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Pilot's Handbook of Aeronautical Knowledge
Aeromedical Factors

Health and Physiological Factors Affecting Pilot Performance

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Pilot's Handbook of Aeronautical Knowledge



Table of Contents

Chapter 1, Introduction To Flying
Chapter 2, Aircraft Structure
Chapter 3, Principles of Flight
Chapter 4, Aerodynamics of Flight
Chapter 5, Flight Controls
Chapter 6, Aircraft Systems
Chapter 7, Flight Instruments
Chapter 8, Flight Manuals and Other Documents
Chapter 9, Weight and Balance
Chapter 10, Aircraft Performance
Chapter 11, Weather Theory
Chapter 12, Aviation Weather Services
Chapter 13, Airport Operation
Chapter 14, Airspace
Chapter 15, Navigation
Chapter 16, Aeromedical Factors
Chapter 17, Aeronautical Decision Making




Demonstration of Spatial Disorientation
There are a number of controlled aircraft maneuvers a pilot
can perform to experiment with spatial disorientation. While
each maneuver will normally create a specific illusion, any
false sensation is an effective demonstration of disorientation.
Thus, even if there is no sensation during any of these
maneuvers, the absence of sensation is still an effective
demonstration because it illustrates the inability to detect
bank or roll. There are several objectives in demonstrating
these various maneuvers.

1. They teach pilots to understand the susceptibility of
the human system to spatial disorientation.
2. They demonstrate that judgments of aircraft attitude
based on bodily sensations are frequently false.
3. They help decrease the occurrence and degree of
disorientation through a better understanding of the
relationship between aircraft motion, head movements,
and resulting disorientation.
4. They help instill a greater confidence in relying on
flight instruments for assessing true aircraft attitude.

A pilot should not attempt any of these maneuvers at low
altitudes, or in the absence of an instructor pilot or an
appropriate safety pilot.

Climbing While Accelerating
With the pilot's eyes closed, the instructor pilot maintains
approach airspeed in a straight-and-level attitude for several
seconds, then accelerates while maintaining straight-and level
attitude. The usual illusion during this maneuver,
without visual references, is that the aircraft is climbing.

Climbing While Turning
With the pilot's eyes still closed and the aircraft in a straight and-
level attitude, the instructor pilot now executes, with a
relatively slow entry, a well coordinated turn of about 1.5
positive G (approximately 50° bank) for 90°. While in the
turn, without outside visual references and under the effect of
the slight positive G, the usual illusion produced is that of a
climb. Upon sensing the climb, the pilot should immediately
open the eyes to see that a slowly established, coordinated
turn produces the same sensation as a climb.

Diving While Turning
Repeating the previous procedure, except the pilot's eyes
should be kept closed until recovery from the turn is
approximately one-half completed, can create the illusion
of diving while turning.

Tilting to Right or Left
While in a straight-and-level attitude, with the pilot's eyes
closed, the instructor pilot executes a moderate or slight skid
to the left with wings level. This creates the illusion of the
body being tilted to the right.

Reversal of Motion
This illusion can be demonstrated in any of the three planes
of motion. While straight and level, with the pilot's eyes
closed, the instructor pilot smoothly and positively rolls the
aircraft to approximately 45° bank attitude while maintaining
heading and pitch attitude. This creates the illusion of a strong
sense of rotation in the opposite direction. After this illusion
is noted, the pilot should open his or her eyes and observe
that the aircraft is in a banked attitude.

Diving or Rolling Beyond the Vertical Plane
This maneuver may produce extreme disorientation. While
in straight-and-level flight, the pilot should sit normally,
either with eyes closed or gaze lowered to the floor The
instructor pilot starts a positive, coordinated roll toward a
30° or 40° angle of bank. As this is in progress, the pilot
tilts his or her head forward, looks to the right or left, then
immediately returns his or her head to an upright position.
The instructor pilot should time the maneuver so the roll is
stopped as the pilot returns his or her head upright. An intense
disorientation is usually produced by this maneuver, and the
pilot experiences the sensation of falling downward into the
direction of the roll.

In the descriptions of these maneuvers, the instructor pilot is
doing the flying, but having the pilot do the flying can also
be a very effective demonstration. The pilot should close his
or her eyes and tilt the head to one side. The instructor pilot
tells the pilot what control inputs to perform. The pilot then
attempts to establish the correct attitude or control input with
eyes closed and head tilted. While it is clear the pilot has no
idea of the actual attitude, he or she will react to what the
senses are saying. After a short time, the pilot will become
disoriented and the instructor pilot then tells the pilot to look
up and recover. The benefit of this exercise is that the pilot
experiences the disorientation while flying the aircraft.