SS

DIEGOALFON@AOL.CODIEGOALFON@AOL.COMMRE: Safety SeminarsRE: Safety Seminars

ConstructiveConstructiveCriticism.Criticism.Flying StoriesFlying StoriesSerious onesSerious ones

ororFunny onesFunny ones

ALL MATERIALS CONTAINED HEREIN ARE THE PROPERTY OF

DIEGO M. ALFONSO SRTHIS MATERIAL IS PROTECTED BY

COPYRIGHT AND MAY NOT BE REPRODUCED OR COMMERCIALLY PRESENTED IN ANY

FORM WITHOUT THE WRITTEN CONSENT OF DIEGO M. ALFONSO SR.

PERSONAL USE MEANS INDIVIDUAL PRIVATE USE. ANY UNAUTHORIZED USE, COPYING, EDITING, EXHIBITION, RENTING, LENDING, PUBLIC PERFORMANCE OR BROADCAST OF THIS MATERIAL IS STRICTLY PROHIBITED.

ANY SUCH UNAUTHORIZED ACTIVITY ESTABLISHES CIVIL LIABILITY AND MAY GIVE

RISE TO A CRIMINAL PROSECUTION.

BYBYDIEGO M. ALFONSO SR.DIEGO M. ALFONSO SR.

STALL/SPINSTALL/SPINPREVENTIONPREVENTION

ANDANDSURVIVALSURVIVAL

THINGS THATTHINGS THATMAY HURT YOUMAY HURT YOU

WHAT WE NEED TOWHAT WE NEED TOKNOWKNOW

BUT HAVEN’TBUT HAVEN’TLEARNED.LEARNED.USUALLYUSUALLY““BASICBASIC

KNOWLEDGE”KNOWLEDGE”

WHAT WE ONCEWHAT WE ONCEKNEW BUT DON’TKNEW BUT DON’TREMEMBER NOW.REMEMBER NOW.

WHAT WE KNOWWHAT WE KNOWAND REMEMBERAND REMEMBER

BUTBUT “ “CAN NOT”CAN NOT”

PROFICIENTLY ANDPROFICIENTLY ANDREADILY EXECUTEREADILY EXECUTE

WHAT WE DON’T KNOWWHAT WE DON’T KNOWBUTBUT

“ “WE THINK”WE THINK”WE DO.WE DO.

GRAY AREASGRAY AREASANDAND

MISCONCEPTIONSMISCONCEPTIONS

SHOW ME A PILOTSHOW ME A PILOTTHAT CAN’T PERFORMTHAT CAN’T PERFORMA GIVEN TASK, & I’LLA GIVEN TASK, & I’LLSHOW YOU A PILOTSHOW YOU A PILOT

THAT DOESN’T THAT DOESN’T ““UNDERSTAND”UNDERSTAND” WHAT WHAT

HE/SHE IS TRYING TO DO.HE/SHE IS TRYING TO DO.TRAINING CONSULTANT

““THE EYE CAN’T SEETHE EYE CAN’T SEE

WHAT THE MINDWHAT THE MIND

DOESN’T KNOW”DOESN’T KNOW”

DR. JUDY WALLDR. JUDY WALL

THIS PRESENTATIONTHIS PRESENTATIONALONEALONE

IS NOT ENOUGHIS NOT ENOUGH

THIS DISCUSSIONTHIS DISCUSSIONIS BASED ONIS BASED ON

SUBSONICSUBSONICAIRCRAFT.AIRCRAFT.

VERY BASIC.VERY BASIC.

WHY UNINTENTIONALLY WHY UNINTENTIONALLY STALL/SPINS OCCURSTALL/SPINS OCCUR

THE TRAININGTHE TRAININGSYNDROMESYNDROME

THE OBJECTIVE OF THE OBJECTIVE OF LEARNING STALLSLEARNING STALLS

HOW MANY OF YOU KNOW?:HOW MANY OF YOU KNOW?:

HOW TO AVOID A STALL?HOW TO AVOID A STALL?HOW TO RECOGNIZE A STALL?HOW TO RECOGNIZE A STALL?

