Recommendation; ...Categories of Aircraft; ...Definitions; ...History of Spins; ...The Airplanes; ...Spin Training; Teaching of Spins; ….Spin Accidents; ...Preliminary Instruction; ...Spin Causes; ...Stages of the Spin; ...Spins in Brief; ...Spin Structure; ...Unintentional Spin Entry Situations; ....Avoiding the Base to Final Spin;
....Things to Know about Spins; …Spins out of a Skid; ...Spin from Downwind Turn Entry; …Spins out of Slips; ...Spin Entry; ...Recovery; …Spin Rebuttal: ...Spin Types; ...The Unrecoverable/uncontrollable Spin; ...Other Recoveries;...Generic Spin Recovery; ...If You don't Use Procedures Recommended; ...Historic Spin Requirements; ...Current Spin Requirements; ...Endorsements (Instructor); ...Spin References; ...Spins Revisited; ...Yaw Required to Spin; ....Spin Statistics; ...The Facts; ...1987 Statistics; ....Expert Opinion; ...AOPA Study; ...The New AOPA Study; ...General Aviation Pilot Stall Awareness Training Study; ...Spin-Statistics; ....Flying with Instructors Can Be Dangerous; ...Instructional Background; ...NTSB Aerobatics Accidents; ...NTSB's Analysis; ...Stowell’s Hypothesis; ... POH Stall Altitude Losses; ...Real-life Conditions; ...Stall vs Spin; ...Protecting Yourself from Stall/Spin Accidents; ...Required Knowledge about Stalls and Spins; ...Knowing Stalls; ...Knowing Spins; ...Stepping on the Sky; In Charge of the Spin; ...A Spin Virgin No More; ...
Every pilot should plan to finance at least five hours or even ten hours of aerobatic flight instruction. This should be from a full-time aerobatics instructor. Flying upside-down will make you a better right-side-up pilot. It is here that you learn to apply forward pressure when inverted to go up.
You have read that an airplane can be stalled from any attitude and at any speed. Doing aerobatics gives you an opportunity to turn the theory into practice. Spin training can be taught safely if the altitudes and maneuvers are planned for safety. Those against spin training desire that stall prevention and recognition are the way to go.
Categories of Aircraft
Normal category aircraft are placarded against spins but they are factory/FAA tested to one turn (or three seconds) with a one-turn recovery when controls are used correctly. Speeds and load factors are not to be exceeded. Flaps may be retracted. No uncontrollable spins are possible in this category. No acrobatics or spins allowed. The weight and CG certification of the aircraft will determine its spin characteristics and recovery procedures. Beyond one turn even correct control input may not work.
Recovery at any time in one turn Tested to six (6) turns clean and one (1) turn w/flaps Speeds and load factors not to be exceeded. Uncontrollable spins are not possible. Entry speeds listed for all maneuvers. The weight and CG certification of the aircraft will determine its spin ability and recovery ability.
Meets either of above requirements FAR Section 23.1567 (New types of airplanes) Pilot to assume aircraft placarded against spins may become uncontrollable in a spin. The weight and CG certification of the aircraft will determine its spin and recovery procedures.
Limited aerobatic maneuvers may be conducted in aircraft that are not certified in the aerobatic category. Some normal category aircraft when operated within the utility category of their weight and balance envelope are permitted to perform those maneuvers listed in placards or the POH.
SPIN An established spin is an aggravated stall that has developed auto-rotational forces. Gravity causes a helical path during the descent. The aerodynamic and inertial forces are balanced. You must upset this balance to recover. The stall, which has directional control, occurs at an angle of attack near 17 degrees. In a spin the down wing may have an angle of attack of 70-80 degrees while the up wing will be between 30 and 40 degrees. The stall prelude to the spin lacks directional control (rudder).
TAIL LENGTH This is the distance from the Center of gravity to the hinges of the tail surfaces. The longer the distance the more nose down the spin and the easier the recovery. An improperly loaded aircraft with a short tail length will spin flat and can be unrecoverable.
STALL Loss of lift and increase in drag that occurs when at angle of attack greater than angle of maximum lift.
SECONDARY STALL Stall that occurs if recovery from initial stall is inappropriately performed usually by excessive elevator.
STALL SPEED Speed at which the critical angle of the relative wind is exceeded. Stall speed decreases with aircraft weight, turbulence, bank angle, abrupt control movement, or any interference with airflow over the lifting surfaces (ice)
ANGLE OF ATTACK Angle the wing chord line has when it meets the relative wind.
CRITICAL ANGLE OF ATTACK Will always result in a stall. The flow of air cannot follow the curve of the wing. For a given flying surface the critical angle of attack never changes. The airspeed at which a flying surface will stall depends on aircraft weight, balance, and load factor.
RELATIVE WIND Speed and direction of wind causes by the aircraft movement. Velocity of relative wind is equal but opposite to speed of aircraft.
COEFFICIENT OF LIFT, (Cl) Factor giving lift created by an angle of attack at a given airspeed.
COEFFICIENT OF DRAG, (Cd) Factor giving drag created by a an angle of attack at a given airspeed.
FLAPS Flaps are lift/drag devices that lower the stall speed. The lift effect is greater than the drag. Flaps make the glide slope more steep for better aim to the landing site. Vso stall speed in the landing configuration.
Vsi Stall speed in a specific configuration.
Va Maneuvering speed at which the airplane will not fold, crumble or mutilate if stalled. No guarantee if stalled above Va.
LOAD FACTOR Is ratio of available lift to total weight. Load factors can be increased by steep turns, abrupt control movement, and turbulence. In level flight the load factor is one. In a 30° bank the factor becomes 1.15, at 45° bank it becomes 1.40, at 60° bank it becomes 2.00, at 70° bank it becomes 3.00, and at 80° bank it becomes 6.00.
CENTER OF GRAVITY CG has indirect effect on angle of attack and the control forces required on the elevators. The CG does affect the aircraft stability and spin recovery. With an aft CG very light control forces could cause a stall from which the available elevator power could not lower the nose for recovery.
WEIGHT The greater the weight the higher the stall speed. The AFM/POH give approach speeds based on allowable gross. At less than gross weights lower approach speeds are allowable. For intentional spins the actual weights must be computed. A rule of thumb is that a 2% increase in weight will cause a 1% change in stall speed.
DENSITY ALTITUDE High altitude and temperature give higher true airspeeds. Since stalls occur at indicated speeds as per the AFM/POH density altitude is not a factor.
TURBULENCE At approach speeds turbulence may cause stalls by changing angle of attack. At cruise fly above stall but less than maneuvering speed.
TRIM Trim is the pilot's pitch management tool which decreases the effect of distractions.
History of Spins
A test pilot, Wilfred Parke, was in a Roe Avro while making a spiraling descent. He inadvertently entered a spin when he failed to remove bank while applying backpressure. Parke made several power and control changes without effect. Parke finally applied and held opposite rudder. The aircraft recovered from the spin and entered a dive. An aviation first.
A few months later he was killed, after engine failure, while turning back to the runway. Apparently, knowing how to recover from a spin is of no avail if you are not aware of the conditions and initiating factors for spins.
Without altitude a recovery in time may not be possible.
SPINS WERE A ONE TIME THING IN 1914
An unheralded aviation pioneer is British scientist, F. A. Lindemann. "The Prof", as he was known, led a very checkered scientific and social career from early WWI through WWII. He was an "idea man" and advisor to Churchill for thirty years. He was a social butterfly and a scientific gadfly to more capable scientists. However, his place in history could well lie in aviation. You never heard of him?
Born of German/American parents, he spoke heavily accented mumbled English. He knew all the "right" British nobility and used their influence to gain both position and prestige. In 1914 he attempted, but failed because of eyesight, to join the Royal Flying Corps. He then used influence to join the scientific staff of the Royal Aircraft Factory.
