caused by continuous or inter-
mittent condition. Intermittent
conditions light lamp until reset
by TEST switch. If continuous
condition does not degrade atti-
tude operation, lamp goes out
when mode selector is set to
Consists of 10 keys for entering
load data into data and FROM-
"N", "S", "E", and "W" (on keys 2,8,6 and 4) indicate
direction of latitude and longitude. TAC and DISP (on
keys "7" and "9") enable loading and display of TACAN
station data. MV and DISP (on keys "3" and "9") are
associated with loading and display of Magnetic
Variation and Magnetic Heading. GRID and DISP (on
keys "5" and "9") are associated with loading and display
of UTM coefficients.
When pressed, illuminates and
erases data loaded into data dis-
plays or FROM-TO display.
Used to cancel erroneous data.
After clearing, data loading can
WYPT CHG key
When pressed, enables numbers
in FROM-TO display to be
changed. If INSERT/ADVANCE
key is pressed, computer will use
navigation leg defined by new
number in all navigation compu-
tations. If INSERT/ADVANCE
key is not pressed, computer will
continue using original numbers
in all navigation computations;
but distance/time information,
based on new leg, may be called
up and read in data displays (in
case of waypoints). When not in
TACAN mix mode, TACAN sta-
tion number is inserted to dis-
play DIS/TIME information.
This is a dual purpose control.
When the knob is pressed in-
ward, the TEST switch function
is engaged. When the knob is ro-
tated to either the AUTO or
as a selector between those
Selects automatic leg switching
mode. Computer switches from
one leg to the next whenever
waypoint in "TO" side of the
FROM-TO display is reached.
Selects manual leg switching
mode. Pilot must make
waypoint changes manually.
When pressed, performs test of
INS lamps and displays, remote
lamps and indicators controlled
by INS, and computer input/
Used with other controls to activate display of
numerical codes denoting specific malfunctions and
resets malfunction warning circuits.
During alignment, activates the HSI test. Continued
pressing of switch provides constant INS outputs to
drive cockpit displays in a predetermined fashion.
The INS can provide test signals to the
connected displays. Pressing TEST switch
during Standby, Align, or NAV modes will
displays to indicate "8's" and illuminates the
HSI and ALERT lamps. Additional HSI test
signals are provided when INS is in Align
and the data selector is at any position other
than DSRTK/STS. Under those conditions,
pressing TEST switch causes the HSI to
indicate heading, drift angle, and track angle
error all at "0°" or "30°". At the same time,
cross track deviation is indicated at "3.75"
nautical miles (one dot) right or left and INS-
controlled HSI flags are retracted from view.
Output test signal are also supplied to the autopilot
when INS steering is selected. Rotating AUTO/MAN
switch to AUTO and pressing TEST during Align
furnishes a 15° left bank steering command. A 15° right
AUTO/MAN switch is set to MAN.
Display numbers defining
waypoints of navigation leg be-
ing flown or in the case of a
flashing display, displays TA-
CAN station being used.
Waypoint numbers automatically change each
time a waypoint is reached. Unless flight plan
changes during flight, the automatic leg switching se-
quence will always be 1 2, 2 3, 3 4....8 9, 9 1, 1 2,
Selects data to be displayed in
data displays or entered into
INS. The rotary selector has 10
positions. Five positions (L/L