HOW TO RECOVER FROMHOW TO RECOVER FROMA STALL?A STALL?

WHAT IS A STALL?WHAT IS A STALL?WHERE IS A STALL MOSTWHERE IS A STALL MOST

LIKELY TO HAPPEN?LIKELY TO HAPPEN?

WHAT IS THE WHAT IS THE STALL SPEED IN STALL SPEED IN

THE CLEAN THE CLEAN CONFIGURATION, CONFIGURATION,

OF THE OF THE AIRPLANE YOU AIRPLANE YOU

FLY?FLY?

IF YOU PUSH THE STICK IF YOU PUSH THE STICK FORWARD, THE HOUSES FORWARD, THE HOUSES GET BIGGER. IF YOU PULL GET BIGGER. IF YOU PULL THE STICK BACK, THEY THE STICK BACK, THEY GET SMALLER. THAT IS, GET SMALLER. THAT IS, UNLESS YOU KEEP UNLESS YOU KEEP PULLING THE STICK ALL PULLING THE STICK ALL THE WAY BACK, THEN THE WAY BACK, THEN THEY GET BIGGER AGAIN.THEY GET BIGGER AGAIN.

MAINTAIN THY MAINTAIN THY AIRSPEEDAIRSPEED

LEST THE GROUND LEST THE GROUND RAISE UP ANDRAISE UP ANDSMITE THEE.SMITE THEE.

DO NOT EXCEED THYDO NOT EXCEED THYCRITICALCRITICAL

ANGLE OF ATTACKANGLE OF ATTACK

LEST THE GROUNDLEST THE GROUND RAISE UP ANDRAISE UP ANDSMITE THEE.SMITE THEE.

MANEUVERSMANEUVERSNOTNOT

ACCIDENTSACCIDENTS

WHYWHYIS IT AIS IT A

MANEUVER?MANEUVER?

STALLS ARE OURSTALLS ARE OURBEST FRIENDS.BEST FRIENDS.

THE SAFETY VALVETHE SAFETY VALVE

THERE ARE NOTHERE ARE NOIMMINENT STALLSIMMINENT STALLSFOR CHECKRIDESFOR CHECKRIDES

EXCEPT ATPEXCEPT ATP

AFTER STALL OCCURSAFTER STALL OCCURS

AS THE STALL OCCURSAS THE STALL OCCURS

ONLY FULL STALLSONLY FULL STALLS

STALLSTALLSPIN SPIN

AWARENESSAWARENESS

WHAT DOES IT WHAT DOES IT MEANS?MEANS?

HOW DO YOU TRAIN HOW DO YOU TRAIN FOR STALL/SPIN FOR STALL/SPIN AWARENESS?.AWARENESS?.

POWER ON STALLS.POWER ON STALLS.POWER OFF STALLS.POWER OFF STALLS.

CROSS CONTROL STALLS.CROSS CONTROL STALLS.ELEVATOR TRIM STALLS.ELEVATOR TRIM STALLS.

SECONDARY STALLS.SECONDARY STALLS.ACCELERATED STALLS.ACCELERATED STALLS.STRAIGHT/TURNING.STRAIGHT/TURNING.

CLEAN/DIRTY.CLEAN/DIRTY. SPINSSPINS

POWER OFF.POWER OFF.POWER ON.POWER ON.

UNDER THE HOOD.UNDER THE HOOD.

HOW MANYHOW MANYINSTRUMENT RATED INSTRUMENT RATED

PILOTS HAVEPILOTS HAVEPRACTICEPRACTICESTALLSSTALLS

UNDER THE HOOD?UNDER THE HOOD?

THETHEFOUR FOUR

ANGLESANGLES

THERE ARE FOUR DIFFERENT THERE ARE FOUR DIFFERENT ANGLES THAT THE PILOTANGLES THAT THE PILOT

SHOULD BE FAMILIAR WITH.SHOULD BE FAMILIAR WITH.