Lindemann initiated a study of the instrument readings and pilot procedures that seemed to cause the stall/spins occurring during turns. A letter to his father stated, "Nobody can make out quite what happened." Lindemann could find no apparent pattern as to when a stall or a resulting spin might occur. Once an aircraft was in a spin there was no way out of it. The spin turns would increase in speed until the ultimate crash. All flight instructors warned, "Get into a spin; get killed".
The "spin" was the most dreaded unintentional flight occurrence, which resulted in accidents. More to be feared than the more frequent landing accidents. At least, landing accidents could be explained. Lindemann now had an explanation, a theory, about spins.
While never publishing his study results, Lindemann gave many oral accounts of his findings. The spin frequently occurred when the aircraft stalled in other than an absolutely level condition. If one wing dropped any effort to raise it would cause the other wing to flip over the other direction uncontrollably. Even at high speeds, a tight turn might cause one wing to flip over and cause a spin. He insisted that further study to prove the theory required that scientists fly.
Without any flight skills, Lindemann had worked out in theory the probable forces, which caused and existed in a spin. He also figured out, in theory, the control movements required to counteract these forces. His study showed that any instinctive response would not work. The rudder must be held fully against the spin while the nose was kept pointed toward the ground. You could not pull back on the stick until the spin stopped and flying speed was gained. His theory also seemed to indicate that during the recovery the wings of the plane could be pulled off. The way Lindemann used to test his theories was somewhat akin to a medical researcher doing a self-inoculation for a deadly disease. He worked through and around the bureaucracy, used influence, memorized the eye chart for his "blind" eye and learned to fly "poorly". One flight of uncertain date in 1914 justifies Lindemann's place in history.
On this Fall day, he discussed his theories on spin recovery and the planned experiment with selected observers at Farnborough aerodrome. He told them he would deliberately do a stall spin. He certainly must have said his good-byes. He would be using a B.E.2 aircraft of most uncertain flight characteristics. He departed and climbed for many minutes. Far below, the observers saw him reach what must have been the B.E 2's service ceiling of 14,000 feet. They saw the spin well before they heard the cessation of engine noise.
Lindemann now began to test his theory. He pulled the power, slowed the plane and entered into a stall. He held the stall until the left wing dipped and the right wing flipped up for the spin entry. A deliberate entry into a maneuver from which no one had previously recovered and few had survived. A maximum test of accountability and courage.
The fragile airframe was held together by a maze of wires and struts that maximized a power off vertical speed of about 90 mph. Lindemann held the spin, intentionally or otherwise, until it was fully established and then he initiated his unique recovery. A planned application of control forces never before applied. He put in full opposite rudder. Nothing happened. He waited. Still nothing happened. He applied forward control pressure.
He had already fallen thousands of feet with no control effect discernible. Was his theory going to fail at this critical moment? But the rudder was starting to have an effect. The spin was slowing and finally stopped. From the vertical, but without the spin Lindemann now had to complete a recovery. Survival demanded that the pull out would not remove the wings from the fuselage. Slowly, carefully the nose rose and as it rose the aircraft slowed thus easing the stress on its components. The first intentional spin and recovery. All that and survival. Enough?
One such experiment and proof would have satisfied most people, but not Lindemann. He climbed back up to altitude and did the spin and recovery in the other direction. A theory twice applied and proven to be a life saver. From that day on, a pilot's education has not been deemed complete without spin training. (Except, of course, in the U.S. by the FAA)
The British had a military secret. It combined two of the very best qualities of military combat. Deception and skill'. Imagine their chagrin when the British plane would level out close to the ground and scoot to safety. Indeed, the spin was often used in WWI as a deliberate escape maneuver. It wasn't long before the Germans discovered the deception and began to follow spinning planes all the way to the ground. It is not known how the Germans gained the secret of spin recovery. Pilots like to talk flying with other pilots.
Most great aircraft flights recorded in aviation history are about distances, speeds and kills. Why not a special "save" category for Lineman along with Immelman? But again, wouldn't your entering his name into your memory and applying his theory and practice to your own "Lindemann" spin recovery be sufficient.
Normal category aircraft that are placarded against spins must be considered as being non-recoverable from spins. Certification today does not include ability to recover from a fully developed stabilized spin. The required one turn recovery is only the incipient stage of the spin. Aerobatic aircraft have not been tested beyond six turns.
There are legitimate concerns as to just how effective having an aircraft placarded against spins will be in preventing distraction caused spins. Aircraft design, pilot knowledge, enforced training standards, and pilot proficiency are historic causes and corrective factors.
The design of an aircraft rudder section that remains clear of the shielded air that occurs over the horizontal stabilizer and elevator makes for positive spin recoveries. If the empennage extends below the tail if gives a preferred nose down spin. The intent of the T-tail was to provide this desirable clearance but it sacrificed pre-stall buffet. Horizontal stabilizer fillets and a long dorsal fin improve recovery characteristics. One two-place trainer may not recover if loaded over over-maximum gross weight.
Some four-place aircraft rotate so rapidly that the rudder cannot stop it. Requires a parachute. Other aircraft the recovery is too quick when the ailerons are turned into the yaw direction. The resulting secondary stall precipitates a spin in the other direction. The full, abrupt forward elevator control can create an inverted flat spin. There is no place where a pilot can find the names of the aircraft involved.
The normal category of aircraft is certified for a one-turn spin followed by normal recovery. One turn is still in the incipient phase with weak rotational forces and un-stabilized condition. Spinning an aircraft placarded against spins means the pilot is aware that any spin may be uncontrollable and unrecoverable. There are those who would blame the stall/spin accident prior to 1949 on aircraft design. There are those who would say the problem is lack of training, since in that 1949 period solo in less than ten hours was very common.
The Department of Commerce in 1926 had airworthiness requirements for an aircraft to be recoverable from a spin. Ten years later the manufacturers were expected to include standard procedures for spin recovery. To obtain a private or commercial license an applicant was expected to be proficient in precision spin recoveries. About 1950 the government made a major change by requiring stall awareness instead of spin recovery. Flight instruction was required to include power-on/off stall recoveries from normal flight conditions.
Since a spin cannot occur without its initiating stall, it was thought that recognition and recovery along with manufacturing improvements would lower the stall/spin accident rate. Spins were required only from flight instructor applicants. In the late '80s the accelerated stall was removed as a test requirement. In the mid-nineties full stalls have been eliminated. Stall recognition is now the prime requirement.
The government, not recognizing that the average age of an aircraft is now over twenty-nine years, has presumed that improved airworthiness requirements for spin resistance has eliminated all stall requirements beyond recognition of the stall and situations leading to the stall. Any pilot who learns to fly in a Part 23 certified aircraft is likely to become a statistic if caught flying an aircraft certified prior to Part 23 certification.
The essence of spin instruction is not entering the spin or even to make a recovery. It is that you become aware of those situations and conditions that are conducive to the initiation of spins. Avoidance is the key. The untrained pilot will always try to recover with incorrect control input.
Fatalities are not from intentional spins, but from those where an accidental stall leads to a spin. Safety is a matter of choice. As a pilot you have a choice in the avoidance of controllable risk factors. The more competent pilot is more likely to choose a path of lower risk.
The student must first become acquainted with full power-off stalls maintained with yoke all the way back and up while rudder is used to pick-up any wing drop. Rudder turns may be practiced. Next the power-on stalls much the same way but rudder applications must be more in anticipation of any drop. Should a break occur, let the wing get well down before initiating the recovery from the incipient spin.
When you are ready for the spin just continue to hold the yoke back during the 'break'. If you relax during the break you may enter a spiral. Always get the power off and the flaps up when in a spin.
