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DEFINE a spin
An aggravated stall that results in autorotation
- Two conditions required:
- the aircraft must be stalled
- yaw must be present
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DEFINE autorotation
a combination of roll and yaw that propagates itself due to asymmetrically stalled wings.
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DESCRIBE the aerodynamic forces affecting a spin
The spin axis is the aerodynamic axis around which stall and yaw forces act to sustain spin rotation.
- Poststall Gyration Phase
- During a stall, lift and drag of both wings are equal unless yaw is introduced.
- Yaw creates an AOA difference between the left and right wings.
- For example, an aircraft stalls and rolls left. The down-going (left) wing senses a roll relative wind from beneath. This relative wind is added to existing relative wind and creates an average relative wind that is further from the chordline.
- Down-going wing has a higher AOA and becomes more stalled.
- The up-going wing senses a roll relative wind from above. It is added to the existing relative wind which creates a lower AOA and the wing is less stalled.
- The AOA differential results in two cases:
- Up-going wing: lower AOA, more lift, less drag
- Down-going wing: higher AOA, less lift, more drag
- The lift differential results in a continued rolling motion of the plane.
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STATE the characteristics of erect, inverted, and flat spins
- Erect spins
- Upright
- Result from positive-g stall entries.

- Inverted spins
- occur from a negative-g stall.

Flat spin is characterized by a flat attitude and transverse or "eyeball out" Gs. The cockpit indications will be similar to an erect spin, except airspeed may vary depending on how flat the spin is.
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DESCRIBE the factors contributing to aircraft spin
- Ailerons
- Applied in the direction of spin will cause increased roll and yaw oscillations
- Applied in the opposite direction of spin will tend to dampen roll and yaw.
- In the T-6B, apply neutral ailerons since the wings are in a deep stall.
- Rudder
- The principal control for stopping autorotation in the T-6B.
- Deflected in the same direction of the spin, the amount of rudder exposed to the relative wind will be minimized and result in less drag.
- Deflected in the opposite direction of the spin will maximize the amount of rudder exposed to the relative wind and the amount of drag.
- The drag is divided into a horizontal and vertical component.
- The horizontal component creates a force that oppose the yaw to slow the rotating rate.
- The vertical component creates a force that pulls the tail up and pitches the nose-down, reducing the AOA on both wings.
- Elevator
- The drag will cause a more nose down pitch attitude.
- Full aft stick results in the flattest pitch attitude and slowest spin rate.
- Weight
- A heavier plane will have a slower spin entry with lesser oscillations due to this large moment of inertia
- A lighter plane will enter a spin more quickly, with greater oscillations possible, but will also recover faster.
- Pitch Attitude
- Will have a direct impact on the speed the aircraft stalls.
- As a plane increases its attitude, a larger portion of thrust is in the vertical, adding lift.
- This additional lift reduces the load seen by the wings allowing for a slower stall speed, making the spin entry slower and with less oscillations.
- At lower pitch attitudes, the aircraft stalls at a higher airspeed and entries are faster and more oscillations.
- Spin Direction
- If in a right spin, the T-6B will tend to pitch down due to gyroscopic precession.
- If in a left spin, the T-6B will tend to pitch up due to gyroscopic precession.
- The T-6B will have a flatter attitude when spinning to the left than to the right.
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DISCUSS the effects of weight, pitch attitude, and gyroscopic effects on spin characteristics
- Weight
- A heavier plane will have a slower spin entry with lesser oscillations due to this large moment of inertia
- A lighter plane will enter a spin more quickly, with greater oscillations possible, but will also recover faster.
- Pitch Attitude
- Will have a direct impact on the speed the aircraft stalls.
- As a plane increases its attitude, a larger portion of thrust is in the vertical, adding lift.
- This additional lift reduces the load seen by the wings allowing for a slower stall speed, making the spin entry slower and with less oscillations.
- At lower pitch attitudes, the aircraft stalls at a higher airspeed and entries are faster and more oscillations.
- Spin Direction
- If in a right spin, the T-6B will tend to pitch down due to gyroscopic precession.
- If in a left spin, the T-6B will tend to pitch up due to gyroscopic precession.
- The T-6B will have a flatter attitude when spinning to the left than to the right.
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STATE how empennage design features change spin characteristics
- The T-6B uses a dorsal fin, strakes, and ventral fins to decrease the severity of spin characteristics.
- Dorsal fin is attached to the front of the vertical stabilizer to increase its surface area to decrease the spin rate and aids in stopping autorotation.
- Ventral fin is located beneath the empennage. It decreases the spin rate and aid in maintaining a nose down attitude.
- Strakes are located in front of the horizontal stabilizer. They increase the surface area of the horizontal stabilizer in order to keep the nose pitched down and prevent a flat spin. The strakes change the airflow over the nose to create an anti-rotational force.
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STATE the cockpit indications of an erect and inverted spin
- Erect Spin
 - Inverted Spin

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DESCRIBE the pilot actions necessary to recover from a spin
- Erected Spin Recovery
- 1. Gear, flaps, and speed brake – Retracted
- 2. PCL – IDLE
- 3. Rudder – Full opposite to turn needle deflection
- 4. Control stick – Forward of neutral with ailerons neutral
- 5. Smoothly recover to level flight after spin rotation stops
- Inverted Spin Recovery
- Look in T-6 Flight Manual.
- The spin will recover to a steep, inverted, nose down dive.
- Roll or split-S out of the dive to level flight in a timely manner as airspeed will build rapidly.
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DESCRIBE a progressive spin
- Occurs if proper recover procedures are not followed and the pilot puts the full opposite rudder but inadvertently maintains full aft stick.
- After one or two more turns, the nose will pitch steeply down and the plane will snap into a reversed direction of rotation.
To recover, apply full rudder opposite the turn needle and stick slightly forward of neutral.
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DESCRIBE an aggravated spin
- Caused by maintaining pro-spin rudder while moving the control stick forward of the neutral position.
- Neutralizing rudder while advancing the stick may also cause it.
- Characterized by steep nose-down attitude (approx. 70 degrees nose down) and an increase in spin rate (approx. 280 degrees per second).
- In addition, they tend to induce severe pilot disorientation.
- Recovery is the same as a progressive spin. (apply full rudder opposite the turn needle and stick slightly forward of neutral.)
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