being forward of the C.P., then causes the aeroplane to nose-
down, and assists the pilot in making a reasonably small
loop along the course C and in securing a quick recovery.
If the engine is not throttled down, then the aeroplane may
be expected to follow the course D, which results in a longer
nose dive than in the case of the course C.
A steady, gentle movement of the elevator is necessary.
A jerky movement may change the direction of motion so
suddenly as to produce dangerous air stresses upon the surfaces,
in which case there is a possibility of collapse.
If an upside-down flight is desired, the engine may, or
may not, be throttled down at point A. If not throttled
down, then the elevator must be operated to secure a course
approximately in the direction B. If it is throttled down,
then the course must be one of a steeper angle than B, or
there will be danger of stalling.
Diagram p. 88.--This is not set at quite
the correct angle. Path B should slope
slightly downwards from Position A.
CHAPTER III
RIGGING
In order to rig an aeroplane intelligently, and to maintain
it in an efficient and safe condition, it is necessary to possess
a knowledge of the stresses it is called upon to endure, and
the strains likely to appear.
STRESS is the load or burden a body is called upon to
bear. It is usually expressed by the result found by dividing
the load by the number of superficial square inches contained
in the cross-sectional area of the body.
Pages:
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114