It is most likely that any decrease in the stall/spin accident rate has nothing to do with whether or not spins are being taught in training. Figures show that nearly 50% of aircraft accidents were caused by the stall spin. Now such accidents are a little more than 10% blamed on the stall spin. The stall/spin accident rate of pre-1949 aircraft remains over 40%. Having an instructor aboard is not assurance that a stall/spin accident will not occur even in modern aircraft.
12% of small plane accidents result from spins and comprise 25% of the fatalities. 20% of spin accidents had an instructor aboard. 95% of the stall-spin accidents are initiated below pattern altitude. Some aircraft, training procedures, and decision-making training contribute to these statistics. Descending turns from downwind to base and base to final are the most likely encounter points. A relatively high power setting or an increase in power during these turns will make the aircraft easier to stall/spin because of the increased airflow over the tail surfaces. In these turns only a small amount of rudder is required to initiate the spin. Full elevator is not required and any buffet may not be detected. No recovery with flaps was successful.
The only recovery that has a chance is full reversal of the rudder application. Any use of the elevator or ailerons will be counter productive. The more flaps the greater the tail download due to airflow; this causes the aircraft to pitch up without the usual stall warnings. The sequence of control inputs is first in importance but this is closely followed by the timing of control input. The awareness, recognition and prevention of stalls are essential at low altitudes since the spin is not likely to be recoverable. The initial entry into this situation is caused by a distraction. The NTSB says that 40% of these accidents are initiated by a distraction. To get this statistic they must have been talking to a goodly proportion of dead pilots.
Pattern distractions are of several types. The most likely will be some form of radio communication. In cockpit distractions come next. The implied or real presence of other aircraft even if seen peripherally can result in instinctive control inputs conductive to the stall spin.
The avoidance of distraction requires some emotional and intellectual control. The pilot workload is heavy. The addition of a distraction can be the final straw that takes the pilot's mind off the flying of the plane. Out the window go all the planning and the checklist. The distraction becomes the focus of attention to the elimination of everything else. This only has to happen long enough for the initiation of an unrecoverable spin. I have found the best way to minimize the influence of distraction is to create as many as possible. Actual or created makes no difference, just expose the trainee to as many as possible.
No amount of training in spin recognition or recovery will be effective for the low altitude stall spin. Only training in maintaining the angle of attack, bank angle, and airspeed can be effective. More importantly the training program must rely on the development of judgment. The best decisions a pilot can make regarding the pattern size, making the base turn, adjusting the base leg, turning final just right for runway alignment, making approach adjustments of flaps, power and airspeed, entering the flare and holding on to the touchdown are all a matter of good judgment. It's all a matter of judgment training. Do it right and the presence of a distraction becomes a non-factor. Remove the distractions and you abolish the stall/spin and the accident.
In the process of building judgment I structure my lessons to expose the student to adverse situations likely to be encountered. The use of trim, yoke and power is an art. Every flight situation can be varies by an infinite combination of each. I try to reduce the options by having the student set as many constants and use only one variable at a time. I emphasize constant power until the landing configuration is established. Then power becomes a variable. I want to minimize the workload by setting constants where possible.
--No spin without a stall.
--Aggravated stall gives spin.
--Wing with greater angle of attack stalls, drops while nose yaws.
--Descent is helical (like a coiled spring)
--Only in approved aircraft
--Begin with stall practice
--Spin avoidance from stalls and slow flight by making immediate recovery
--Incipient spin recovery with immediate use of rudder and lowering angle of attack
--Configure for power on/off stalls
--Rudder at stall
Release control pressure, opposite rudder, forward elevator pressure
Turning with excessive/insufficient rudder
Instrument readings become unreliable
Immediate recovery or enter spin
Skidding turn spin direction goes with controls
Slipping turn spin opposite to aileron
(L-R reading on turn coordinator is best indicator.)
The Stages of the Spin:
1. The stall
4. Inverted flat
Any one of the stages can lead to any of the subsequent levels.
Spins in Brief
Stalls do not cause spins. Once a stall occurs and the pilot misuses rudder, aileron, or power individually or in combination auto rotation occurs from the resulting asymmetrical stall and a sideslip.
There is an abrupt loss of control when leaving the stall and entering the spin. The untrained pilot will always react instinctively and apply controls incorrectly thus aggravating the spin entry.
An incipient phase occurs when the foregoing stall is accompanied by uncoordinated yawing. The yaw induces a roll due to increased asymmetric lift on the wing opposite to the applied rudder. The aerodynamic differences from uncoordinated stalled flight causes the nose to drop.
In a spin both wings may be stalled but the one on the outside of the spin has a higher speed and a slightly lower AOA than the inside wing. It is this difference in the two wings AOA and its companion induced drag that causes the turning of the aircraft.
The autorotation to follow is quite varied as long as the dynamic and inertial forces are unbalanced. Airspeed will be changing but the faster the entry the longer it takes to stabilize the spin. By the second turn we may be in a developed (stabilized) spin. IAS will be pegged a few miles above 1G stall speed. Descent will vary but can reach 7500' fpm.
If the center of gravity of the aircraft is aft, with any adverse control application can lead to an unrecoverable flat spin. The 'blanking' of the vertical tail surfaces by a low mounted horizontal tail can prevent the
rudder from becoming effective against the spin. Aircraft tend to recover quickly if the power is off and controls moved to neutral.
Spins have three phases:
Know how to recognize the beginning of a spin. Quickly apply the proper control input. Get out of the incipient spin before it has a chance to develop. In a developed spin an aircraft prohibited for spins may be unrecoverable. To prevent this from occurring, the recognition and recovery from an incipient spin is a desirable training goal. The first turn of a spin causes the greatest loss of altitude, as much as 800' to 1000'. High-density altitude causes faster rate of spin and greater loss of altitude.
Recovery: Immediately, power off, opposite rudder, forward on yoke always in this sequence. If rudder is effective yoke forward may not be necessary. Otherwise, hold full application of controls until recovery. Check turn coordinator for direction if in doubt. The proper recovery from the incipient spin must be initiated at once or the yaw rate will become faster and the nose more toward the vertical.
Spins are fully developed after four turns. Spins are low stress maneuvers for airplanes. When the incipient state stabilizes the dynamic and inertial forces become balanced. They become both equal and opposite. The turn rate, airspeed and vertical speed are constant. Some engines quit during spins. The engine of a C-150 may quit after 8 turns due to unporting of fuel tanks. A 152 takes 12 turns. The size of the rudder determines efficiency of spin recovery. Power makes the spin faster, flatter and makes recovery take longer.
Recovery: The developed phase of the developed spin has two possible outcomes.
a. The recovery, from which the ensuing dive can pull a wing off. Be gentle.
b. The crunch.
(No recovery is possible of a flat spin with rotation about center of gravity except by moving C. G. forward.) Undo your harness and get on windshield panel.
Unintentional Spin Entry Situations
Some of the following situations are pilot/instructor created. The pilot who does not trim for each stabilized flight situation may react to distraction by misapplication of the controls. The pilot who does not fly the airport pattern to maintain a size and shape commensurate to wind conditions is creating a stall/spin situation. The pilot who fails to make flying the aircraft the first priority is looking for a stall spin accident.
I have often contended that the pilot or instructor who does a high percentage of his landing practice at one airport is greatly reducing the opportunity to develop judgment skills in pattern operations. A student needs to rely on a developed skill and judgment for flying a pattern without reliance on geographic terrain indicators. I make a practice of having students 'read' the windsock before getting into the aircraft. The 'read' is always compared to the ATIS or AWOS. As 'reading' skills improve the student can make 'readings' from the air so that patterns are sized to wind conditions. Ground 'walk-throughs' clarify the how, why, when, what, and where for pattern adjustments.
Things to Know about Spins:
--Spin training has not proven effective in preventing or even decreasing the statistical numbers related to stall/spin accidents.
--Over the years, spins have been responsible for about 12% of the accidents and one-fourth of the fatalities.
