TM 55-1510-215-10
7. Radio altimeter
TEST
switch
-
(5) Aural "GLIDESLOPE" advisor (mode 5).
Release.
The aural advisory "GLIDESLOPE" indicates that the
aircraft has exceeded 1.3 to 1.5 dots above or below the
c. GPAAS Modes of Operation.
The GPAAS
center of the glideslope beam. The glideslope advisory
operates in the following modes of operation:
is armed when a valid glideslope signal is detected and
the aircraft is below 1000 feet AGL. It will be repeated
(1) Aural "TWO THOUSAND" advisory
no more than three times at 4 second intervals unless
(mode 1).
The aural advisory "TWO THOUSAND"
the aircraft is returned to less than 1.3 to 1.5 dots from
indicates that the aircraft is at a radio altitude of 2000
the center of the beam. The glideslope advisory is
feet above ground level. This advisory is cancelled
disabled upon loss of a valid glideslope signal, during
when valid information from the radio altimeter is lost,
climb, on a localizer back course, below the decision
during climb, or whenever the aircraft is out of the
height set on the radio altimeter or, if the navigation
operating altitude range of the radio altimeter.
receiver is not tuned to a localizer frequency. This
advisory is inhibited by the weight on wheels strut
(2) Hundred foot increment aural altitude
switch.
advisories (mode 2).
The aural advisories "ONE
THOUSAND, NINE HUNDRED, EIGHT HUNDRED,
(6) Aural advisory "MINIMUM, MINIMUM"
SEVEN HUNDRED, SIX HUNDRED, FIVE HUNDRED,
(mode 6). The aural advisory "MINIMUM, MINIMUM"
FOUR
HUNDRED,
THREE
HUNDRED,
TWO
indicates that the aircraft at the radio altitude selected by
HUNDRED, ONE HUNDRED" indicate that the aircraft is
the crew with the radio altimeter indicator decision height
at the associated radio altitude in feet above ground
knob. This advisory is cancelled when valid information
level. This advisory is cancelled when valid information
from the radio altimeter is lost, during climb, whenever
from the radio altimeter is lost, during climb, or whenever
the aircraft is above 1000 feet AGL, or whenever the
the aircraft is out of the operating altitude range of the
aircraft is out of the operating altitude range of the radio
radio altimeter.
altimeter.
(3) Aural "LOCALIZER" advisory (mode 3).
(7) Aural "ALTITUDE, ALTITUDE" advisory
The aural advisory "LOCALIZER" indicates that the
(mode 7). The aural advisory "ALTITUDE, ALTITUDE"
aircraft has deviated from the center of the localizer
indicates the approach to a preselected altitude as the
beam in excess of 1.3 to 1.5 dots. The localizer advisory
aircraft reaches a point 1000 feet from the selected
is armed when a valid localizer signal is detected and
altitude or, after reaching the selected altitude, when the
the aircraft is below 1000 feet above ground level. It will
aircraft deviates more than 250 feet from the selected
be repeated no more that 3 times at 4 second intervals
altitude.
unless the aircraft is returned to less than 1.3 to 1.5 dots
from the center of the localizer course. The localizer
(8) Aural "CHECK TRIM, CHECK TRIM,
advisory is disabled when a valid localizer signal has
CHECK TRIM" advisory. The aural advisory "CHECK
been lost, during climb, below the decision height set on
TRIM, CHECK TRIM, CHECK TRIM" indicates that the
the radio altimeter, or if the navigation receiver is not
autopilot has had a trim failure.
tuned to a localizer frequency.
(9) Aural "AUTOPILOT" advisory. The aural
(4) Aural "CHECK GEAR" advisory (mode 4).
advisory "AUTOPILOT" indicates that the autopilot has
The aural "CHECK GEAR" advisory indicates that the
disengaged.
aircraft has descended to 500 feet AGL and the landing
gear is not down. This advisory is repeated once at 100
d. Emergency procedures . If an emergency or
foot intervals down to 100 feet AGL.
malfunction makes it necessary to disable the GPAAS,
pull the G.P.A.A.S. POWER circuit breaker located on
the instrument panel (GPAAS audio may be turned off
by depressing the VOICE OFF switch).
3-42 Change 9
