven
What’s the Spin on Stalls?
A FAASTeam Wings Award Safety Webinar
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AvSport of Lock Haven
What’s the Spin on Stalls?
• Experimental Aircraft Association• AvSport of Lock Haven• Aircraft Spruce and Specialty Company• Your FAA Safety Team
Brought to you by:
Presentation Copyright © 2015
AvSport of Lock Haven
What’s the Spin on Stalls?
Stalls are undoubtedly the most feared maneuver in the flight training curriculum. They are also an essential element of every single flight, in that an aircraft cannot land if its wing is still developing lift. In this FAA Safety Team Wings webinar, you'll learn how to love stalling the airplane just inches above the runway, while avoiding that dreaded stall/spin accident.
RATIONALE:
Presentation Copyright © 2015
AvSport of Lock Haven
What’s the Spin on Stalls?
OBJECTIVES
Upon successful completion of this webinar, you will:• Understand and master critical angle of attack• Explain how wings stall at any speed, in any attitude• Practice approach-to-landing stalls to master the flare• Practice power-on stalls to avoid inadvertent spins• Convert a power-on to a power-off stall to aid recovery• Avoid spins by ensuring that both wings stall equally• Demonstrate safe stall and spin recovery procedures
Presentation Copyright © 2015
AvSport of Lock Haven
What’s the Spin on Stalls?
Caveat:• The procedures shown here are used successfully by one
particular instructor, in one particular aircraft. They may not apply in your situation.
Disclaimer:• Nothing in this presentation should be considered a substitute for
adequate dual training, conducted by an appropriately rated flight instructor familiar with your particular aircraft.
Waiver:• By viewing this presentation, you understand and agree that:
– Flying is a sport– There is risk associated with all sports– You accept that risk
Presentation Copyright © 2015
AvSport of Lock Haven
What’s the Spin on Stalls?
Aerodynamics - How the wing lifts
Bernoulli’s Principle:
As the velocity of a fluid increases, its pressure decreases. The accelerated air above the wing exerts less pressure on the wing than the un-accelerated air below it.
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AvSport of Lock Haven
What’s the Spin on Stalls?
Aerodynamics - How the wing lifts
Air flow over the wing creates downwash, the pushing of air down creates a lifting force.
The direct deflection of air downwards off of the lower surface of the wing also creates a resulting lifting force upward.
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AvSport of Lock Haven
What’s the Spin on Stalls?
Stall: automotive definition
• The engine quits under load
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AvSport of Lock Haven
What’s the Spin on Stalls?
Stall: aerodyamic definition
• The wing stops developing lift
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AvSport of Lock Haven
What’s the Spin on Stalls?
Common Stall Myths
• You can’t stall without pulling the nose up
• You only stall when you go too slow
• Stall speed is a constant number
• You won’t stall if you stay above stall speed
• To recover from a stall, you must add power
• Failure to recover from a stall leads to a spin
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AvSport of Lock Haven
What’s the Spin on Stalls?
Anatomy of a Stall
• Cord Line
• Relative Wind
• Angle of Attack
• Airflow Separation
• Recovery
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AvSport of Lock Haven
What’s the Spin on Stalls?
Anatomy of a Stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
Anatomy of a Stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
Critical Angle of Attack Can Be Exceeded In Any Flight Attitude!
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AvSport of Lock Haven
What’s the Spin on Stalls?
Doh!
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AvSport of Lock Haven
What’s the Spin on Stalls?
A stall occurs when:
• The engine quits under load• The airspeed gets too low• Critical Angle of Attack is exceeded• The nose gets too high• A spin develops
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AvSport of Lock Haven
What’s the Spin on Stalls?
“OK, now we’re going to do stalls!”
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AvSport of Lock Haven
What’s the Spin on Stalls?
Three Types of Stall:
• Approach-to-landing stall– often called a Power-Off Stall
• Takeoff and departure stall– often called a Power-On Stall
• Accelerated Stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
The Approach-to-Landing Stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
The Approach-to-Landing Stall
• Power reduction
• Glide established
• Stretching the glide
• Stall recognition
• Stall recovery
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AvSport of Lock Haven
What’s the Spin on Stalls?
