TM 1-1520-218-10
3C-207
(3) A traffic display and a resolution advisory
display are provided to the flight crew. The traffic
display consists of the relative position of mode A/C
and mode S transponder-equipped aircraft around the
TCAS equipped aircraft. The resolution advisory
display indicates the appropriate vertical maneuver or
restricted vertical speed range to avoid a threat.
(4) Only operating mode A/C or mode S
transponders that provide altitude information will
generate resolution advisories. Only traffic alerts will
be generated by mode A/C or mode S transponders
that provide no altitude information or by aircraft
without transponders.
b. TCAS II Controls and Functions.
(1) Controls and functions of the TTC-920
are illustrated in Figure 3C-150 and detailed in Table
3C-107.
Figure 3C-150. TTC-920 Transponder/TCAS Control
Table 3C-107. TTC-920 Transponder/TCAS Control Switch Descriptions
SWITCH
LEGENDS
FUNCTIONS
1
Altitude Enable Switch
ALT / OFF
Enable altitude reporting on transponder.
2
Transponder
Enable
Switch
1 / 2
Enables #1 or #2 transponder.
3
Fail Indicator
ATC FAIL
Indicates failure in transponder, control panel,
antennas, or air data system when lamp remains lit.
4
Identification Button
IDENT
Enables transponder IDENT.
5
TCAS/ATC
Mode
Select Switch
0000 through 7777, as
selected
Selects transponder code displayed in window.
6
Function Select Switch
TEST / STBY / XPDR/
TA / TA/RA
Selects indicated functions. TEST and STBY apply
to both TCAS and transponder. XPDR turns on
transponder and leaves TCAS in standby. TA
equals TA only. Other positions enable TCAS and
transponder.
