which is concentric with the DH SET knob. The
dimming knob also dims the distance and course
display on the pilots HSI, and the altitude alert dis-
Expanded localizer. Raw localizer dis-
placement data from the navigation receiver (HSI
display) is amplified approximately 7 1/2 times to
permit the expanded localizer pointer to be used as
a sensitive reference indicator of the aircrafts posi-
tion, with respect to the center of the localizer. It is
normally used for assessment only, since the pointer
is very sensitive and difficult to fly throughout the
entire approach. During final approach, the pointer
serves as an indicator of the Category II window.
Full scale deflection of the expanded localizer
pointer is equal to 1/4 degree of beam signal. The
expanded localizer is displayed by the localizer
pointer only when a valid localizer signal is avail-
(20.) Inclinometer. Gives the pilot a con-
ventional display of aircraft slip or skid, and is used
as an aid to coordinated maneuvers.
Rate of turn. Rate of turn is displayed
by the pointer at the bottom of the ADI. The marks
at the extreme left and right sides of the scale repre-
sent a standard rate turn.
(22.) Attitude (ATT) test switch. W h en
depressed, the sphere will show an approximate atti-
tude change of 20 degrees of right bank at 10
degrees pitch-up. The ATT warning flag will appear.
In addition, all mode annunciator lights except DH
Radio altitude (RA) test switch. Press-
ing the RA test button causes the following displays
on the radio altitude readout: all digits display 8s
then dashes, and then the preprogrammed test alti-
tude as set in the radio altimeter R/T unit, until the
test button is released at which time the actual alti-
tude is displayed. The DH display during the test
displays all 8s with the altitude display and then
displays the current set altitude for the remainder of
the test. RA test is inhibited as a function of APR
Decision height (DH) display. The dig-
ital DH display, displays decision height range from
0 to 990 feet in 10 foot increments. The decision
height is set by the knob in the lower right corner of
Symbolic miniature aircraft. Serves as
a stationary symbol of the aircraft. Aircraft pitch
and roll attitudes are displayed by the relationship
between the fixed miniature aircraft and the mov-
able sphere. The symbolic aircraft is flown to align
the command cue to the aircraft symbol in order to
satisfy the commands of the selected flight director
Glide slope scale and pointer. Displays
aircraft deviation from glide slope beam center only
when tuned to a ILS frequency and a valid glide
slope is present. The aircraft is below glide path if
pointer is displaced upward. The glide slope dot rep-
resents approximately 0.4 degree deviation from the
3-20. COPILOTS GYRO HORIZON INDICATOR.
a. Description. The copilots gyro horizon
indicator (fig. 3-13) is a flight aid which indicates
the aircrafts attitude. The attitude given is in rela-
tionship to an artificial horizon. There are no front
panel fuses or circuit breakers provided for the copi-
lots gyro horizon indicator.
b. Indicators and Functions.
(1.) Bank angle scale. Indicates aircraft
bank angle from zero to 90 degrees with marks at
10, 20, 30, 45, 60, and 90 degrees.
(2.) Bank angle index. Reference indicat-
ing zero-degree bank.
Bank angle pointer. Indicates aircraft
(4.) Horizon line.
Affixed to sphere,
remains parallel to the earths horizon at all times.
(5.) G flag. Presence announces loss of
(6.) Sphere. Indicates orientation with
earths axis at all times.
(7.) Inclinometer. Assists the copilot in
making coordinated turns.
(8.) Miniature aircraft. Indicates attitude
of aircraft with respect to the earths horizon.
3-21. TURN AND SLIP INDICATORS.
Description. The pilot and copilot have
identical turn and slip indicators (fig. 3-14) pro-
tected by the circuit breaker placarded TURN &
SLIP on the overhead circuit breaker panel (fig.
b. Controls/Indicators and Functions.
(1.) Two-minute turn marks. Fixed mark-
ers indicate two-minute turn rate when covered by
turn rate indicator.