Physiology of Instrument Flight

CHAPTER ONE

BASIC INSTRUMENT PROCEDURES

10. If in a clean configuration, the 2F101 will utilize 30 angle of bank in turns. If the gear is

down, the 2F101 will utilize about 7 angle of bank. If in transition to or from the landing

configuration, nobody can predict exactly what angle of bank it might use, but it will probably be

between 7 and 30 degrees. Calculations to lead turnpoints and to intercept arcs and radials must

take into account the 7 angle of bank with the gear down, as well as the various airspeeds,

which would be flown with flaps at different positions.

11. When the 2F101 transitions to a gear down configuration, it will then fly at 15 units angle

of attack and the airspeed cannot be changed.

12. The 2F101 is programmed so that a reduction of power is associated with descents, and

increases in power are associated with increases in airspeed. A request for a simultaneous

descent and an increase in airspeed (such as descending out of holding) usually results in a long

delay in reaching the requested airspeed.

13. If the speedbrakes are closed during a descent, the 2F101 will frequently level-off as the

speedbrakes close, despite their being at a different requested altitude than level-off.

14. At times, the 2F101 will not perform a deceleration and transition to the landing

configuration while in a descent. The student should request the pilot "slow to gear speed"

without regard for this trainer shortcoming, and the instructor will comply with the request as

soon as possible thereafter.

101. PHYSIOLOGY OF INSTRUMENT FLIGHT

During flight, the sense of sight is used to determine the aircraft's attitude in relation to the

earth's surface. In visual flight conditions, the aircraft attitude is determined by reference to the

earth's horizon and flight instruments. During instrument flight conditions, when the earth's

horizon is not visible, the aircraft attitude must be determined by referencing the attitude

indicator and other flight instruments.

During instrument flight conditions, the sense of sight may disagree and conflict with supporting

senses and equilibrium may be lost. When this happens, the pilot is susceptible to spatial

disorientation and vertigo. The degree varies with the individual, his proficiency, and conditions

that induced it. To recognize and successfully overcome the effects of false sensations that may

cause spatial disorientation, it is important to understand the senses affecting a pilot's ability to

remain oriented.

The ability to maintain equilibrium and orientation depends on various sensations or signals,

from three sources. These sensations come from the motion-sensing (vestibular) organs of the

inner ear; the postural senses of touch, pressure, tension; and the sense of sight. If one of these

sensory sources is lost or impaired, the ability to maintain equilibrium and orientation is reduced.

Fatigue and dehydration will invariably induce sensory impairment: the need for adequate crew

rest and proper hydration should never be overlooked.

1-4 BASIC INSTRUMENT PROCEDURES