AIRCRAFT’S RELATIVE ANGLEAIRCRAFT’S RELATIVE ANGLE

ANGLE OF ATTACKANGLE OF ATTACK

AIRCRAFT’S PATH ANGLEAIRCRAFT’S PATH ANGLE

ANGLE OF INCIDENCEANGLE OF INCIDENCE

AIRCRAFT’S AIRCRAFT’S ANGLE OF INCIDENCEANGLE OF INCIDENCE

THE ANGLE BETWEEN THETHE ANGLE BETWEEN THECHORD LINECHORD LINE

OF AN AIRCRAFT AND THE OF AN AIRCRAFT AND THE LONGITUDINAL AXIS. LONGITUDINAL AXIS.

ANGLE OF INCIDENCE

ANGLEOF

INCIDENCE

CHORDLINE

LONGITUDINALAXIS

IT HAS NOTHING TO DO WITH STALLSMOST PILOTS KNOW THIS BUT THEY CAN'T SEE IT.

IT IS SET TO COUNTERACT TORQUE IT IS SET TO COUNTERACT TORQUE EFFECTSEFFECTS

DURING CRUISE.DURING CRUISE.

ANGLE OF ATTACK

THE ANGLE BETWEEN THECHORD LINE

AND THERELATIVE WIND

AIRCRAFT’S ANGLE OF ATTACKAIRCRAFT’S ANGLE OF ATTACKDURING CLIMBDURING CLIMB

CHORDLINE

ANGLEOF

ATTACK

RELATIVE WINDRELATIVE WIND

MOST PILOTS KNOW THISBUT CAN'T VISUALIZE IT.

THE ANGLE BETWEEN:WHERE

THE NOSE IS POINTING(LONGITUDINAL AXIS)

AND WHERETHE AIRPLANE IS GOING.

THE AIRCRAFT’STHE AIRCRAFT’SPATH ANGLEPATH ANGLE

AIRCRAFT’S PATH AIRCRAFT’S PATH ANGLEANGLE

DURING CLIMB.DURING CLIMB.

FLIGHT PATHANGLE

FLIGHT PATHFLIGHT PATH

THE AIRPLANE CLIMBS AND MOVES FORWARD.

MOST PILOTS DON’T UNDERSTAND THIS.

LONGITUDINALAXIS

IT CAN’T BE SEEN EITHER.

AIRCRAFT’S RELATIVE AIRCRAFT’S RELATIVE ANGLEANGLE

THE ANGLE BETWEEN THETHE ANGLE BETWEEN THELONGITUDINAL AXISLONGITUDINAL AXIS

OF AN AIRCRAFT AND THE OF AN AIRCRAFT AND THE EARTH’S NATURAL HORIZON. EARTH’S NATURAL HORIZON.

THE KILLER ANGLETHE KILLER ANGLE

AIRCRAFT’S RELATIVE ANGLE

HORIZONLINE

HORIZONLINE

AIRCRAFT’SRELATIVEANGLE

THE KILLER THE KILLER ANGLEANGLE

LONGITUDINALAXIS

WHAT IS THE AIRCRAFT’S RELATIVE ANGLE WHAT IS THE AIRCRAFT’S RELATIVE ANGLE GOOD FOR?GOOD FOR?ATTITUDE ATTITUDE FLYING.FLYING.

IT HAS NO MEANINGFUL INFORMATION ABOUT STALLS.ALL PILOTS SEE

IT.IS NOT

UNDERSTOOD.THE ANGLE BETWEEN THE LONGITUDINAL THE ANGLE BETWEEN THE LONGITUDINAL

AXISAXIS AND THE EARTH’S NATURAL HORIZON. AND THE EARTH’S NATURAL HORIZON.

AA BB CC

WHICH AIRPLANE HASWHICH AIRPLANE HASTHE HIGHEST ANGEL OF ATTACKTHE HIGHEST ANGEL OF ATTACK

DETERMINING DETERMINING THE STALL THE STALL CONDITIONCONDITION

§ 23.201 Wings level stall.§ 23.201 Wings level stall.

