STALLS: power-on and power-off

Objective:
For student to understand the nature and causes of stalling, to recognize the warning signs, and to recover from a stall. Also, to make student feel at ease with stalling so as to feel comfortable with the maneuver e.g. during the practical test.

Content:
Aerodynamics of stalls. Procedures for entry and recovery of power-on stall. Procedures for entry and recovery of power-off stall.

Equipment:
Airworthy aircraft. PTS. Flight maneuvers illustrator. Model airplane. Whiteboard

Schedule:
Preflight ground school (30 minutes, including power-on and power-off stalls)
Instructor demonstrations (20 minutes)
Student practice (50 minutes)
Postflight feedback (10 minutes)

Instructor:
Preflight: (see lesson plan) motivate, explain, have student be an armchair pilot, list common errors, discuss.
In flight: Demonstrate proper stalling operations while talking through them. Coach and encourage student.
Postflight: Give feedback and suggestions.

Student:
Preflight: Attend to explanation, be an armchair pilot, answer questions
In flight: Perform new maneuvers after demonstration
Postflight: Ask questions.

Completion standards:
Power-off stalls: As per PTS: exhibits knowledge of stall elements, configures aircraft appropriately for approach/landing at entry altitude to allow completion (recovery) above 1,500 AGL, transitions smoothly to stall attitude, maintains specified heading +/- 10 or turn of 30 +0/-10, recognizes and announces onset of the stall and recovers correctly.
Power-on stalls: As per PTS (and above) except now in takeoff configuration, and 20 degrees bank +/- 10.
General: St should be able to explain the procedures and reasons for them.

GROUND LESSON:
Power-on stalls

Review: short-field takeoff


Objective: stall introduction, power-on stall characteristics, inducement and recovery procedures
materials: PTS, flight maneuvers illustrator, model plane, handout

Attention/motivation: (2 minutes)
Ever have your car "stall"? Well, when an airplane stalls, it has nothing to do with the engine. Imagine doing a short-field takeoff. Trying to get over those trees, and… What's going to happen if we keep pulling back?

Overview and Explanation: (6 minutes)
I. What is a stall? Aerodynamics: critical angle of attack (define) exceeded, airflow separates from the upper wing. In practical terms, the wing no longer produces lift. Roots stall first: why?
II. Can this happen if the engine is running full blast? Sure! "This can occur at any airspeed, in any attitude, with any power setting" (AFH pg. 5-2).
III. How to recognize a stall: vision (attitude), sound (engine), kinesthesia, control pressure
IV. How do we get out of it: stay coordinated (define), lower nose, power-up. Secondary stalls.
V. A spin (Define) can be the consequence of being uncoordinated. Step on the ball.
VI. Contributing factors: weight, CG, load factor (bank angle or pitch), configuration
Do imminent stalls first, then full stalls. Stall in arrow:
1. CLEAR AREA.
2. Configure plane for takeoff: usually clean configuration, but gear could be down according to instructor/examiner
3. Mixture rich, props forward, throttle back and maintain altitude until rotation speed.
4. Look around, then assume rotation attitude. (right rudder!)
5. Turn or maintain heading as instructed
6. More back pressure to an attitude "obviously impossible for the airplane to maintain" (AFH, p. 5-7). Stay coordinated!
7. Increase back pressure to maintain high attitude until indications of a stall. Announce them as they come.
8. At imminent or full stall, release back pressure to bring nose down. (stay coordinated) Use rudder to stay level.
9. Add power and recover with minimum loss of altitude but no secondary stall.
10. Checklist

Armchair piloting: (8 minutes)
What is the order of the steps? Do them.

Common errors: (3 minutes)

Not clearing the area
Improper configuration
Losing heading
Not slowing to rotation speed
Must increase back pressure progressively
Uncoordinated (very bad)
Lack of recognition of stall characteristics
Stall not achieved, or excessive altitude loss
Panicking: improper control order/recovery
Secondary stall (unsat.)

Oral evaluation of understanding through discussion/quiz: (2 minutes)
Q: What are the PTS tolerances?
Q: Why do wing roots stall first? Why are planes designed that way?
Q: What is a spin? How do we avoid them?
Q: What is a secondary stall?



GROUND LESSON:
Power-off stalls

Review: short-field approach and landing


Objective: power-off stall characteristics, inducement and recovery procedures
materials: PTS, flight maneuvers illustrator, model plane, handout

Attention/motivation: (2 minutes)
We've discussed a power-on stall. When might a power-off stall happen? Have we tried to stretch out a glide before? Is altitude always going to be controlled by pitch? (Engine-out emergency landing?) What do you think: is it better to stall, or hit trees? THE WORLD ACCORDING TO BYRON: "You fly the plane until the last piece of it stops moving."

Overview and Explanation: (6 minutes)
I. Aerodynamics review: critical angle of attack (define) exceeded, airflow separates from the upper wing. "This can occur at any airspeed, in any attitude, with any power setting."
II. How to recognize a power-off stall: sound may not be a factor any more, vision (attitude), kinesthesia, control pressure
III. How do we get out of it: stay coordinated (review), lower nose, power-up. Secondary stalls.
Do imminent stalls first, then full stalls. Stall in arrow:
1. CLEAR AREA
2. Configure plane for landing: pre-landing checklist and flaps.
3. Throttle back and establish descent.
4. Look around while flaring to maintain altitude with back elevator pressure.
5. Turn or maintain heading as instructed. Stay coordinated!
6. Increase back pressure to maintain high altitude until indications of a stall. Announce them as they come.
7. At imminent or full stall, release back pressure to bring nose down. (stay coordinated)
8. Add power.
9. Flaps-gear-flaps-flaps, and recover with minimum loss of altitude but no secondary stall
10. Establish climb.
11. Checklist

Armchair piloting: (8 minutes)
What is the order of the steps? Do them.

Common errors: (3 minutes)

Not clearing the area
Improper configuration
Losing heading
Must increase back pressure progressively
Uncoordinated (very bad)
Lack of recognition or stall characteristics
Stall not achieved, or excessive altitude loss
Panicking: improper control order/recovery
Secondary stall (unsat.)
Flaps or gear not retracted

Oral evaluation of understanding through discussion/quiz: (2 minutes)
Q: What are the PTS tolerances?
Q: Review: What is a spin? How do we avoid them?