Stalls and Spins

    Many student pilots (and many experienced pilots) have a dread of stalls and spins.  It’s normal to want to avoid an unintentional spin, and we should study just why the FAA has instructors teach the way we do. 

    Decades back, the FAA decided it was better to teach spin awareness and avoidance rather than spins themselves.  However, every private pilot curriculum includes stalls, with and without power, entered from both turning and straight flight.  Let’s take a look at that. 

    Stalls are considered maneuvering flight and must be completed at least 1500 ft. AGL.  (This is a minimum altitude; most aerobatic instructors prefer a higher cushion of air below.)

    The pilot is to establish either a stabilized descent or a takeoff & departure climb.  He/she then:

    “transitions smoothly......to a pitch attitude that will induce a 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 straight-and-level flight attitude with a minimum loss of altitude appropriate for the airplane.

    “Retracts the flaps to the recommended setting after a positive rate of climb is established.

    “Accelerates to Vx or Vy speed before the final flap retraction....”  (all quotes from Practical Test Standards)

    About spins, the PTS says the pilot will exhibit knowledge of:


  1. 1.    Aerodynamic factors related to spins.

  2. 2.    Flight situations where unintentional spins may occur.

  3. 3.    Procedures for recovery from unintentional spins.


    So, what is “knowledge”?  Is it knowledge if a pilot can describe some possible spin scenarios, or is it knowledge if the pilot can authoritatively control the aircraft so that a possible spin entry becomes an easy stall recovery? 


   At the school where I teach, one of the pre-solo maneuvers every student pilot must do is a stall entry which simulates the base-to-final stall-spin scenario, but does it at a safe altitude.  Let’s say we are training in a Cessna 152 or 172:

  1. 1.   So as to recover from the maneuver at at least 3000 AGL, the student simulates the traffic pattern descent: power reduction, partial flap extension, trimming for approach speed. 

  2. 2.    The downwind-to-base turn is made, flaps are extended further, aircraft is trimmed again.

  3. 3.    The base-to-final turn is begun, with rising pitch attitude, and the student is encouraged to use rudder in the direction of the turn while preventing the bank angle from getting too steep (i.e., cross-control).

  4. 4.    When the stall occurs, rather abrupt yawing and roll can happen.  Sometimes the airplane will do a sort of “slurve”, wallowing around in the air, and sometimes it will roll and yaw right toward a spin entry. 

  5. 5.    The recovery includes: (Per the POH)








      

    A spin entry from the base-to-final stall never fails to get the full attention of the student.  When it happens, the plane will feel like it is going over inverted, and good rudder control and attitude recovery techniques are needed.  Part of the problem of teaching this is that we can’t guarantee a “snappy” response to these control inputs.  These airplanes like to fly, and will recover from sloppy flying if you just turn loose of the controls, and then recover from the dive or spiral that results.  But, that’s not the desired teaching outcome.  We need to understand spin entries and spins and recoveries from fully developed spins.

    This is why I think the FAA should have us teach more than we are required to about stall and spins.

     The most basic aerodynamic rule is this: A spin is a stalled condition of flight.  No stall, no spin.  In a spin entry, if the angle of attack is reduced below the critical angle of attack, the airplane may enter a spiral dive, but it is no longer a spin entry.  So in many ways, learning stall awareness and stall recoveries and avoiding spins or spin entries is a good thing. 

    But if a pilot has never experienced a spin, and enters a spin inadvertently, how will he/she react?  The world is whirling around, the airspeed indicator reads 0, the stall horn is blowing, the nose of the plane is pointing toward the ground, and pushing the elevator control forward is not intuitive.  In a fully developed spin in a 152, opposite rudder does nothing to stop the rotation.  The pilot must push the elevator control forward, or the plane will not recover from the spin.  

    So, let’s develop a curriculum.  Practice stalls in both straight and turning flight, with and without power on.  Practice the takeoff and departure stall (at a safe altitude) without touching the rudder until the stall break.  (Close throttle, opposite rudder to rotation, reduce angle of attack.)  Let’s practice the base-to-final turn stall with crossed controls.  (Throttle closed, flaps 10°, rudder opposite to rotation, reduce angle of attack, level wings, power full, climb at VX.)  You don’t have to do a fully developed spin to develop the recovery technique.

When you practice a straight stall, see how little altitude loss is needed with a smooth recovery.  A few years ago, I had the pleasure of meeting Mike Lozano, an Atlanta-area CAP member and FAA inspector.  He demonstrated a power-off full stall in a Cessna 182 with three people on board with zero altitude loss.  It can be done.  The recovery must be executed promptly and smoothly, without allowing the nose of the aircraft to drop abruptly.     

Is the FAA correct to teach us to avoid spins by avoiding conditions that can lead to a spin, while flying airplanes that may or may not have tricky spin characteristics?  It’s an ongoing debate, but I have felt for a long time that we should explore spins or at least get ourselves accustomed to recovering from cross-controlled stalls, so that we have the practiced skills to overcome a possible loss of control of the airplane.  Many airplanes are not certificated for spins, and many airplanes cannot be spun safely, but the ones that are “legal” can be great teaching tools for us to add to our skills.

  

    Let me extend thanks here to Catherine Cavagnaro, who runs Sewannee Aerobatic School at KUOS airport, for a day of spin training on the ground and in “Wilbur” the 152 Aerobat.  She also read through a version of this article and made helpful comments about it.  Additional thanks to Mark Winton, owner of Hixson Aviation, retired F-16 pilot, and encourager of spin and unusual attitude recovery training for all of Hixson’s flight students.  Any errors or omissions are mine.


    Addendum, 18 Jan 2012: here is a Flying magazine article on unrecoverable spins: http://www.flyingmag.com/safety/accident-investigations/unrecoverable-spins




1.Retard throttle to idle position

2.Place ailerons in neutral position

3.Apply and hold full rudder opposite to the direction of rotation

4.Just after the rudder reaches the stop move the control wheel briskly forward far enough to break the stall

5.Hold these control inputs until the rotation stops

6.As rotation stops, neutralize rudder and make a smooth recovery from the resulting dive