Starting from a speed at Starting from a speed at least 10 knots above the least 10 knots above the stall stall speed, the elevator speed, the elevator control control must be pulled must be pulled back back so so that the rate of speed that the rate of speed reduction reduction will not will not exceed exceed one knot per one knot per second until a second until a stall is stall is produced,as shown produced,as shown by either:by either:

(1) An uncontrollable (1) An uncontrollable downward downward pitching motion ofpitching motion of the airplanethe airplane

(2) A downward pitching motion (2) A downward pitching motion of the airplane resulting from of the airplane resulting from the activation of a stall the activation of a stall

avoidance device (for avoidance device (for example,stick example,stick pusher); pusher);

(3) The control reaching the (3) The control reaching the stop.stop.

(c) V(c) VS1S1 is the stalling speed, is the stalling speed, if obtainable, or the minimum if obtainable, or the minimum steady speed, in knots, CAS at steady speed, in knots, CAS at which the airplane is which the airplane is

controllable with -controllable with -(1)Engine idling,throttle closed(1)Engine idling,throttle closed(2) Propeller takeoff position;(2) Propeller takeoff position;(3) Airplane in the condition (3) Airplane in the condition existing in the test in which existing in the test in which VVS1S1 is being used is being used(4)Maximum weight. (4)Maximum weight.

DEFINITION OF VDEFINITION OF VS1S1

(a) VS0 is the stalling speed, if (a) VS0 is the stalling speed, if obtainable, or the minimum steady obtainable, or the minimum steady speed, speed, in knots (CAS), at which the in knots (CAS), at which the airplane is airplane is controllable, with thecontrollable, with the

1 Power condition set forth in 1 Power condition set forth in subparagraph (c);subparagraph (c);

2 Propeller in the takeoff position2 Propeller in the takeoff position3 Landing gear extended;3 Landing gear extended;4 Wing flaps in the landing position4 Wing flaps in the landing position5 Cowl flaps closed;5 Cowl flaps closed;6 Center of gravity AFT LEGAL LIMIT6 Center of gravity AFT LEGAL LIMIT7 Maximum weight.7 Maximum weight.

DEFINITION OF VDEFINITION OF VSOSO

WHAT HAPPENS

WHEN A WING STALLS?

THE WHOLE WING

DOES NOT STALLS AT

ONCE.

WASHOUT

STALL STRIPS OR SPOILERSSTALL STRIPS OR SPOILERS

STALLSTALLRECOVERYRECOVERY

WHY NOSE WHY NOSE DOWN FIRST DOWN FIRST

THEN THEN POWER?POWER?

NO POWERNO POWER

NO RECOVERYNO RECOVERY

PARTIAL POWERPARTIAL POWER

WHAT HAPPENS WHAT HAPPENS IF YOU DON’T IF YOU DON’T

RECOVERRECOVER

FROM A STALL?FROM A STALL?

POWERPOWERONON

STALLSSTALLS

TAKEOFF STALL- STRAIGHTTAKEOFF STALL- STRAIGHT

DEPARTURE STALL-TURNINGDEPARTURE STALL-TURNING

ARE THERE MORE THAN ONE?ARE THERE MORE THAN ONE?

1010º-20º-25º FLAPS/GEAR DOWNº-20º-25º FLAPS/GEAR DOWN

WHY DO WE PERFORMTAKEOFF STALLS?

WHY DO WE PERFORMDEPARTURE STALLS?

HOW SHOULDPOWER ON STALLS

BE PERFORMED?

FROM CRUISE?

ZOOMING UP

SMALL RELATIVE ANGLE

PA-28R-200 ARROWPA-28R-200 ARROW

VVS1S1 60 KIAS 60 KIAS

VVXX 59 KIAS @ 2,750 # GW 59 KIAS @ 2,750 # GWTO 51 KIAS 2000 #TO 51 KIAS 2000 #

POWERPOWEROFFOFF

STALLSSTALLS

APPROACH CONFIGURATION.APPROACH CONFIGURATION.

LANDING CONFIGURATION.LANDING CONFIGURATION.

ARE THERE MORE THAN ONE?ARE THERE MORE THAN ONE?