Glider and Stall Practice
• Power off stall practice simulates an approach to landing, followed by a flare
• So, the purpose of power off stalls is to learn how to flare properly
• If you don’t stall, you can’t land!• Some pilots believe they can stay safe by never stalling• They’re still up there!
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AvSport of Lock Haven
What’s the Spin on Stalls?
Quiz time!
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AvSport of Lock Haven
What’s the Spin on Stalls?
Power-off stalls are used to simulate
• takeoff rotation• landing flare• slow flight• go-around• touch-and-go
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AvSport of Lock Haven
What’s the Spin on Stalls?
Takeoff and Departure Stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
Takeoff and Departure Stall
• Establishing a climbout
• Over-rotation
• Obstacle clearance
• Stall recognition
• Stall recovery
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AvSport of Lock Haven
What’s the Spin on Stalls?
To go up, pull stick back.
To go down, pull stick way back.
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AvSport of Lock Haven
What’s the Spin on Stalls?
Departure Stall Recovery
• Reduce power
• Reduce angle of attack
• Rudder to keep wings level
• Add climb-out power
• Establish best climb speed
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AvSport of Lock Haven
What’s the Spin on Stalls?
Another Question!
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AvSport of Lock Haven
What’s the Spin on Stalls?
The first step in recovery from a power-on stall should be to
• Level the wings• Lower the nose• Add full power• Convert it to a power-off stall• Pull back on the stick
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AvSport of Lock Haven
What’s the Spin on Stalls?
Accelerated stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
Accelerated stall
• Load factor
• Bank angle
• Abrupt control changes
• Secondary stalls
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AvSport of Lock Haven
What’s the Spin on Stalls?
Accelerated stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
Accelerated stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
Accelerated stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
Secondary stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
I know this one!
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AvSport of Lock Haven
What’s the Spin on Stalls?
An accelerated stall
• Happens at lower than normal airspeed• Occurs only during a steep turn• Is another name for a secondary stall• Can occur with little warning• Results in little altitude loss
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AvSport of Lock Haven
What’s the Spin on Stalls?
Spin Avoidance and Recovery
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AvSport of Lock Haven
What’s the Spin on Stalls?
Spin Avoidance and Recovery
• Torque affects
• Power reduction
• Breaking the stall
• Stopping the rotation
• Flying out of the dive
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AvSport of Lock Haven
What’s the Spin on Stalls?
To go up, pull stick back.
To go down, pull stick way back.
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AvSport of Lock Haven
What’s the Spin on Stalls?
Necessary Conditions for a Spin
• Critical angle of attack exceeded
• One wing stalls first
• Asymmetrical lift
• Aggravated by torque
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AvSport of Lock Haven
What’s the Spin on Stalls?
Overshooting turn to final
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AvSport of Lock Haven
What’s the Spin on Stalls?
Overshooting turn to final
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AvSport of Lock Haven
What’s the Spin on Stalls?
Spin Recovery Technique
• Remove excess torque
• Break the stall
• Stop the rotation
• Level the wings
• Recover from power off stall
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AvSport of Lock Haven
What’s the Spin on Stalls?
Final Question!
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AvSport of Lock Haven
What’s the Spin on Stalls?
A spin can occur when
• You overshoot the turn to final• One wing stalls before the other• The aircraft is cross-controlled• You initiate a go-around without rudder• Any of the above
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AvSport of Lock Haven
What’s the Spin on Stalls?
Final Safety Thoughts
• Practice at an adequate altitude• Ailerons lose effectiveness• Steer with your feet• If all else fails, let go• Don’t spin unless approved in aircraft
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AvSport of Lock Haven
What’s the Spin on Stalls?
Respect All Placards!
Presentation Copyright © 2015
AvSport of Lock Haven
What’s the Spin on Stalls?
Caveat:• The procedures shown here are used successfully by one
particular instructor, in one particular aircraft. They may not apply in your situation.
Disclaimer:• Nothing in this presentation should be considered a substitute for
adequate dual training, conducted by an appropriately rated flight instructor familiar with your particular aircraft.
Waiver:• By viewing this presentation, you understand and agree that:
– Flying is a sport– There is risk associated with all sports– You accept that risk
Presentation Copyright © 2015
AvSport of Lock Haven
What’s the Spin on Stalls?
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