--Only 5% of all stall/spin accident occurrences happen at altitudes where a recovery would be possible.
--Over 40% of the accidents affecting aircraft certified prior to 1945 are stall/spin accidents.
--Thousands of unreported recoveries from unanticipated spins occur for every spin accident.
-- The lowering of the stall/spin accident rate is more due to improved aircraft design than any regulation or training.
-- 40% of unintentional stall/spin accidents are caused by pilot distraction when buzzing' at low altitude. Positive full elevator ........forward is your best chance of recovery.
--The stall/spin accident rate would increase if spin training were required.
--Human error causes 95% of all stall/spin accidents. The untrained pilot will always apply the controls incorrectly.
--73% of stall/spin accidents result in fatalities.
--Nearly one out of three stall/spin accidents now involve homebuilt aircraft.
--20% of stall/spin accidents result when the pilot perceives a problem and becomes distracted.
Spin Out of a Skid
The spin from a skid can be entered from a left turn in a shallow bank. Pull the power and slow as though making a power-off stall. Just before the stall put in full bottom rudder. This tightens the turn much as might happen in the downwind base to final turn to a runway. The wing will drop and you should apply full right aileron. Recovery from the spin is normal.
Avoiding the Base to Final Spin.
--Short and easy out is to level the wings and execute a go-around
--Continue the turn, make a teardrop back to the centerline. Keep a
constant-angle bank and airspeed.
Use power to control your altitude during the turn. ,
--Increase the angle of bank to tighten the turn. Use coordinated controls with attention to keeping the ball centered for every change in bank. You won’t spin unless yaw occurs. Release rudder pressure once a bank has been reached. Increased bank increases stall speed. Lower the nose accordingly regardless of ground proximity. Being close to the ground is not a problem unless you hit it. Use power as necessary. Do not attempt to increase your bank angle with rudder first. If you don’t like a steep turn close to the ground don’t do it.
--The illusion of making the turn quicker with use of rudder is increased by its ability to lower the nose...Close proximity to the ground will cause the nose lowering to trigger the instinctive reaction of pulling back on the yoke. This will not stop the skid but will decrease you airspeed. The angle of attack will increase and any yaw caused by the rudder creates a spin. Recovery totally depends on having sufficient altitude.
By picking an imaginary airport at least five thousand feet AGL and pretending to make a downwind base to final turn in the above manner, you will get a spin that will quickly take you below your imaginary ground level.
Spin Out of a Slip
A spin out of a slip is a "spin over the top". You must to force it into the spin. Enter a steep climbing turn to the left until you stall. Keep the power on. When the stall breaks and the high wing begins to drop hold the yoke all the way back and up while putting in full top rudder. Hold the controls to the stops while the airplane rolls inverted and the nose will drop down into the spin. Recovery is normal.
Teach spins by entry in a stall aggravated by a skid.
At stall, full rudder, full back elevator
At full turn recover never reaching Vne
The smoothest positive spin entry is when rudder is applied just above the normal stall entry speed. The yoke must be held full back and up. Power can help avoid a spiral and create a positive spin entry but should be off after entry. A spin occurs when directional control is lost in a stalled condition. At or near the stall, the opposite to rudder and aileron rolls and yaws the aircraft into the spin. Thus we precipitate a spin by purposely doing a stall from uncoordinated flight.
Skid: Too much rudder and not enough aileron.
Slip: Too much aileron and not enough rudder.
If you have too much right rudder, in a bank to the right that's a skid. Too little right rudder or any left rudder gives a slip. Generally, any slip will require opposite stick and rudder.
A spin can be entered from a skidding turn. Excessive "inside" rudder causes the ball to move towards the outside of the turn. Another entry to a spin is from a wings-level condition. To do this you use heavy rudder to cause yawing while holding full back and up yoke. The position of the ball will always be to the outside in a spin. It moves to the outside regardless of spin direction. Spins have both roll and yaw.
The standard spin entry and recovery of a one turn spin begins by making a straight ahead stall, put in full rudder, after one turn put in opposite rudder and forward yoke to break the stall. Recover from the dive quickly before the speed increases. Moving the stick forward without reversing the rudder input puts you into an accelerated stall. Putting the yoke forward will increase the rotation speed.
The hands off recovery requires that you release the yoke but hold the rudder. The yoke will remain full back. Apply full opposite rudder and when the spin stops the yoke will move forward and break the stall without the pilot's input.
Flaps up (not mentioned by FAA)
Opposite rudder until rotation slows
Positive forward elevator to break stall.
Neutral rudder and return to level (climb)
All spin recovery methods presume the aircraft is within utility category weight and balance. Prior to attempting recovery the throttle should be retarded, the flaps removed and the ailerons neutralized. Since the rudder yaw began the spin it is the usual main course of action for recovery. Full opposite rudder is the primary first move made very quickly to full deflection. Slow applications will delay recovery. Depending on circumstances the full opposite rudder may take from 1/2 turn to several turns to effect recovery. The recovery sequence always begins with opposite rudder (Step on the high wing of the turn coordinator--step on the heavy rudder pedal). Second, after the rudder starts to become effective, move yoke full forward. Spin may speed up momentarily. The recovery actions do not agree with your natural instincts. Spin recovery must be a learned response. Moving the ailerons against the spin will delay recovery.
When the spin is broken we must once again use the rudder and yoke to return to level flight. Speed will increase rapidly. These inputs must occur partially to recovery stable flight without over-stressing the aircraft. A precision one-turn spin should lose 5-600 feet and recovery at 2.5 to 3 Gs.
I was just looking through your website. You have a lot of good information on there. Being an aerobatic pilot I was especially interested in the spin awareness section. There's one statement in there that could get some pilots in trouble if they don't recognize what's happening. It's in the recovery part where your website states: "Recovery: Immediately, power off, opposite rudder, forward on yoke always in this sequence. If rudder is effective yoke forward may not be necessary. Otherwise, hold full application of controls until recovery". Many people would read that and think they should push the yoke all the way forward to recover. This would be a big mistake. The yoke should go to neutral on recovery. If you push in full opposite rudder and full forward yoke the rotation of the spin would first increase and then the plane would cross over into an inverted spin.
The untrained pilot might not even notice the change because the rotation of the aircraft over the ground would be the same as it was before the attempted recovery. Just thought I should point that out. Someone might read that and go try it with no training and get themselves in trouble.
Bill Clute http://billcluteairshows.com
Requires inverted flight so you roll inverted, reduce the power, apply yoke full forward to stall before rudder kicked in. Nose will drop out of the stall and power is applied to continue inverted level flight.
Inverted flat spin
From inverted flight stall the airplane. Apply full rudder at the stall.
The nose indicates spin direction. Things are moving and sliding. To flatten the spin, apply full aileron in the same direction as the rudder and apply full power. To recover from an inverted spin use opposite rudder and hold yoke back. It is possible to recover from a spin with full opposite aileron. It is also possible to recovery by putting your hands over your head. It takes four full turns so have plenty of altitude.
Entry into the upright flat spin is to first enter a conventional spin and hold it until it stabilizes, two turns should be enough. Apply full opposite aileron and add full power. You must force yourself to hold in the aileron. The aircraft turns around its vertical axis at an deceptive high speed as it pivots about the down aileron. Recovery begins with reduction of power. Lift both hands into the air. Push full opposite rudder. It will take two turns to recover. Release the rudder only when the turning stops but before it begins in the other direction. Yoke will break the stall by itself. Recover from dive before speed builds up.
When yaw exceeds roll a flat spin exists. If in a flat spin with the nose within 45 degrees of horizon apply full aileron in direction of spin to reduce autorotational effect of the retreating wing. You are in a flat spin when release of back control pressure does not result in an additional lowering of the nose. This is the only spin in which the use of ailerons is recommended.
