impact switch case, when illuminated, indicates the
switch has been actuated. Pressing the reset button
located adjacent to the impact switch light causes the
light to extinguish and restores power to the recorder.
b. The recorder system is powered through a
RECORDER POWER FLT, located on the copilot's
sidewall circuit breaker panel.
c. A battery powered, acoustic underwater
locator beacon assembly is mounted on the front panel
of the crash data recorder. The unit consists of a self-
contained battery, an electronic module and a
transducer. The battery is shock mounted and is
separated from electronic module by a bulkhead in the
case. The beacon (pinger) radiates a pulsed acoustic
signal into the surrounding water upon activation of its
water-sensitive switch and will activate automatically
on submersion in salt or fresh water with an operating
life expectancy of 30 days to a depth of 20,000 feet.
Section III. NAVIGATION
3C-13. ATTITUDE AND HEADING REFERENCE
a. Vertical Gyro System. The pilot's and
copilot's vertical gyro systems are independent and
powered by the ac power bus located in the nose
avionics compartment. The purpose of the vertical
gyro systems is to provide the pilots with visual
indications of aircraft pitch and roll attitudes on the
flight director indicators. The gyroscope develops
through synchros, pitch, and roll signals representative
established by two gravity sensitive switches that
control a torque motor for each gyro axis. High or low
erection rate of the gyro is accomplished by applying
high or low voltage to the respective torque motor.
Panel mounted switches, placarded NO. 1 (pilot) and
NO. 2 (copilot) V GYRO FAST ERECT, provide the
means for fast erection of the gyros. Pressing the
FAST ERECT switch will erect the gyro to within 1.0°
of pitch and roll within 60 seconds of power
application, and erect to within 0.5° within 2 minutes.
b. Gyro Magnetic Compass System. Two
directional information for the aircraft at all latitudes of
the earth. For heading reference, two modes of
operation are used: directional gyro (FREE) mode, or
slaved (SLAVE) mode.
(1) In areas where magnetic references are
reliable, the system is operated in the SLAVE mode.
In this mode, the directional gyro is slaved to the
magnetic flux valve that supplies magnetic reference
for correction of the apparent drift of the gyro. In
FREE mode, the system is operated as a free gyro. In
this mode, latitude corrections are manually introduced
using the INCREASE / DECREASE switches located
outboard of each HSI. The SLAVE/FREE mode is
selected as desired using the SLAVE / FREE switches
also located outboard of each HSI. Both compass
systems (No. 1 and No. 2) are ac power dependent
and are powered by the selected inverter.
(2) Gyro compass 1 provides heading
information for the pilot's HSl and copilot's RMI. Gyro
compass 2 serves the copilot's HSl and the pilot's RMI.
c. Comparator Monitor OSA. The comparator
monitor is a self-contained, five-channel, six-light
instrumentation comparator used to monitor and
compare the pilot and copilot flight in instrumentation
systems for similar pitch and roll attitude, heading,
localizer signal, and glideslope signal. A pre-
indicated by illumination of the applicable annunciator
(ROLL, PITCH, HDG GS, or LOC). The comparator
has a self-monitoring feature that checks the internal
electronics of the comparator and displays any internal
failure on an individual (MNTR) annunciator. All six
annunciators are located above the pilot's altimeter
and are tested along with the other aircraft annunciator
lights by pressing the PUSH-TO-TEST switch located
on the warning annunciators panel. An illuminated
comparator annunciator may be extinguished by
pressing the light face or, should a fault correct itself,
the light will extinguish automatically.
(1) Attitude Monitor (ROLL, PITCH). Two
separate channels of roll and pitch attitude monitoring
are provided. Each attitude channel receives input
signals from a differential resolver synchro located in
the attitude director indicator. An angular difference of
6 in roll or pitch will result in a fault indication.
(2) Compass Monitor (HDG). The compass
monitor receives input from synchros in the HSI's. A
nominal heading difference in unbanked flight of 6° will
result in a fault indication.
(3) Localizer Deviation (LOC). The localizer
deviation signals are received from both VHF NAV
receivers. The nominal fault indication difference is
approximately 1/2 dot.
deviation signals are received from both glideslope