Operation and nomenclature of the sight
RESTRICTED
SECTION V
OPERATION AND NOMENCLATURE, SIGHT
Purpose
of Sight
General
Descript-
ion of
Sight
N.O.P.
#849
A. Type
of sight
Fig. 30
B. Identi-
ficat-
ion of
Sight
M-3
exter-
The purpose of the bombsight is to enable the
bombardier to drop bombs with the greatest degree
of
accuracy.
In so doing the instrument sets
up
or determines a line of sight which, at the in-
stant of bomb release,
will subtend actual range
distance on the ground
or the horizontal distance
that the bomb will travel on its path through the
The bombsight also determines the proper
course of the
airplane in order to maintain the
necessary line of sight according to the prevail-
ing atmospheric conditions.
The bombsight is a stabilized instrument.
The cross hairs
of the telescope are mechanically
stabilized,
and
are stabilized
in the vertical by
the vertical gyro and about
the
vertical or in
Narden sight
the horizontal plane by the directional gyro. The
a synchronizing
mechanism.
term, synchronizing, means that the bombardier
by properly adjusting the course,
rate and
displacement knobs, cause the intersection of the
cross hairs to remain on
the point of aim or tar=
get by causing the mirror, in the M-6 and the tel-
escope in the M-3, to turn about its lateral axis
at the proper speed,
that is,
a speed proportional
to ground speed.
When the sight is properly cal-
ibrated and is
correctly synchronized, it will
accurately solve the bombing problem.
I n
considering
and
explaining the exterior
of the sight, we must bear in mind that right and
left,
bombardier's position.
The rate end of the sight
is to the bombardier's right and the vertical gyro
to his left.
The
bombardier
rear of the sight is
toward the
and the front away from him. The Navy
reverses these positions.
On the left end of the sight are the pre-
cession or leveling knobs.
These knobs give the
bombardier control over the vertical gyro so that
he may level it whenever he desires.
The center
knob causes the gyro to precess about its trans-
axis and in the fore and
aft plane.
to the rear of center causes the gyro to
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