You can do both upright and inverted flat spins entered from any attitude. A standard spin entry to the left (upright) or right (inverted) from any attitude with power or add power at after the break and outside aileron and away she goes. Recovery requires 1/4 to 1/2 turn after power off.
Intentional flat spins are (almost?) always done inverted. That way, the rudder is in clear air and not blanked out by the horizontal stabilizer. There are few planes that can do them safely. For these planes, it is entered as a 'normal' inverted spin. Then power is added. This brings the nose up to the horizon, and the rotation is now almost pure yaw, with very little bank. Recovery is by reducing power, which allows the spin to go 'normal' This is not the usual response for an average plane! The few that can safely do flat spins have this unusual characteristic!) For an upright flat spin, take any conventional twin, and stall it with full power on one engine & full in-spin rudder. Unknown if you can recover from it! Just that you can get in to it, without an 'aerobatic' maneuver.
Inadvertent spins can be differentiated from spirals since a spin has a rapid descent with a low airspeed, while a spiral has a rapid descent with a high airspeed. Inadvertent spirals are more likely than spins under IFR conditions.
Over the Top
Caused by top rudder in a tight climbing turn
Over the Top spin
It sounds to me like the instructor demonstrated a "spin over the top" where you enter the spin from an accelerated stall with excessive top rudder. In this spin entry you do indeed come around so that it appears to be inverted going over the top. When you settle into the spin it is pretty well developed. The airspeed will NOT increase significantly while you are spinning.
During your recovery you first stop the spin with full rudder against the yaw. That leaves you in a fairly steep nose down attitude and stalled. A firm forward pressure on the yoke will put you into a position where the airspeed can be increasing quite rapidly. Of course you are then pulling back to return to level flight. You do
not want to pull back so hard you bend the airframe with excess G forces, so you ease the yoke back as the airspeed increases, treading the balance between excess G force in the pullout and excess airspeed during the pullout. If you keep the G force on the pullout below about 2 1/2 or 3 G's the airspeed can easily build up close to Vne. You do want to be gentle on the pullout if your airspeed is above Va! :-)
That description is fully consistent with a spin over the top followed by a textbook recovery and a gentle pull out to level flight. That is a spin I always enjoyed because it DOES appear to go inverted over the top! Much more fun than spinning out the bottom of a turn or the standard prosaic straight ahead stall and kick a rudder as it breaks to initiate a spin. When I learned to fly, one was required to demonstrate all of the different spin entries with appropriate recovery.
Entry into an over-the-top spin:
--Enter stall from full power climbing turn
--At the stall apply full top rudder.
--Aircraft will abruptly go inverted in the opposite direction and into a normal spin.
--Inadvertent entry likely during departure stall.
--By avoiding yaw (keeping ball in the middle) you avoid inadvertent entry.
Entry into an under-the-bottom spin
--Enter a stall from a gliding turn
--Add full bottom rudder and opposite aileron
--Nose will drop and lazily enter a spin
--Inadvertent entry likely during base to final turn
--By avoiding yaw (keeping ball in the middle) you avoid inadvertent entry.
--Not source of inadvertent spins
--Power off full stall with application of rudder
An uncontrollable spin is apt to occur when near aft C.G. Use of aileron to try to raise the down wing can aggravate such a spin. If yoke is applied before rudder an inverted spin may result. Because of higher stall speeds or misapplication of rudder, inadvertent spins are more apt to occur out of turns. Never demonstrate spins with an aft C. G., even at altitude.
A normal spin can be entered accidentally. A botched stall where the pilot applies instinctive backpressure and aileron opposite to the direction of rotation is the classic inadvertent entry. The instinct is to regain straight and level without breaking the stalled condition. Every flyer should be capable of safely entering and recovering from a spin. Spins, because they can be accidental, should not be considered aerobatic. Rather, they are an event that occurs in flying and should be a part of a flyer's experience.
Caused by excess bottom rudder used to speed up the turn as when turning from base to final.
Recoverable conditions leading to spins that kill every year. Recovery skills depend on practice. The key to stall recovery is recognition followed by promptly corrective control action. Every aircraft, even same type and model will stall ever so slightly in a different manner. The inadvertent stall, as its title states, does not occur unless you are distracted and unsuspecting. You don't need to enjoy or fear stalls to practice. Go with an instructor. Have the instructor set you up for an accelerated stall. (No longer an FAA requirement but worth learning to do and make a recovery.) This is similar to the stall that would occur on a tight turn from base to final. If possible get an aerobatic instructor to take you through a spin series caused from inadvertent stall situations.
More Spin Types
Accelerated spins with ailerons
Accelerated spins with elevator
Inverted spins accelerated with elevator (these hurt!)
Inverted flat spins
Knife edge spins.
Spins to the uninitiated should only be introduced if and when the student mentions the spins. Quarter or half turns are sufficient to demonstrate both cause and recovery techniques. Spins, in and of themselves, do not seem to improve flying skills. Accidental spins usually occur so close to the ground that no recovery is possible.
1. Power to idle
2. Ailerons neutral
3. Full opposite rudder
4. Yoke abruptly forward
This will work for practically every aircraft. However, older aircraft with larger rudders and inherently more unstable were both easier to spin and easier to make recover. The C-150/172 is engineered to be more stable and hence more difficult to spin and more difficult to recover.
If You Don't Use Procedures Recommended?
Power to idle or ...
Spin characteristics are accentuated with power on. The spin entry is faster, the spin develops full rotation speed sooner and the angle of attack of the most stalled wing will be higher. A recovery with power on may exceed the structural limits of the aircraft.
Ailerons neutral or...
If the wing stalls at the tip rather than the root the drop will be abrupt and without warning, causing instinctive application of aileron and further aggravation. Trying to raise the stalled descending wing with aileron will increase lift thereby increasing the drag inducing adverse yaw or yaw toward the down wing. The increase in drag causes the stall to become more severe producing even more roll. The spin can be prevented only if rudder/aileron inputs prevent any slipping or turning at the point of stall.
Use of ailerons, even away from the spin direction, may again cause the spin entry to be more abrupt, speed up attaining full rotation speed, give a higher angle of attack, cause more difficulty in making recovery, and cause any 'recovery' to be merely the entry into another spin.
Full opposite rudder or...
When the rudder is applied so that the tail is not behind the nose there is a span wise flow of air that causes the tip to stall before the wing root. Thus, we have the no warning spin entry. This is more likely if the spin is done away from the stall warning device. The rudder is actually the only effective control you have. It is the only one that works against both the yaw and rotation. Anything less than full application will be proportionately less effective. The relatively small rudders of modern aircraft make even more important the full correct application both in entry and recovery. (Note: The turn coordinator is the best way to be sure of the direction of turn.) Rudder alone will not give a recovery. As soon as rotation begins to slow the yoke must be moved abruptly and fully forward.
Yoke abruptly forward or...
A slow or slight forward yoke may actually serve to aggravate the spin. As soon as you first feel the negative G of the recovery release the yoke pressure. Spins and recoveries should be learned and practiced so that there are just as many recoveries as there are spins, unless you mastered swimming by going under twice and coming up once.
Historic Spin Requirements
Early private pilot test allowed 15-degree error on recovery. Commercial after 2 or 3 turns allowed 10-degree errors. Instructors no error allowed. It is best to avoid letting the number of spins exceed the number of recoveries.
One recovery works for all general aviation aircraft. It requires extreme mental discipline, however. The process is that as soon as the incipient phase begins, that is loss of control, wing drop and turn, immediately pull the power off and remove the flaps. Place your hands on your thighs, feet flat on the floor, and the airplane will recover by itself.
Current Spin Requirements
Stall awareness, spin entry, spins and spin recovery technique are now part of the aeronautical section of the knowledge requirements for the private, commercial and CFI ratings. The CFI who fails the spin oral will fail and must demonstrate spins on the CFI flight test.