CLEAN-PARTIAL FLAPSCLEAN-PARTIAL FLAPSGEAR UP OR DOWNGEAR UP OR DOWN

HOW SHOULDHOW SHOULDAPPROACH AND LANDINGAPPROACH AND LANDINGSTALLS BE PERFORMED?STALLS BE PERFORMED?

WHY AREWHY AREAPPROACH AND LANDINGAPPROACH AND LANDING

STALLS PERFORMED?STALLS PERFORMED?

ENGINE FAILURE?ENGINE FAILURE?

WHICH IS THEWHICH IS THEREALISTIC WAY TO REALISTIC WAY TO

INTENTIONALLY STALLINTENTIONALLY STALLAN AIRPLANE?AN AIRPLANE?

WITH THE SHALLOWESTWITH THE SHALLOWESTRELATIVE ANGLE POSSIBLERELATIVE ANGLE POSSIBLESIMULATING A REALISTICSIMULATING A REALISTIC

SCENARIOSCENARIO

THETHECROSS CONTROLCROSS CONTROL

STALLSTALL

STEP ONESTEP ONETURNINGTURNING

FROM BASE TO FINALFROM BASE TO FINAL3030° BANK° BANK

WHY?WHY?

STEP TWOSTEP TWOOVERSHOOTINGOVERSHOOTING

THE RUNWAY CENTERLINETHE RUNWAY CENTERLINE

WHY?WHY?

STEP THREESTEP THREEPILOT UNDERSTANDS A PILOT UNDERSTANDS A CORRECTION FOR THE CORRECTION FOR THE

OVERSHOOT IS NEEDED.OVERSHOOT IS NEEDED.

STEP FOURSTEP FOURPILOT APPLIES INSIDE RUDDERPILOT APPLIES INSIDE RUDDER

(LEFT RUDDER)(LEFT RUDDER)

WHY?WHY?

STEP FIVESTEP FIVETHE REACTION OF THE AIRPLANE THE REACTION OF THE AIRPLANE

CONFUSES THE PILOT.CONFUSES THE PILOT.

WHY?WHY?

STEP SIXSTEP SIXTHE NOSE DROPSTHE NOSE DROPS

THE OUTSIDE (RIGHT) WING THE OUTSIDE (RIGHT) WING ACCELERATES.ACCELERATES.

THE INSIDE (LEFT) WINGTHE INSIDE (LEFT) WINGDECELERATES.DECELERATES.

STEP SEVENSTEP SEVENOVERBANKING TENDENCYOVERBANKING TENDENCY

COMES INTO PLAY.COMES INTO PLAY.

STEP EIGHTSTEP EIGHTTHE PILOT STARTS TOTHE PILOT STARTS TO

COUNTERACT THE BANKINGCOUNTERACT THE BANKINGBY APPLYING RIGHT AILERON.BY APPLYING RIGHT AILERON.

IT IS NOW WHEN THE CONTROLSIT IS NOW WHEN THE CONTROLS

BEGIN TO GET CROSSED.BEGIN TO GET CROSSED.

STEP NINESTEP NINEADVERSE YAW NOW COMESADVERSE YAW NOW COMES

INTO PLAY, AND PULLS INTO PLAY, AND PULLS THE NOSE EVEN LOWER THE NOSE EVEN LOWER

IN RELATION TO IN RELATION TO THE HORIZON.THE HORIZON.

STEP TENSTEP TENAILERON DEFLECTION AILERON DEFLECTION

CREATES A HIGHER ANGLE OFCREATES A HIGHER ANGLE OFATTACK ON THEATTACK ON THE

LEFT(INSIDE) WING.LEFT(INSIDE) WING.

THE PILOT STARTS TO APPLY BACK THE PILOT STARTS TO APPLY BACK ELEVATOR PRESSURE TRYINGELEVATOR PRESSURE TRYING

TO RAISE THE NOSE, INCREASINGTO RAISE THE NOSE, INCREASINGTHE ANGEL OF ATTACK AND AN THE ANGEL OF ATTACK AND AN

UNINTENTIONAL STALL/SPINUNINTENTIONAL STALL/SPINHAS BEEN CREATED.HAS BEEN CREATED.

