There are four symbols used to display the threats on the TCAS display. The symbols are a hollow white
diamond, a solid white diamond, a yellow circle, and a red square. These symbols are accompanied by
information that indicate whether the threat is ascending or descending and also the difference in altitude.
An arrow to the right side of the threat symbol indicates the altitude variance of the threat. The arrow
points up if the threat is ascending and points down if the threat is descending. The number above or
below the symbol indicates the difference in altitude. The number is above the symbol to indicate a
positive altitude difference and below the symbol to indicate a negative difference in altitude.
3.81.1.
TCAS Threat Setup
1.) Select one of the preset threat model direct entry buttons located to the right of the TCAS
map.
2.) If a threat ATC Failure is desired, select prior to activating scenario.
3.) Choose the TIME TO CLOSEST POINT OF APPROACH data entry button to enter in
the desired time.
4.) Select the ACTIVATE AUTO SCENARIO direct entry button to activate the threat model.
5.) Select the RANDOM TRAFFIC direct entry button to turn the Random Traffic on or off.
3.81.2.
TCAS Map
1.) The left side of the page is used to display the selected Threat and decoys.
2.) Selecting one of the scale buttons located on top of the TCAS map sets the map range.
When a threat is active, selecting the Auto button will adjust range so all active threats will
be displayed on the plot at the highest possible resolution.
3.) The line to the right of the TCAS plot provides the ownship’s rate-of-climb.
3.81.3.
Manual Threat Setup
The Manual Threat Setup page is accessed by selecting the MANUAL THREAT SETUP page button.
See Figure 3-72. The Manual Threat Setup page is used to set the different threat’s, such as ATC Failures,
Heading, Altitude, Distance, and time to the Closest Point of Approach (CPA). Data entry buttons are
provided for entering the values for the heading, altitude, distance, and time. A direct entry button is
provided for setting up the threat’s starting position. Each time the button is selected, it will toggle between
Above, Below, Level and default values. A data entry button is provided for setting up the Threat @Speed.
A data entry button is also provided for entering the threat’s vertical closure rate. Random Traffic
(non-event) can be turned on or off, low, medium, and high. This traffic will be between 10,000 ft. relative
and within 100nm of ownship. The Number of traffic is determined by the following selections: Off (0),
Low (2), Med (5), and high (9).
TM-3-B 737-IOS1-007
TCAS
FSI-SSD
3-98
TOUCHSCREEN (NT IOS)
B 737
JAN 2001