For Required Spin Knowledge
FAR 61,105 (6)
I have given _________#____ the flight training and ground instruction in stall awareness, spin entry, spins and spin recovery techniques as requires by FAR 61.105 (6) and find him competent in this area.
Actual spin not required but recommended.
For Spin Awareness
I certify that I have given _____holder of pilot certificate # ________ ground and flight instruction in stall awareness, spin entry, spins and spin recovery technique and find that he/she meets the knowledge requirements required under FAR 61....see above.
For Spin Training (Required CFIs)
I certify that in accordance with FAR 61.187 (a)(6) I have given ___#_____ flight training in spin entry, spins, and spin recovery techniques and he/she has demonstrated instructional competency in those maneuvers.
Including AC 61-67B 5/17/91
Recommended reading: FAA-RD-77-26 GA Pilot Stall Awareness Study, AC61-21, AC91-23,Practical test standards, AOPA Avoiding the Stall/Spin Accident
Spins Revisited (Opinion)
If you don't want to spin -don't stall-
but if you do stall - keep the ball in the center while recovering-
but if you do spin - power off - full rudder opposing spin -
let go of stick (or follow flight manual procedure with stick) -
recover from dive while- not stalling and spinning again. Whew!!
Yaw Required to Spin
In any turn, the inside wing is traveling slower than the outside wing. Not much, but enough to make a difference in the angle of attack between the two wings.
As the speed increases the angle of attack decreases. As the speed decreases the angle of attack increases. You can see this clearly in a propeller. The pitch of the propeller blade is twisted so that it is much flatter toward the tip, where it is moving faster. This keeps the entire propeller near its optimum angle of attack.
To initiate a spin, some yaw is required. The most insidious spin entry is the "spin out the bottom." To spin out the bottom you make a skidding turn. A skidding turn occurs when you do not have enough bank for your turn rate. This is indicated by excessive rudder in the direction of the turn and usually insufficient bank. This is the most popular spin entry on the base to final turn and happens when you are trying to hold the bank down to the thirty degrees you instructor asked for, and tighten the turn to keep from blasting into the approach for the parallel runway, or at least to keep from going past the centerline of the runway. You add extra rudder to tighten the turn. This creates a yaw condition where the outside wing is speeding up, decreasing its angle of attack, and the inside wing is slowing down, increasing its angle of attack. This means the inside wing will reach stall AOA first and start to drop, steepening the bank. Most pilots will react instinctively to this dropping wing by using aileron to pick it up. That aggravates the stall by increasing AOA of the dropping wing and decreasing the AOA on the rising wing. You find you cannot pick up the inside wing, and the next thing you know you are entering a spin. It tends to sneak up on you.
What should you do when the inside wing starts to drop? Pick it up with the "top" rudder. That will yaw you back the other way and even out the AOA on the wings. Then you must get the AOA back down below stall AOA. A little forward pressure does that, and maybe a touch of power to regain your lost altitude.
The less common spin entry from a turn is a "spin over the top" which occurs when you have excess BANK. You now have rudder OUT of the turn. This causes the inside wing to speed up, decreasing its AOA, while the outside wing slows down, increasing its AOA and moving the outside wing toward stall first. What will usually happen is the outside, or higher wing will start to drop. As it does you will come level. Usually coming back to wings level will get both wings unstalled and you merely add a little forward pressure to move away from the stall and perhaps a bit of power to get your altitude back.
If you KEEP the outside rudder in, the yaw can continue past the level flight attitude and the formerly outside wing will continue to drop entering a spin in the opposite direction from the turn. You will likely be prepared to swear at this time that you went through full inverted on the spin entry! This happens as the wing continues to drop, while the other wing does not. You nose begins to drop and the rotation starts causing you to roll over the "high" side into the spin entry. It can be quite dramatic!
Either spin can be easily avoided by maintaining you airspeed at 1.3 Vs or higher and keeping your banks reasonable and your turn coordinated. Even a 45-degree bank will only increase your stall speed to about 1.14 Vs, which should still be well below your airspeed of 1.3 Vs at the time. Be aware though, that a bank steeper than 45 can quickly bring your stall speed up to and above 1.3 Vs.
Once you complete the base to final turn, and are wings level on final then you can start playing with uncoordinated flight. I recommend flying finals slightly differently than normal flight. I forget about coordination on final. Use the ailerons to bank the airplane sufficiently to slip enough to keep the airplane aligned with the centerline. Use the rudders independently of the ailerons to keep the nose of the airplane pointed toward the FAR end of the runway. Continue this to touchdown. You have automatically made the proper correction for any crosswind that you encounter! :-) If there is NO crosswind, you will maintain alignment with the centerline with the wings level. It works for me! :-)
January 25, 2001 AVweb's Question of the Week:
"What, if any, benefits did you get if you received spin training?" 956 responses
--Increased knowledge of what an airplane can and cannot do. (6%)
--Increased confidence in my skills. (5%)
--Increased awareness of the need for precision during critical phases of flight. (5%)
d. All of the above. (82%)
e. Other (3%)
"Do you feel spin training should be required to become a certificated pilot?" 1181 responses
a. Yes. (57%)
b. No. (7%)
c. Encouraged, but not required. (36%)
--Stall/spin articles appearing in aviation magazines continue to be well received by readers, too. And the demand for stall/spin training at established
aerobatic schools is as strong as ever.
--One-third of stall/spin accidents in an NTSB study involved pilots with more than 1,000 hours of flight time.
--The median pilot experience of those involved in stall/spins was 400 hours
--We can profile who is most at risk of an accidental stall/spin as follows:
--It's the pilot who has logged fewer than 1,000 hours
--It’s the pilot who is on a daytime pleasure flight in good weather
--It’s the pilot who is in the traffic pattern
--It’s the pilot who is either turning or climbing.
Leading up to the inadvertent stall/spin
--It’s the pilot who will be distracted into making a critical error in judgment.
--It’s the 1/3 of the pilots who will fixate on the unfolding accident and
will not hear the stall horn.
–It’s the pilots with fewer than either 500 hours total time, or 100 hours in type
--699,653 active pilots who logged an estimated 47.9 million flight hours.
--U.S. pilots averaged 68 hours each that year
--1990s average pilot flight time was only 50 hours.
--Average active flying career of a G. A. pilot is estimated to be 17 years.
--50 hours per year for 17 years pilot will accumulate close to 850 hours total time.
--Most pilots will be in the of the stall/spin accident zone throughout their aviation careers.
--Mid-airs are statistically of less concern compared to the inadvertent
--The stall/spin problem is neither like an everlasting rain cloud over the airport It will get everybody.. .
--No segment of the pilot population is immune the stall/spin cloud over the traffic pattern..
--Average pilots on average flights fit the average stall/spin profile.
--Once entered into the spin the prospects for survival is greatly reduced.:
--One out of four aircraft fatalities are derived from the stall/spin.
--An 80 percent chance of serious or fatal injury in any accident involving the stall/spin..
--There is a 90 % chance that insufficient altitude exists in which to recover.
--19 % of stall/spin accidents are associated with the flight training process.
--A CFI is in the plane 11% of the time that a stall/spin accident occurs...
--All pilots will benefit from spin training beneficial.
--A national spin training requirement for private pilots is not feasible..
--The G. A. infrastructure is not adequate for a safe program.
--There is a need to reinforce valid arguments, clarify the ambiguous ones, and debunk the myths,
--To expand our knowledge so pilots can reasonably improve
their stall/spin awareness.
--Spins place specific demands on pilots and airplanes.
--Spins are unforgiving of incapacity, incompetence or neglect.
–Uses myth that pilots believe aerobatics training makes recovery from inadvertent spin at traffic pattern altitudes.