STEP ELEVENSTEP ELEVEN

DETERMININGDETERMININGPOSITIVEPOSITIVE

RATE OF CLIMBRATE OF CLIMB

VSIVSI

SLOW FLIGHTSLOW FLIGHT

VSVS

MCAMCA

WHAT’SWHAT’STHE MINIMUM THE MINIMUM CONTROLLABLECONTROLLABLE

AIRSPEEDAIRSPEEDOF YOUR AIRPLANE?OF YOUR AIRPLANE?

SPINAWARENESS

HISTORYHISTORY

1912 WILSON PARKER1912 WILSON PARKERDEVELOPED THE SPINDEVELOPED THE SPIN

AS AN EVASIVE MANEUVER.AS AN EVASIVE MANEUVER.IT WAS USED DURINGIT WAS USED DURING

WORLD WAR I.WORLD WAR I.

FROM WWI THROUGH 1949FROM WWI THROUGH 1949SPINSSPINS

WERE REQUIRED FOR PILOT WERE REQUIRED FOR PILOT CERTIFICATE.CERTIFICATE.

1949 CAA ELIMINATED SPINS FROM1949 CAA ELIMINATED SPINS FROMPILOT CERTIFICATE PILOT CERTIFICATE 1.1. HIGH STALL/SPIN ACCIDENTHIGH STALL/SPIN ACCIDENT

RATE.RATE.2.2. ENCOURAGE MANUFACTURESENCOURAGE MANUFACTURES

TO BUILD SPIN PROOF A/CTO BUILD SPIN PROOF A/C

1991 FAA REQUIRED1991 FAA REQUIREDSTALL/SPINSTALL/SPIN

AWARENESS TRAINING. AWARENESS TRAINING. SEE FAR PART 61.SEE FAR PART 61.

AERODYNAMIC AERODYNAMIC CONDITIONS.CONDITIONS.

FLIGHT SITUATIONS.FLIGHT SITUATIONS.

INSTRUMENT READINGS.INSTRUMENT READINGS.

SPIN/SPIRAL.SPIN/SPIRAL.

•LOAD FACTORS LOAD FACTORS SPIN/SPIRAL. SPIN/SPIRAL.

•SPIN TRAINING SPIN TRAINING RECOMMENDED.RECOMMENDED.

•1/4 TURN @ A TIME.1/4 TURN @ A TIME.

SPIN RECOVERYSPIN RECOVERY

ower offower offilerons neutralilerons neutraludder opposite spinudder opposite spinlevator forwardlevator forwardeutralize controlseutralize controlsake it easyake it easy

PPAARREENNTT

GRAY AREASGRAY AREASRECOVERY WITH AILERONSRECOVERY WITH AILERONS

POWER FIRSTPOWER FIRST

POSITIVE RATE OF CLIMBPOSITIVE RATE OF CLIMB

WHICH WAY WILL IT BRAKE?WHICH WAY WILL IT BRAKE?SKIDDING TURNSKIDDING TURN

VSVSSLIPPING TURNSLIPPING TURN

ASE AME

140

40

60

80

120160180

200

220

240

AIRSPEEDMPH

140

40

60

80

100

120160

180

200

220

240

AIRSPEED

MPH50

100

HOW TOHOW TORECOVER IFRECOVER IF

GAINING ALTITUDE GAINING ALTITUDE DURING A STEEP DURING A STEEP

TURN? TURN?

IF DESCENDINGIF DESCENDING60 60 °° BANK BANK

HOW MANY HOW MANY G ’S?G ’S?

HOW TO RECOVERHOW TO RECOVERIF LOOSING IF LOOSING

ALTITUDE DURINGALTITUDE DURINGA STEEP TURN? A STEEP TURN?

WHY?WHY?

WHEN IN AWHEN IN ADESCENDINGDESCENDING

TURN YOU ARETURN YOU ARENOT PULLING UP,NOT PULLING UP,YOU ARE TIGHTENYOU ARE TIGHTEN

THE TURN.THE TURN.

DON’T EVER GIVE UP