CHAPTER THREE CHG 2
broken layer, or when launching at night with no clear horizon. Vertigo or the disorientation
sensation is and always will be a factor in aviation, but is dangerous only when the pilot believes
and flies his senses instead of the reliable instruments.
The vertigo training in the T34C will demonstrate and emphasize three specific facts:
A pilot's attitude sensations are generally unreliable.
Sensations being unreliable, the pilot cannot recover to straightandlevel flight using these
The instruments are the only reliable way to recognize and recover from any unusual attitude.
The first objective, which is to prove senses unreliable, is accomplished on the first flight in
Basic Instruments. The instructor will fly the aircraft through a series of smooth, easy
maneuvers while the student remains unhooded with his eyes closed. The student gives a
running commentary of his sensations over the ICS. When disorientation is evident, the student
will be informed to open his eyes and check his attitude. This will vividly emphasize the
unreliability of body feelings.
It should be noted that "eyes closed" simulates inattention to the instruments, which may occur
any time a pilot is tuning radios, checking maps, or attempting to maintain VFR scan in marginal
conditions. The maneuvers performed are smooth and constant, producing the typically smooth,
insidious vertigo. They are not the accustomed violent maneuvers usually associated with
unusual attitudes which produce an immediate indication of abnormal flight. Instead, the
simulated inattention induces real disorientation. The maneuvers or the recoveries from them
will not be graded. It is the intention of the demonstration to emphasize the seriousness of
vertigo. The student's susceptibility to vertigo (or his immunity) is in no way being evaluated.
Fatigue, turbulence, dim lighting, and IFR conditions all contribute to the onset of vertigo.
BASIC INSTRUMENTS FLIGHT PROCEDURES 3-45