--I have yet to come across any pilot whose motivation to learn more about stall/spins was rooted in a belief that it would enable him/her to recover from a spin in the traffic pattern.
I have yet to meet rational proponents of spin training who
claim spin training would allow a pilot to recover from a spin encountered in
the traffic pattern.
--Pilots certainly are smart enough to realize that if a stall is allowed to progress into a spin at traffic pattern altitudes, the probability of survival is slim regardless of prior training.
--The primary reason proponents advocate, and pilots seek out,
additional stall and spin training is--surprise!--spin prevention.
–The advertised objective of spin training is to expand a pilot's knowledge, experience, and skill set to prevent an inadvertent spin departure in the first place.
--Another myth cited in the AOPA study is "watch your airspeed, or you're going to stall this airplane!" The study claims that this myth is largely propagated by flight instructors, …
--This airspeed myth is propagated by CFIs, textbooks and publications.
--Myth not supported by professionals in spin and aerobatics
AOPA Pilot magazine states that FAA dropped the spin requirement for the private certificate in 1949 because more pilots were killed in spin training than in actual situations.
--Mandatory spin training was removed in 1949 by requiring stall instruction and prevention training.
–Belief was that removal of spin and replacement of stall training resulted in greater air safety.
--Stall was considered to be the most dangerous maneuver to
-- Hope was that anti-spin- aircraft would come into use. Never happened.
--A survey in1997 found
--Programs on spin/aerobatics training was 5 to 29 years.
–About 135,000 hours of instruction given:
--Over 250,000 spins. or 12,000 vertical miles of flight.
–No accidents. to this date in 3003.
The New AOPA Study
--The study reinforces the importance stall/spin awareness and prevention.
--Legitimate spin training is capable of supplying the ability
to avoid spinning.
–Proper spin training will increase the importance of spin avoidance to the pilot.
--The practical knowledge about mechanisms of spinning, the importance of operating limitations and misapplied controls is a life and death matter to every pilot. Your instinct will kill you.
Aviation Pilot Stall Awareness Training Study
FAA-RD-77-26, September 1976, 75 Instructors
--Spins should be required -- 65%
--Pilots who had stall/spin awareness training--without spin training--were 33% less likely to enter a spin from an inadvertent stall.
--Pilots who had stall/spin awareness training with spin training—were 100% less likely to spin from an inadvertent stall..
--This FAA study has fueled the changes made to the training required regarding stall/spin awareness since 1976.
--This FAA study is not a reference used by the anti-spin
--13,680 G.A. accidents 1973-83
--Single-engine airplanes 1 or 2 people on board.
--Student pilots lowest stall/spin fatality rate at 4%
--30 % of private pilot accidents caused by lack of skill or overconfidence..
--ATPs 7.5% of flying population have nearly 10% of spin accidents.
--ATPs have 3.5 %of all fatal and below 3% of non-fatal G.A.
–G.A. no more dangerous for ATP than professional flight.
–Overconfidence a greater factor than lack of skill in 60 percent of the ATPaccidents
--Aerobatics accidents, 13.7 % for ATPs and 6.5 % for private pilots;
--Fatal aerobatics accidents, 50 % ATP and 20% private pilots.
--ATPs to perform aerobatics at unsafe altitudes.
–ATP fatal stall/spin accident component in non-aerobatic phases of flight, were responsible for 13 percent of the fatalities
--ATPs aerobatics resulted in 38% of spin accidents.
--ATPs do better than average in normal flight
-- ATPs doing aerobatics are overconfident and under trained.
–ATPs are subject to the same human failings as other pilots.
--All pilot classes show deficiencies in training, judgment and stall/spin awareness
--Experienced pilots have 2.5 times as many accidents involving spins than do student pilots.
Instructors Can Be Dangerous
--60 percent of stall/spins with an instructor aboard.
--91% of fatal stall/spin accidents with an instructor.
--20% of stall/spin accidents during instructional flight...
--Students have a better record when solo than when with an
--Students are two times more likely to have a stall/spin accident when with an instructor.
Instructional Background (1993)
–94% relied on popular literature;
--96%also instructors relied on their own instructors.
--95% failed ever to receive training in spin dynamics or conditions causing an inadvertent spin.
--94% of the instructors didn’t know spin certification
FARs, nor limitations imposed.
--98 percent said training consisted of no ground instruction and a mere two spins--one in each direction.
--All had logbook endorsements certifying that they were competent to teach spins.
--97% unaware of the FAA spin changes of 1991 included in AC
NTSB Aerobatics Accidents (1972-1974)
--Stalls and spins were primary accident types in 49 of 105 cases A 47% percent stall/spin accident rate. ----Most stall/spins were unintentional and were related to other aerobatics maneuvers at unsafe altitudes.
--A number of the stall/spins were intentional at safe altitudes.
--Most pilots had some previous spin instruction
--Knowledge and proficiency minimal.
--Not fully aware adverse spin characteristics caused through improper use of the flight or power controls..
--Not aware of need to use a precise technique to achieve the
--24% of the accidents involved CFIs/
--Age ranges 11 > 30; 10 > 50; 3 > 50
--Flight time 8 > 3000; 2<600;
--Time in type 14 < 300; and 6 of the 14 <
--CFIs were in 23% of the accidents and 39% of the spins.
--58% of crashing instructors did so in a spin.
--Pilots spend only 6% of time near airport
--This 6% accounts for 57% of accidents.
--Disproportionate amount of student time spent at airports.
--Airport pattern flying has high percentage of slow-flight
–Landings per hour is far lower for pilots than for students.
--Student are most experienced in flight region prone to stall spins.
--Best possible rate theoretically is at 2%.
--Student rate of 4% as good as practical.
–Airplanes type-certificated prior to 1950 with 500 registered
--Fatal stalls-plus-spins accident rate for this subset of airplanes was 42%.
--In 1970 the same airplanes were in 48% of the stall/spin
accident rate between 1945 and 1948
--Kit airplanes between 1983 and 1997 of 701 fatal accidents, unintentional stall/spin preceded ground impact in 45 percent of the cases.
–It seems that removal of spin training in 1949 had little effect on the stall/spin accident rate.
--Greatest change in the stall/spin accident rate came about
as a result of the influx of newer designs.
–Appears that previous "spin training" prior to 1949 and "stall avoidance" were equally effective.
--With the newer designs, the stall/spin accident rate declined.
--The stall/spin accident rate remains the same as does the make up of our flight lines.
POH Stall Altitude Losses
1.Intentional stall tests;
2. Performed at altitude
3. Wings level
4. Held into spin for one turn before recovering
3. Conducted under ideal conditions;
4. Using airplanes finely tuned to exact factory specifications;
5. With FAA-DER Test Pilots at the controls;
6. Without emotional duress.
--Loss of twice POH altitude
--Presence of shock and surprise
--Duress due to altitude
--Stalls can lose as much altitude as spins before recovery
Stall vs Spin
--He who reacts instantly and correctly a stall will recover sooner than he who enters a spin.
--He who freezes on the controls at the onset of a stall will lose more
altitude than the pilot who spins.
---Any meaningful comparison between the stall and spin must state the conditions and assumptions.
--Those advocating the anti-spin training agenda always attempt to measure the advantages of spin training against an hypothesis that is illogical.,
--He who has an incomplete understanding of stall/spin dynamics and improper control is an active participant in creating the event.
--When is the probability of a spin trained pilot encountering an inadvertent
spin departure in the traffic pattern greatest? Think density altitude.
Protecting Yourself from Stall/Spin Accidents
--Read FAA AC 61-67C, Stall and Spin Awareness Training
–Follow up on AC61-67C recommendations
--Look at AC 61-67B
--Learn about the 30-degree bank
Required Knowledge about Stalls and Spins
--Stall/spin effects and definitions
--Weight & balance considerations
--Airworthiness and certification standards
--Wing contamination effects
--Typical stall/spin accident scenarios
--Types of stalls
--Types of spins
--Typical recovery errors
--Stall avoidance practice at slow airspeeds
--Engine failure while in a climb followed by a gliding turn
--Cross-controlled stalls in gliding turns
--Stalls during go-around
--Elevator trim stalls.
