Updated: Dec 8, 2020
Spin Awareness Lesson by wifiCFI
To determine that the applicant exhibits satisfactory knowledge, risk management, and skills associated with spins, flight situations where unintentional spins may occur and procedures for recovery from unintentional spins.
The applicant demonstrates understanding of:
Aerodynamics associated with spins in various aircraft configurations, to include the relationship between angle of attack, airspeed, load factor, power setting, aircraft weight and center of gravity, aircraft attitude, and yaw effects.
What causes a spin and how to identify the entry, incipient, and developed phases of a spin.
Spin recovery procedure.
The applicant demonstrates the ability to identify, assess and mitigate risks, encompassing:
Factors and situations that could lead to inadvertent spin and loss of control.
Range and limitations of stall warning indicators (e.g., aircraft buffet, stall horn, etc.).
Improper spin recovery procedure.
Effect of environmental elements on aircraft performance related to spins (e.g., turbulence, microbursts, and high density altitude).
Collision hazards, to include aircraft, terrain, obstacles, and wires.
Distractions, loss of situational awareness, and/or improper task management.
Spin Awareness (AFH C4)
A spin is an aggravated stall that typically occurs from a full stall occurring with the airplane in a yawed state and results in the airplane following a downward corkscrew path.
As the airplane rotates around a vertical axis, the outboard wing is less stalled than the inboard wing, which creates a rolling, yawing, and pitching motion.
The airplane is basically descending due to gravity, rolling, yawing, and pitching in a spiral path.
The rotation results from an unequal AOA on the airplane’s wings.
The less-stalled rising wing has a decreasing AOA, where the relative lift increases and the drag decreases.
Meanwhile, the descending wing has an increasing AOA, which results in decreasing relative lift and increasing drag.
In the entry phase, the pilot intentionally or accidentally provides the necessary elements for the spin.
The entry procedure for demonstrating a spin is similar to a power-off stall.
During the entry, the pilot should slowly reduce power to idle, while simultaneously raising the nose to a pitch attitude that ensures a stall.
As the airplane approaches a stall, smoothly apply full rudder in the direction of the desired spin rotation while applying full back (up) elevator to the limit of travel.
Always maintain the ailerons in the neutral position.
The incipient phase occurs from the time the airplane stalls and starts rotating until the spin has fully developed.
This phase may take two to four turns for most airplanes.
In this phase, the aerodynamic and inertial forces have not achieved a balance.
As the incipient phase develops, the indicated airspeed will generally stabilize at a low and constant airspeed and the symbolic airplane of the turn indicator should indicate the direction of the spin.
The slip/skid ball is unreliable when spinning.
The developed phase occurs when the airplane’s angular rotation rate, airspeed, and vertical speed are stabilized in a flightpath that is nearly vertical.
In the developed phase, aerodynamic forces and inertial forces are in balance, and the airplane’s attitude, angles, and self-sustaining motions about the vertical axis are constant or repetitive, or nearly so.
The spin is in equilibrium.
The recovery phase occurs when rotation ceases and the AOA of the wings is decreased below the critical AOA.
This phase may last for as little as a quarter turn or up to several turns depending upon the airplane and the type of spin.
Weight and Balance Requirements
In airplanes that are approved for spins, compliance with weight and balance requirements is important for safe performance and recovery from the spin maneuver.
Pilots must be aware that even minor weight or balance changes can affect the airplane’s spin recovery characteristics.
An airplane that is approved for spins in the utility category but loaded in accordance with the normal category may not recover from a spin that is allowed to progress beyond one turn.
Failure to apply full rudder pressure (to the stops) in the desired spin direction during spin entry
Failure to apply and maintain full up-elevator pressure during spin entry, resulting in a spiral
Failure to achieve a fully-stalled condition prior to spin entry
Failure to apply full rudder (to the stops) briskly against the spin during recovery
Failure to apply sufficient forward-elevator during recovery
Waiting for rotation to stop before applying forward elevator
Failure to neutralize the rudder after rotation stops, possibly resulting in a secondary spin
Slow and overly cautious control movements during recovery
Excessive back elevator pressure after rotation stops, possibly resulting in secondary stall
Insufficient back elevator pressure during recovery resulting in excessive airspeed
FAA Sources Used for This Lesson
Airmen Certification Standards (ACS)
Airplane Flying Handbook (AFH) Chapter 4