Background
Instrument Flight
BACKGROUND
While some of the ideas presented in this FTI will be new to you, most will be familiar from your previous
training. You will be performing the same procedures in a much faster aircraft; consequently, events will
happen more quickly than you have experienced, so your margins for error will be reduced. In addition,
the digital attitude and navigation displays provide additional information that was not available in the
previous aircraft. You will need to manage these additional resources effectively to become a proficient
instrument pilot.
The importance of having the aircraft properly trimmed at all times is paramount. During any maneuver,
your trim should be such that the stick has a very light feel. The idea is for you to fly the aircraft, not for
the aircraft to fly you.
TRANSFER OF AIRCRAFT CONTROL
There will always be a two-way communication when transferring control of the aircraft. Since you will be
in the rear cockpit and usually under the hood, simply release the controls when the instructor says, “I
have the controls.” You will then reply, “You have the controls.”
In the event of a suspected ICS failure, the instructor may remove his mask and say, “I have the controls,”
and will shake the stick to take control. Stow the hood so that you can maintain visual communication
with the instructor. The instructor may also pump the stick to pass control back to the student.
SENSATIONS OF INSTRUMENT FLIGHT
During flight, you use the sense of sight to determine the aircraft’s attitude in relation to the earth’s
surface. In visual flight conditions, you determine attitude by reference to the horizon and flight
instruments. During instrument flight conditions, when the horizon is not visible, you can determine
attitude only by reference to aircraft instruments.
Under instrument flight conditions, the sense of sight may disagree and conflict with the supporting
senses, and equilibrium may be lost. When this happens, you may become susceptible to spatial
disorientation (false perception of position, attitude, or motion) and vertigo. The degree to which this
occurs will vary with the individual, his or her proficiency, and the conditions which induced it. To
recognize and overcome the effects of false sensation that may lead to spatial disorientation, you must
understand the senses affecting your ability to remain oriented.
The ability to maintain equilibrium and orientation depends on sensations, or signals, from three sources:
motion-sensing organs of the inner ear; postural senses of touch, pressure, and tension; and sense of
sight. If one of these sensory sources is lost or impaired, you reduce your ability to maintain equilibrium
and orientation.
MOTION
The sense of motion originating in the inner ear is very important in a person’s normal ground
environment. The inner ear registers linear and rotational acceleration and deceleration, thus it is able to
detect turns, slips, and skids during flight. Unfortunately, it is not capable of distinguishing between
centrifugal force and gravity.
Linear Acceleration
Centrifugal force and gravity are often fused together in flight, and the resultant force can only be
interpreted visually. For example, without a visual aid, a decrease in airspeed while turning may cause
the inner ear to sense a reverse turn; therefore, you must not rely on these unreliable sensations as a
primary cue.
Page 3
(4-01) Original
Previous Page
