Power-off (Approach) Stalls

OBJECTIVE: To develop the pilot’s ability to recognize an approaching stall by sound, sight, and feel; familiarize the pilot with the conditions that produce power-off stalls; and to develop the habit of taking prompt preventative or corrective action to recover from a stall. 
ELEMENTS
  • Aerodynamics of power-off stalls 
  • Relationship of various factors, such as landing gear and flap 
  • Configuration, weight, center of gravity, load factor, and bank angle to stall speed 
  • Flight situations where unintentional power-off stalls may occur 
  • Entry technique and minimum entry altitude. 
  • Performance of power-off stalls in descending flight (straight or turning) 
  • Coordination of flight controls 
  • Recognition of the first indications of power-off stalls 
  • Recovery technique and minimum recovery altitude 

COMPLETION STANDARDS
  • Exhibits knowledge of the elements related to power-off stalls 
  • Selects an entry altitude that allows the task to be completed no lower than 1,500 feet AGL
  • Establishes a stabilized descent in the approach or landing configuration 
  • Transitions smoothly from the approach or landing attitude to a pitch attitude that will induce a stall 
  • Maintains a specified heading, ±10°, in straight flight; maintains a specified angle of bank not to exceed 20°, ±10°; in turning flight, while inducing the stall 
  • Recognizes and recovers promptly after the stall occurs by simultaneously reducing the angle of attack, increasing power to maximum allowable, and leveling the wings to return to a straight-and-level flight attitude with a minimum loss of altitude appropriate for the airplane 
  • Retracts the flaps to the recommended setting; retracts the landing gear, if retractable, after a positive rate of climb is established 
  • Accelerates to Vx or Vy speed before the final flap retraction; returns to the altitude, heading, and airspeed 
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 and turning stalls 
  • Rough or uncoordinated control procedure 
  • Inability to recognize and announce approaching stall condition 
  • Over-reliance on the airspeed indicator while excluding other cues 
  • Inadequate scanning resulting in an unintentional wing-low condition during entry 
  • Excessive back-elevator pressure resulting in an exaggerated nose-up attitude during entry 
  • Failure to achieve a stall 
  • Premature recovery 
  • Poor stall recognition and delayed recovery 
  • Excessive altitude loss during recovery 
  • Excessive forward-elevator pressure during recovery resulting in negative load on the wings 
  • Excessive airspeed buildup during recovery 
  • Inadequate rudder control 
  • Inadvertent secondary stall during recovery 
  • Failure to take timely action to prevent a full stall during the conduct of imminent stalls 
  • Attempting to maintain level flight during stall entry and recovery 

TRICKS
  • In the set up, use ailerons to hold the wings level and rudder to hold zero rate of turn. 
  • At the stall, neutralize the ailerons and do not use them again until the stall horn is off. 
  • In the straight ahead stall, hold zero rate of turn with rudder pressure (step on the high wing). 
  • In the recovery, make changes in elevator pressure slowly. Once the stall horn ceases, no more forward elevator is necessary. Zero G recoveries are not necessary. 
  • Ask Pilot: What (and why) will the steady-state rudder and aileron inputs be in:
  • MCA, straight 
  • MCA, right turn 
  • MCA, left turn 

THINGS TO REMEMBER
  • Stall exercise: At 3000’ AGL min, have pilot try to stall airplane using power only. Rudder is used to keep wings level, yoke is left alone. 
  • Beware power on stalls with flaps!!! (Spin) (Stall starts at outboard edge of flap instead of wing root; wing twist is typically insufficient in flaps down config.) 
  • Stall is a wing drop, full aft stick, or the nose dropping 
  • Aggressive use of the yoke means an aggressive stall; slower control movements give a gentler stall - let pilot do all slow airspeed work if fearful, gradually going slower or adding more power until able to perform maneuver 
  • Tricks 
  • Be very careful with the first flap retraction. People have been killed here. Do not rush it; do not reach for the flap lever at the expense of precise control of attitude, heading or airspeed. In Cessnas, be very careful not to accidentally select flaps UP vs. flaps 20°; this mistake has resulted in fatal accidents. 
  • Know the go around airspeed and configuration. Failure to do so may and often has resulted in injury or death. 
  • The power-off set-up is from a descent at a normal landing airspeed, it is not a constant altitude entry. 
  • Expect the aircraft to pitch up aggressively when you add full power. Be ready to put in whatever forward elevator pressure is necessary to hold the aircraft at the desired attitude, then TRIM off the pressure.
  • Use NO AILERON IN THE RECOVERY!!! (You spin, you die, any questions?)
  • CFIs: Do NOT allow student to develop habit of using ailerons in stall recovery. While trainer aircraft may tolerate the habit, it can be deadly in high performance aircraft.
  • Have student practice stall recovery intentionally leaving the flaps down. Flap failures do occur and pilots have been killed here. 

STUDY

Power-off Stall Procedure

  • Clearing Turns. 
  • Execute pre-landing checklist, hold the flaps for now. 
  • Choose a visual reference on the horizon; point it out and align the aircraft with it. 
  • Reduce power (or, in complex aircraft, extend landing gear). 
  • Pitch and trim for 0 VSI, hands off. 
  • First notch of flaps (relieves back pressure). 
  • As speed decreases, flaps 2 to relieve back pressure. 
  • As speed decreases, flaps 3 to relieve back pressure. 
  • Continue backpressure at zero rate of climb until ASI reaches 1.2 Vso. 
  • Power to idle (rudder for 0 rate of turn). 
  • Pitch and trim for hands off at 500 fpm descent. 
  • Slowly pitch up towards the stall; usually just to or very slightly above the horizon will do. 
  • Hold the pitch attitude with steadily increasing backpressure. 
  • Announce the stall buffet. 
  • Continue increasing backpressure until either wing drop or nose drop. 
  • Recover with simultaneous release of backpressure, advance throttle to full, and step on the right rudder to maintain 0 rate of turn. 
  • Pitch down until the stall horn silences, then pitch up to climb, at edge of stall horn activation. 
  • At positive rate of climb, retract flaps to manufacturer’s recommended 
  • Pitch to a known go-around attitude; adjust to maintain recommended speed. Climb over obstacles at the recommended speed. 
  • Clear of obstacles, increase airspeed by pitching down slightly, but not so much as to cause negative rate of climb. Retract flaps in stages. Attain Vy prior to final flap retraction!!! 
  • Resume normal climb 
  • Climb checklist