--Power-on and power-off stalls
--Spin avoidance training using realistic distractions
--Intentional incipient spins
--Spin entry, spin, and spin recovery
--Spin departures from unusual attitudes.
--Pilots seek to expand their comfort levels
--Pilots seek to develop additional awareness to prevent a stall/spin departure close to the ground:
Stepping on the Sky
I heard it somewhere. What does it mean? It's in relation to spin training.. Does it mean to step on the side of the rudder where you see the most sky?
It's a term that is part of the most popular unusual attitude recovery mantra. It deals with rudder use during unusual attitude recovery and is part of the process:
1. Push. Push the autopilot off and push the yoke to unload any Gs.
2. Power. Increase if nose is high; decrease if nose is low.
3.. Rudder. If nose is low, "Step on the sky".
4.. Roll. Roll wings level before pitching up to horizon.
5.. The important thing to remember in all this is to roll to the nearest
In Charge of the Spin
Try to really learn the aerodynamics of the spin such as why a descending stall will spin under the bottom and a climbing stall will spin over the top. Also try to understand how using rudder to control yaw affects the angle of attack of each wing and breaks the stall and also why the recovery may snap into an opposite spin if not performed properly.
Once you understand the why you will remove the uncertainty and confusion and will
control the fear. You will feel in control of both your brain and your aircraft.
At this point you will begin to really enjoy spins and will be able to experiment with variations of throttle and aileron to get a cleaner entry or to stabilize the spin. Situating over a road or such and counting half rotations and doing exercises like recovering on a heading will really sharpen your positional sense and you will need to know how much to lead your recovery in order to recover on the desired heading. When you get good at that get your instructor to call the heading to recover on after the spin has developed and you will learn to do the mental calculations during the spin which will give you great confidence.
Pick an aircraft with good spin characteristics. Using an aerobatic rated aircraft and parachutes combined with lots of altitude will also help with the confidence factor.
A Spin Virgin No More
Well as most of you know by now, my Commercial checkride is on hold while we wait for my FBO's only complex aircraft to get it's replacement engine.
So, last week (when my checkride had to be cancelled due to the Arrow III going off-line), I asked my CFII if we could work on some of the CFI training. More specifically, I asked him if we could start with working on the spin endorsement.
Today was the day! We started with some ground instruction regarding spins, which included me explaining the mechanics of a spin and being questioned on what were the specific caveats related to the aircraft we were using (a Cessna 152). My initial 'explanations' missed the mark initially (that is being plain enough to serve as an apt explanation to a student who had no understanding of spins), but with my CFII's help I was able to 'rein-in' my explanation so that it was more clear and concise. We did the weight and balance calculations to make sure that we would be well within the W & B 'envelope' and we were.
After our ground instruction session together it was time! I told John that I had only one 'disclaimer', that being - I had never done this before and wasn't sure how I'd 'be'. Though I went on to say that my level of curiosity had easily grown to a level that easily out-measured any fear/concerns I may have about spins. John, told me that often he had heard from his students that the actual spin was far less ominous/frightening than their (i.e., the students) imaginings were. I told my CFI that may very well be and the 'proof would be in the pudding' so-to-speak; that is after I had my first spins.
Took off from Reid-Hillview and headed out to the practice area. John had me climb to 5,000 feet and then perform some clearing turns. As he mentioned to me earlier, he reminded me that he would demonstrate the first one (with my hands and feet on the controls - following with him) and then the second spin, I would do the entry and recovery with him verbally coaching as necessary.
Here it goes! John reduces the power to idle and just as the plane begins to stall he steps on the rudder in the direction he wanted to begin the spin (he picked my side to start with). I was amazed how the 152 responded by immediately entering the incipient spin and then 'full' spin. I have to tell you, the first spin was not 'scary' (and this is not male bravado speaking, at all) rather it was first just a matter of getting my brain to 'comprehend' all the new 'visual inputs' it was getting. The earth was turning below in my windscreen, I was in a spin.
Then John smoothly applied opposite rudder (the rotation stopped) and released the back pressure on the yoke and we were now in a steep dive which he carefully pulled us out of. .I must say that the worst part (at least for me) of the maneuver are the 2 to 2.5 G's you pull when coming out of the dive. My head and the stomach did not enjoy that part, but once we were back to straight and level and 'normal weight' <g> I felt a bit better. Though I did feel a bit 'heady' (NOT dizzy) more just that my inner ear had been put though a good workout (specifically the semicircular canals). I remember experiencing something similar during recovery from unusual attitudes practice from my other pilot training.
I told my instructor that the spins weren't anywhere what I had imagined them to be like. I told him too that I felt a little bit heady, but that I wasn't going to lose any lunch yet, but I would keep him apprised of my status as we went through the maneuver.
So, now it was my turn. I (though it wasn't necessary) told my instructor that he might want to follow me through on the controls just in case I had an unexpected reaction resulting in an incorrect control input. John told me that if he needed the plane he would say 'my plane' and I would turn it over to him if necessary; though he went on to say that he really didn't think I was going to have a problem.
I did some more clearing turns. Brought the power to idle, kept raising the nose until the wing stalled and then stepped down on the left rudder - over we went - incipient spin to one full spin and recovery. I was impressed with myself. Not really a trace of hesitating to enter the maneuver nor delay in recovery - after all, I had never done this before; just read about spins endlessly <g>.
Head and tummy doing 'decently'. Surprisingly, I was not having any ill feelings about the spin itself, rather it was that g-pull at the bottom that my physiology didn't care for in the slightest.
I gave my 'head & tummy' status report to John; all seemed to be okay, for the most part. So John said he would demonstrate (with me following through on the controls) an incipient spin, followed by 2 full spins. After he performed them he had me do the same. At this point I was already to do the spin,,, actually (except for the head-tummy issues) I was eager to do another spin, myself. So, in I went,,, recovered and of course; yuck that g-sensation thing.
I told John that I could probably do another but that should probably be 'it' for the day as far as what my head and stomach would likely tolerate (I was just being safe, 'cause I haven't gotten sick in a plane yet and I would like to keep my 'perfect record' <grin>). John said that would be just fine and that he would end our session demonstrating (with me following through) a 3 turn spin with recovery. At this point my brain was becoming quite accustomed to the visual input and I was actually 'casually' (in a manner of speaking <g>) counting each full turn and then recovery..... We timed the session quite well as I was stopping just at the point where there would be no 'point-of-no-return' as far as nausea might go.
Headed back to RHV, landed in the slight crosswind (still got to confess that the heady-nausea thing hadn't left me yet) and we tied down the plane and debriefed. I thanked my instructor for making it such a positive experience (after all, I liked the spins,,, wasn't his fault my nausea 'threshold's needing a little more exposure).
I drove home, but not before stopping at a local supermarket to pick up a bottle of ginger ale and some pretzels. Like I told my instructor there was no way I was going to eat a hamburger right now. So, I sipped on the ginger ale and carefully nibbled at the pretzels, since it was all I could safely get into me at the time.
Now it is almost 7:40PM and it wasn't 'till about 40 minutes ago that I started to feel 'normal' again (finished my flight lesson at 3PM).
Well, I did it! My first spins!!! They weren't the visual 'dragons' that I had imagined them to be and by the 3rd one I was actually kind of enjoying them (though I was clearly not enjoying the mild motion sickness issues on the g-pullout). Regarding the motion sickness issue, I'm not too concerned. As I've learned from the past; it is just a matter of exposure.
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Continued on 3.28 Ground Reference